Minutes of Weekly Meetings - DarkLight-EXP/wiki GitHub Wiki

This page contains the minutes from all DarkLight meetings, with most recent meetings at the top. Please feel free to add details if they are missing, and to add links to materials where possible.

May 30, 2025

Chairing today: Kate

Mike to Michael: worried about the cable tray. How many HDMI cables? 24 total HDMI, 4 cables for 6V power supply.

Are power cables insulated? The magnet power supply ones are
Laura: going to wire the big ones today so let’s see where they put them and then go from there.
Mike: does it prevent us moving the vertical spacer if they put them in today? Laura: doesn’t think so
Michael what do you need, 4 SHV? Michael: yes. Mike: we’ll need to extend them, the 19m isn’t enough, but we can do that easily.

MIT

Transducer status? No news.
Jim has no replacement
Doug will order resistive POT and see if Brian can modify the target ladder to take it
Hubert can modify the box
What else does Brian have to do?
- Laura: finishing radiation shielding support this morning, adjusting brace. Backing plate for the magnets. Might also make a support for the beamline
- Test fit the detector stand? Can’t til everything else is in place.
- Laura: frame is not coupled to the shielding stand. Mainly supported by bolts into the actual dipole frame.
- Take offline.
When do the vacuum boxes go into the magnet? Today? Probably, but table first

Mike to Stephanie: where can we unroll the 75 foot cables? Have to unwind them to put them down the hole. Use cyclotron roof beams

Mike to Jan and Laura: when do we need what

PPG32 is top priority. Don’t need a hardware modification, only need to flash the new firmware.
- KO said he’s working on this.
DAQ second priority.

Doug: have we installed a spectrometer vacuum chamber yet? Laura: no, will probably happen today.

D: will Tony align it? Yes. Tables are aligned so it’s just next step to align relative to that.

VXS crate showed up in Louisville KY

May 21, 2025

Chamber leak checking

Mike: Brian did some welding to fix two leaks. Went to the welding shop and was able to equipment
Doug P: not sure yet, finding out
Doug H: appears to be a big leak on one of the flanges from the scattering chamber. Suspicion is that Ancorp’s weld broke in shipment or during cleaning. Large enough leak to make it hard to leak check anywhere else. Took chamber mostly apart yesterday and moved it to the weld shop. Brian O’Rourke (MIT welder/technician) will try to fix it, working with TRIUMF welder.
- Will then have to disassemble and clean again because welding makes a mess
- Gauges will come off but the rest is more or less OK. Bellows annoying but can’t come off.
- Ernie and Jim discussed causes: Doug thinks the weld isn’t great anyway. Brian should be able to fix it. Ernie doesn’t think that it will even make a mess.
Because they took off the target ladder to go to the weld shop, Doug was able to get a good look. Possible solution to target location issue: going to get a spacer made
Doug H wants slow open to vacuum and venting rather than sudden as it will blow out targets. Doug going to talk to Derek from vacuum. Right now they don’t.
Continued discussion on needs and what is currently available
Ethan: removed gauges from chamber, Brian is working on it.

Trigger

Moving along, final opinions on cooling systems/fans
Both arms constructed and in frames, wrapped and ready to go
Some final tests on noise, some of them have more than expected. Hopefully not light guide breakage
If KO available today, going to move triggers over and couple with gems
KO and Mike looked for fans today and found some 6 cm square with good airflow. Gabby to direct Andy
Moving over to GEM lab this afternoon. Kate to help with vacuum chamber cleaning so Ethan

GEMs

Shipped 4 boxes last Wednesday: box with GEMs, VXS crate, big crate, box of HDMI cables. Two lost by UPS: GEMS and VXS crate. Turned up eventually thanks to old stickers. VXS crate is still unaccounted for. Michael has bag of electronics on him that he will bring on Sunday
Manju and Ethan and Laura keeping an eye out for delivery
Planning to set up a VXS-based optical readout system at JLab too
At TRIUMF: Laura has rewritten all the code. Ethan and Manju see a low efficiency here too but it seems impossibly low so he is wondering if it’s an analysis issue rather than a DAQ issue
Michael: term efficiency is very delicate, how is it defined? Ethan: doesn’t have a presentation at present but the short answer is it should be better than this as it is defined and as it is being tested.
Documentation/e-log? Ethan: google doc for GEMs at TRIUMF, mostly looking at setup not development.
TODO Mike: follow up with KO on setting up an elog.

Elinac news

Nothing at present
Collimator: Laura to follow up
Beam pipe pieces being made as we speak by Devon

Outreach and photos

Take pictures of nice things! Post them to Gabby’s Google drive!

May 14, 2025

TRIUMF working on assembling chamber
1. Turns out the guide rods for the target ladder are too long
2. Laura is having the shop cut it down to size, removing about an inch
3. Once that is done the chamber should be leaked checked
4. Permanent quads are nearly ready to install, double checking alignment
5. Also fixed the holes for the fiducial markers
6. Jim suggested some edits for the document that TRIUMF wants MIT to sign regarding the equipment being sent
7. Joe is double checking the fiducial on the dipoles, but they should work
8. Richard wondering about procedures for work permits
GEMs
1. Ethan has established six frame readout and is working on double word packing for data reduction and readout speed improvements
2. Ryan is packing GEMs and should ship them today or tomorrow
Stony Brook
1. Need to fix some code issues with a recent pull request from Sid

May 7, 2025

Bates
1. APV support is fabricated and at Bates
2. Tony is going to take of steering magnets
3. Sent a bunch of o-ring and window spares already
  1. Waiting to see if Doug found them at TRIUMF, should be there
Trigger update
1. Doing light leak checks
2. Going to move over to GEMs when Laura is ready
3. Welcome to Sidney, summer student!
4. Is masking tape light tight? Likely not. Need something to seal the scintillators
  1. Likely not masking tape, find something else. Ask optics people
Jan’s work permit
1. Some progress, waiting to hear if new passport causes an issue
Bishoy
1. Test out the new cooker updates with new .ini files
GEM Group
1. Michael has most orders in
2. GEMs should be shipped by the end of the week (nope, see below)
Laura
1. Beam line being disassembled
2. Bottleneck on mechanical services, details being sent by Laura now to move things along.
3. Leak checking ongoing
4. Arms being moved down to the hall
5. Doug and Sid working on bellows supports
6. Next week is reassembly of beam line for DL
7. Collimator will arrive later in the week - then will be reinstalled
8. Was wondering if there are spare o-rings available. Not needed for installation, just as spares
MIT
1. Ernie sent a big package of info on magnet designs this morning
2. Helping with mechanical services
Stan
1. Are hall probes at TRIUMF? Yes, and they can be mounted
Doug
1. Should move the magnets down
2. Yes and they will be there
Michael
1. Confirms that shipment being prepared, won’t be shipped until next week
2. Some things will be brought with Manju in luggage

April 30, 2025

TRIUMF
1. Mostly done with cleaning
2. Ehall is essentially ready for us to move into
3. The hatch will need to be opened to access collimator area
  1. Schedule for Monday
  2. Collimator still being welded. Needed to wait for jogs that should have arrived today
  3. Beam pipe section needs to be welded at UBC
Bates
1. New APV support is going to be machined at Central Machining ordering stock now
2. Jim will bring it out with him, not shipping
TRIUMF again
1. Delay testing out Konstantin’s module
  1. Needs to be updated to produce LVTTL clock out
2. Unclear why delay, do we need to actually install a new OS on VME computer? Maybe need to network boot, but servers are on separate network from DAQ at this point, might be connected by end of week
3. Should be that a spare module can be updated at Konstantin’s desk and inserted. Seems Konstantin wants to use VME scripts to reprogram the one sitting in the crate.
4. Need drivers for new OS, unclear where they are
5. Jan believes VME computer is 64 bit architecture even though it is booting 32 bit OS
Person power
1. Do we have enough people to actually run?
  1. We hope so
  2. Hopefully have enough operators to run 24/7
    1. 2 for June for commissioning
    2. 3/4 fully trained in principle
  3. Summertime will be hard for operators
  4. Fall will be hard for DL shifters
GEM Group
1. Orders are being made now, just approved yesterday
2. Preparing to select items for shipment, hopefully happening next week
3. Shipment should still arrive when Manju does
Funding
1. How much carryover exists?
  1. Jan has maybe 30k
  2. Michael has maybe 40k from two years ago, 60k from this year. Maybe 100k
  3. Totally unclear what the true status is

April 23, 2025

MIT
1. Have a plan for the APV supports
2. Jim wants to hear from Joe about what Joe has done before moving forward
3. Joe is on vacation for the next week and a half, so unclear when this will actually get done
4. Still on schedule for deconstruction of beam line in first week of May
5. Collimator may take a little longer than anticipated, may interfere with deconstruction as shielding blocks need to be craned out
Collaboration Meeting
1. Set for July 2-4, maybe cut the 4th depending on agenda
Maybe a mini-post installation meeting on May 29?
1. Laura will send around a poll
Cleaning chamber progressing
1. Needed to order a conflation for the top of the chamber
Ernie is putting together a magnet data sheet
Trigger paddles
1. Tomorrow Gabby and Mike are putting trigger paddles into the frame
2. Is the TDC understood?
  1. Not completely, Konstatin feels it is well understood so things can be installed and maybe moved to above GEMs
Jim appears and wants all emails between Laura and Joe
1. Seems to want to wait for Joe
Ross is wondering about travel dates for him
1. Suggested first or second week of June
Michael Kohl
1. Shipment hoping to get in before May 13
2. Hoping to get it out within the next week
3. Orders have not all been placed yet
  1. Waiting for paperwork
4. Still need to select which 3 GEMs to ship
Ethan
1. Needs to send around the TRIUMF Presence sheet
Work permits/computing accounts
1. Jim and Brian are mostly setup, will need to do in person training when they arrive
2. Work permits otherwise are in progress, radio silence from HR at this point

April 16, 2025

NSERC Review Comments
1. Mike is sending around the NSERC review comments to the non-Canadians for their reference
Friday and Monday are days off for UBC/TRIUMF
Jan needs to write DOE progress report
1. Needs to explain why we are late
2. Plan is still to leverage JLab to help fund 50 MeV
  1. Ongoing details TBD
  2. Bob is in contact with JLab and it looks like TRIUMF can afford to make some necessary changes
  3. Still need to bring it to TRIUMF and install it
  4. Michael Kohl’s carryover is in an unclear state
    1. Need’s some follow-up with JLab people
    2. Might be able to involve a student on design work
3. Jan has some money from last year, but was encouraged not to spend it
  1. Is encouraged to come up with obligations for this money and include this in yearly update
4. Run toward end-ish 2027
5. TRIUMF is shutdown all of 2026
Doug met with Joe about APV backplane supports
1. Encourages a meeting between Bates and TRIUMF to confirm dimensions and what needs to be modified
2. Joe shows the design and confirms a few details with Laura
3. Reconfirm that the only issue is the slots that connect the APV support to the GEM
4. Laura will communicate with Joe
Laura is coordinating with service groups to get things ready for installation
1. Took apart target chamber yesterday and will hopefully start cleaning later today
2. Will meet with Jim to discuss cleaning spectrometer
3. Steffie mentions TRIUMF would like a plate on the magnets with nominal operating parameters, wondering how to attach them
4. Ethan asks about mapping the other magnet
Michael has submitted all his requisitions, and they are being processed by Hampton
1. Jan asks to see Michael’s DOE progress report so they can coordinate
2. Manju may go out on May 5? Might change dates depending on shipping dates
3. TRIUMF electrical services needs to inspect power supplies before they can be installed, so should be sent soon
4. Might have some spare APV cards from Hall A to be sent ASAP, and maybe further spares later
5. MPDs, might have three extra at JLab in his group. Others are being repaired, should receive 5 back at some point
6. Ryan is looking at GEMs at Hampton to identify best 3 to see which to send
7. Michael plans on arriving on May 19
8. Everyone should book TRIUMF House sooner rather than later
Konstantin wants to update OS on VME crate computer before the PPG32 clock can be tested
1. Unclear when this will happen or what OS to use
Gabby
1. Needs to talk to Konstantin about trigger data format
2. On track to have things ready for installation
MOU
1. Need signature from TRIUMF
2. Laura in talks with Anne about signing
Win and Bishoy
1. Had a hackathon last week to develop code at SBU
2. Some strange bugs in Sid’s computer running cooking
3. Overall quite productive
PADME Results
1. Obviously not convincing, but not ruling anything out
2. Keep going!

March 26, 2025

Jan chairing

MIT

Doug will make a list of people coming to TRIUMF so that Laura can add as visitors
Magnet: mostly resolved. Ethan will do some fine-tuning. Absolute scale is still an issue. Shaquielle will do new power supply and proper ramping procedure. Hopefully that should solve the scale issue.
Windows sent to TRIUMF were a spare set.

TRIUMF

Laura has meeting with Steve re:computers on Friday
Had meeting with electrical services last week, ball is rolling there
Tube is still missing
Will send numbers from Ethan regarding dose on the cables to electrical services
Stephi: new operator is trained
Gabby: triggers are almost ready to fuse with the GEMs once Laura is ready and a couple things have been ironed out

Hampton

Had a power outage, so had to restart run. Everything booted back up and taking cosmics again.
Timeline still on track for shipping to TRIUMF
Doug H: do we have spare APV cards? Laura has a couple at TRIUMF, should check on if we can find some more.

SBU

Win: working on mass reconstruction code still with SBU crew, Bishoy will also have update for simulation meeting.
Doug H: how’s the slow control? Jan: waiting on computers to be plugged in. Laura will hopefully have this resolved on Friday, otherwise she will find an interim solution.

March 19, 2025

Laura chairing

MIT

Shipping o-rings soon
Ethan (magnetic field): see power supply issues from integration meeting, think it makes sense to switch over to the other dipole. Ernie: we don’t think there’s anything actually wrong with the magnets? No, power supply issue. Think we should change to the MIT power supply. After fit, we see better agreement. See discussion from integration meeting.
Doug to Ernie: did we test the hall probes at MIT? No.

TRIUMF

Gabby: efficiency studies ongoing, working on the frame design with Philip.
Laura: new frontend for the GEM code is making progress, but still debugging

Hampton

Dulitha: testing 2 GEMs that returned from CERN, done latency scan and now running cosmics. Will look at data tomorrow.

March 12, 2025

Jan chairing

TRIUMF

Gabby: Crazing not a problem, finishing assembly and finalizing frame designs
Laura: see integration meeting minutes

MIT

Jim uploaded some updated analysis for vacuum studies and seismic analysis
Ethan: Laura requested some cable dose measurements for electrical services, think this is just a sanity check for them was Laura’s impression. If it is not too taxing to do, think we should just provide this for them.
Ethan summarizes magnetic field status from the last couple weeks (see previous mintues)

Hampton

Have GEMs on N2, if HV goes well can take data with ArCO2 starting next week

SBU

Working on some simulation documentation
Win will send around APS slides later today

March 5, 2025

Laura chairing

MIT

Good agreement between Ansys and COMSOL calculations for the B field. Agrees with the bulk of the field map values between the pole tips. Still 30-50 G difference off the pole tips in the area where the coils are. What’s the difference? Ernie has a slightly different BH curve from Buckley can see if that changes anything. Don’t believe that will change anything, but worth checking.
Shaquielle did some debugging on the TRIUMF side.
MIT will be having a separate meeting to hammer this out.
Energizing magnets: ramp them up to 225 A and then ramp them back down to 200 A to allow everything to stabalize. Laura will check with Shaquielle about what he’s doing.
Doug is here the 16th to 21st

SBU

Simulation: looks like some pull requests that got merged recently. Daniel is busy fixing a strange bug seen with Mac. We need to clean up the messenger class, work in progress.

Hampton

Trigger setup finished. DAQ is good as well.
Now have access to Sr source.
2 GEMs are now in nitrogen. ArCO2 in prep for second gas line.
Still working on cable/power supply acquisition
Two VTP boards were delivered this week. Looking for controllers. Will focus on this once GEMs are sent to TRIUMF.
Ship via Fedex Express in early April, VXS setup sent later in the summer

TRIUMF

Waiting for new calibration from KO
Crazing seems to have minimal effect on the timing resolution, some other issue but this seems unrelated
32 channel readout is up and running, DAQ is up and running as expected.
Some high temperatures, but table is quite disorgainzed, but will start working on fan configurations. Will work on fan design to go on MIT frame.

February 26, 2025

Laura chairing

MIT

Shipment is hopefully progressing. Some questions about payment and the packing list.

TRIUMF

No trigger news. Haven’t heard back from KO about the ethernet cables.

SBU

Merged 2 PRs that were in progress. Most updated field calculation is now in G4. Trigger frame is now in as well. Most up-to-date solidworks model is in the process of being implemented.

Hampton

Started to set up trigger scintillator and trigger logic and the DAQ chain.
No internet yet
Still working on gas supply, then have to run nitrogen for some time before voltage can be applied.
Sr-90 source acquired.
Still shopping for cables and power supplies
Shipping now scheduled for end of March
Latching module: Laura needs to finish up latency scan and then link up with KO regarding testing rev 2 instead of rev 1.

AOB

Doug H will be coming out to TRIUMF on the 16th of March. Ethan will come a couple weeks later.
Need to hammer out dates for installing/commissioning for budgeting purposes.
Laura will need to send out email to collect who needs invitation letters and who needs visitor status for installation.

February 19, 2025

Laura chairing

MIT

Crate is due to be picked up later today by the shipper. Should ship either tonight or tomorrow. May arrive at TRIUMF on Monday or later that week.
Doug will come out to TRIUMF in mid-March, Ethan will come in at end of March.
Technical package: no updates. Engineering approval may be a bit more complex than we were originally assuming, need shortly.
Magnetic field: Holger sent along Comsol sim, will compare.

TRIUMF

Trigger: can now hook up all 16 scintillators at once, KO made new analysis module.
High strength PMQs arrived yesterday, passed to Tony.
GEMs: working on latency scans and getting second GEM up and running.

SBU

See simulation meeting minutes

Hampton

Work permits now active and have workspace.
Have unpacked the GEMs, are working on getting gas supply. Need to get cleared by safety. Should have by end of week.
Working on getting Sr-90 source.
Still shopping for cables and adapters, but should be soon
VXS setup: need controllers.
Schedule has slid somewhat due to delay with gas, shipping will now be at end of March.

February 12, 2025

Laura chairing

TRIUMF

Midas was down last week, now back up and running. Working on getting everything powered, should be able to take tests next week.
eLinac: setting up for 3 days of continuous beam delivery at 27 MeV. Had some trouble with coldbox, now resolved.
Everything was submitted to CNSC, waiting.
Laura will send out doodle poll for integration

MIT

Finishing putting the packing, everything is loaded. Then need weight and then it will ship out hopefully by Friday
Continuing to work on putting together the analysis
Ethan, magnetic field: difference between mapped field and calculated field is now sub 1 cm. Scaled up calculation to account for the 200A measurement vs the 190A calculation. Things look better but still some open questions.
Good to ask Shaquielle for another map, but want to agree on what the request should be so we don’t bombard him.
Would like 3D mapping, think we can get 2D but probably not 3D.
Doug H: verifies magnets are working, verifies shape, verifies magnitude. We’ll never use these anywhere. Won’t put it into the MC or the reconstruction. Jan disagrees, if we have a nice map we can put it into the simulation. Doug: would need 3D map. Probably another 15 or so measurements. Jan: C-slit, so don’t know the angles and they play a big role in the reconstruction. Doug: should get that from the calculated field. Jan: only if we trust it. Depends on how much work we can get, the rate of work we can do is limited. Time wise it might not be possible. Richard: completely independent calculation by Holger in COMSOL, worth comparing with Xiqing’s calculation.

SBU

Win: no updates, sim meeting last week: a couple new pull requests. See minutes there.

Hampton

Four GEMs have been moved to JLAB, package had been squeezed on one corner, but hopefully interior is all fine.
Work permits are nearly final
Organizing workspace
Have been shopping for cables, adapters, and power supplies.
90 degree, angled cables only available from Amazon, adapters are available from more official places. Delivery to Canada from digikey Canada is maybe not possible.
Timeline: Hooking up the 6 GEMs to N2 for a week. JLAB approval needed, so have started that. Hopefully will have sometime next week. Set up DAQ and prepare trigger next week. Week of the 24th, test everything and then ship stuff to TRIUMF in the first week of March.
Have been some discussions about loaning some PPG32 modules from TRIUMF. Lending one module to HU until end of 2025 if possible. Jan is pretty sure LV TTL is what the MPD needs. Configurable for the trigger input but not the clock. Think the lack of NIM is hardware issue not firmware. Schedule a meeting with relevant parties for sometime next week.

February 5, 2025

Jan chairing

MIT

Packing things up. Going a bit slow as photos need to be taken as pieces go into the crate. Hope to ship by end of week.
Drawing package: some discussion yesterday. Joe is working on making an all-inclusive package, but dealing with computer crashes. Jim was going to try to make a package without the TRIUMF parts, working on it. All coordinates relative to the cross over point.
Should be all in the dropbox now.
Ethan: magnetic field comparison. Taking over this from Laura. Doug emphasizes that need to use mag field calculation from Jan 9. Laura: the 25. deg angle is correct. Maximum is slightly off between simulation and measured. Still seeing differences. One difference: dropoff in the measurement, a single step around x = -55 mm, maybe a probe error? Need to clarify whether it is a 3D probe or not.

TRIUMF

No updates on the trigger this week

Hampton

Four GEMs have arrived back at Hampton from CERN.
Two VXS crates were delivered as well. Need to get them tagged and moved to JLab
Working on work permits for continued GEM work.
Working on HDMI cables.
LV power supplies and cables: estimating 300 m of 12 AWG. Can probably use 24 AWG for the sensing. Jan: can buy cable with two thick ones and one thin one in it.
Can TRIUMF send Hampton 2-3 of the latching modules?

January 30, 2025

Laura chairing

MIT

Crates arrived yesterday, and are in the process of packing, need to hunt down a few things. Will be packing the next couple days, should go out next week.
Discussion about import taxes
New magnetic field map from ANSYS with the updated yoke design. New coordinate system, the MC will need to be adjusted accordingly. Ethan will add to G4.

TRIUMF

Server location discussion is moving forward
Triggers: coincidence module is all fixed up can do final assembly next week.
Mike: Peter (electronics) did measurement of cable heating 12 gauge with 4 wires, put in series put 5.1 A through it. 20 m long. Hottest part was at 31.8 deg, 8 deg temp increase from room temp. Going to pass it along to Mel and make sure he’s happy with it. What’s the voltage drop? Around a volt, for two lengths (40 m). Regulated on the distribution board. Found a coil at TRIUMF, might be enough for 80 m.
Laura: cable question with the GEMs. What number of left angle vs right angle HDMI connectors to GEMs?

Hampton

Rui opened the final GEM that actually had issues, shocked it and now it’s all good.
So all four GEMs are good now. He’s going to do some more tests this week but if everything is good all four GEMs will be sent back in working order.
Will setup on the bench at Hampton once they are received, then will select best 2 plus one spare and send to TRIUMF. Keep 3 at JLab for duplicate setup and for DAQ R&D.
Michael’s training is finished, and Dulitha is also finishing his training. Ryan is done.
GEM meeting with TRIUMF now on Thursdays.
Ordered QSFP payload boards for optical readout upgrade. Collecting APV signal before readout.
Requested PO updated for VTP order for Xilinx FPGA price increase.

January 22, 2025

Jan chairing

MIT

Joe is sick, which impacts the shipping coordination. Expect delays but Jim is going to help out.
Jim found a company that can do the collimator weld, but TRIUMF found someone who can hopefully do it in house. This will be the backup if the TRIUMF option doesn't work out.

TRIUMF

Need to make a decision about JLab and the MOU. Should incorporate some JLab people in the ammended version of it to be released at a later date. Mike will follow up with Oliver K.
Server position: Stephi: Mike from controls says the servers need to be locked so we need to confirm with Steve that our setup is ok. Mike thinks Steve approved this for us last summer.

GEMs

Got GEM readout working at TRIUMF at the end of the collaboration meeting by setting the latency much higher (using 9 vs. 5 or 6). Turned HV up to 3800 V as well.
Using a trigger scintillator above and below the GEMs so they can look at tracks straight through. Took a run with the triggers covering along one short edge and then sliding it down to cover a different region, observed pedestal mapping across the GEM.
Jan: cleaned up some of the GEM software with Laura
Mike H: why aren't we collecting data overnight? Answer: DAQ does not stay stable for that long.
Latching integrated into the GEM DAQ
Jan: cleaning up MUSE code for use in the GEMs
Laura: getting at error that kills the frontend, am investigating.
Jan believes this is due to an incomplete event being read out, advises to add a check that we have enough words in the readout routine before continuing
Michael: has heard from Rui, 3 of the 4 had black electrical tape on them which was causing issues, cleaned up the soldering residue and replaced electrical tape with Kapton, no further issues found
Only one has a short and needs the foils replaced
Hoping to get the 3 GEMs back within a few weeks and ideally test them at Hampton and them send them to TRIUMF.
Everyone is almost done JLab training, should be done by end of January.
Ryan and Laura are going to start having weekly meetings Thursday at noon EST.
Jan: does it make sense to send the ones from CERN direct to TRIUMF? Probably not. Should have a setup at Hampton.

TRIUMF (2)

Laura: cooling tube for the collimator acquired, were missing it last week, will deliver to welders
Stephi: Met with controls and vacuum group, determining what we need to integrate with the elinac. Controls can’t do much in advance because it will interrupt the running system.
Target ladder is not an issue, but other stuff. Changing anything else will interrupt the running of the eLinac.
Counting room secured, but eLinac control room backup will still be in there. May be used during the summer, but we have preference.
Debating desk configurations, going with straight desk as opposed to L-shape

January 8, 2025

MIT update

Things moving towards shipping but not before the meeting
Joe making list of what they’re shipping. Will send me the list when he has it.
Joe working on drawings right now
- Started putting together a drawing package broken down into folders
- Joe needs installation drawing instructions - to email Doug P
Jim sent Xiaxing an updated magnet geometry and she is doing the calculation.
Holger volunteered to do COMSOL calculation for magnets
Cleaning
- If TRIUMF removes PEEK from chambers, it’s in pieces and pinned together with press-fit pins. Doug suggests not taking it out. Can be cleaned in situ?
- Don’t pump on chambers without PEEK installed
- Windows have been pumped on at least 3 times now so lots of empirical testing

Hampton

Dulitha new postdoc in the group, coming from theory phd in Hampton. Will mostly be on JLab/MUSE but also “welcome to be here with DarkLight”
Michael arriving Tuesday evening, will be here til Saturday.
Lab still packed up at JLab

Stony Brook University

Not much from Jan
Ethan, Win, Jan finished most of report. Sent around.
Ethan will bring other clamps for magnets

TRIUMF

Trigger stuff
- Nothing super major, trying to get all the triggers prepared and having everything ready to go. Hope to have everything assembled by end of next week
- Integrating with GEMs? Told KO that Laura and Ethan would be working on GEMs next Mon/Tues and he might be called upon to come and help
- Do we have a scheme for latching & synchronisation? Jan and KO need to give us a plan for that.
- Jan: assumed timer on MPD works, and it doesn’t. So need to reevaluate that
- Need to discuss next week
- Set aside Friday for this
- DarkSide is winding down so we may get more of KO’s time
News from the e-linac
- Brought back the linac after the break, but beam disappeared on Monday. Gun doesn’t seem to be producing any electrons.
- Worried at first it was the cathode but it’s a big job to take it all apart. No resources for that for months. But looks like it’s possibly outside the vessel, which would be better? Will know more today. Might be ok.

Agenda

MOU: Richard to prep something
Import/export: Kate to ask Ann

ARIEL SAR

Check status on docushare?

December 18, 2024

Win chairing

SBU

No analysis update today, but there will be some student presentations soon

MIT

Ethan is traveling to Bates
James: Checking out the chambers and pumping. No shipment until the New Year, but it will be done at the beginning of January, possibly before the collaboration meeting.
Joe: Finishing up the lead shielding (for GEM and Trigger) design. New drawing file will be set out soon!

TRIUMF

Gabby: No news about trigger, working on getting coincident hits.
Laura: Computer is working, can be accessed through ssh now.
Kate: Wrapping up on the reviews. Drafted timeline for 30 MeV (requested by the gate review committee). Will send out this soon. Also getting James and Joe's drawing signed off. Collimator is set back because the cooling system is not compatible with copper piping. The central material of the collimator needs to be changed. Laura and Ethan are looking at using COMSOL to do some simulation and modeling. Also, register for collaboration meeting! Reservation will be made soon! Invitation letter will also be made soon!
Stephanie: Beam is up but had some stability issue last week. Beam will be off Monday next week.

No updates on the magnetic field map.

December 11, 2024

MIT updates:

New person: Holger Witte, new associate director of Bates taking over from Jim. Jim’s still around.
Scattering chamber being pumped on.
One of spectrometer chambers successfully vacuum tested to 10^-7. Second now being tested.
Hall probe holder design being manufactured at central shop. Accidentally only asked for one, now getting 2nd done.
Joe should be back to do radiation shielding around GEMs shortly
Spoke with Jim about when they would ship. In principle if all goes well with vacuum, could start crating it up next week. Jim skeptical about sending it before Christmas. Kate and Mike think we should if we can.

TRIUMF

Spool piece done for the PMQs! Doug has it for alignment
Might move a trigger counter down to the hall and see that we can read it out upstairs. They’re running beam there
Got yelled at for import/export paperwork. We need to understand this. I do not understand it. Insurance and ownership remain questions. We never got responses on IIA and need to
- Going to be in trouble for compliance if we don’t
- For shipping, insurance is covered until it arrives but not afterwards
- Question is what we have to do: statement that they are happy to have stuff uninsured?
- Richard taking ownership of MOU
Need list of names people want to send here so we can clear them. May as well give most extensive list and downscaling is easy
Update todo list and institutional responsibilities
UBC can’t do welding; no one in Vancouver can do it. Risky thing to do to send it to California or Toronto. We should do it here.

GEMs/Hampton

Ryan finished training and can write work permits, but otherwise no work

SBU

Roger asked for FLUKA data files so we can keep in our repo for future reference. Some level or archaeology but he’ll figure it out
No conclusion on COMSOL or whatever

Agenda for collaboration meeting

Mike asked to add Konstantin to computing/DAQ
Likely 8 am Wednesday meeting with director

December 4, 2024

Kate chairing

Magnetic field mapping

Shaquille was going to go check if the coordinates were correct
Hall probe could have been on an angle
10cm could be 10.5 cm offset which is half a tooling ball. Shaquille could have used center of the fiducial point but edge of the tooling ball.
Doug shows results

MIT other updates

Continuing to work on chambers in preparation for leak checking; should start in next few days
Joe’s working on drawings for magnetic probe holder and shielding
Central machine shop dropping all the parts off for GEM supports today
Want to mount the Hall probes on the front of the spreader bar
- Huge argument amongst MIT people about it
- Decided not to change it
TODO TRIUMF: take spreader bars off and put two new holes in them.
- NOTE: the two spreaders are different so mark them so they go back on the right ones!!!
- Kate received drawings Dec 4. TODO forward to Doug P
Shipping still expected at end of this month but might drag into January

Hampton

No updates
Have not yet ordered new cables

TRIUMF

Mike picked up radiation monitors from downstairs and have given to Clauzi to check data. Did we have any high current runs in the last week? No. Will we in the next week? No. But the week after that probably we will
No other news from e-linac side. Might shoot for 3 days continuous beam delivery next week or the week after
Trigger updates: had mentioned we were having problems with distribution board communication. KO working on it; seems improved. Now waiting on him to finish improving stuff with the calibrations

Collaboration meeting

Kate reminded everyone to register
Doug intending to start at 1 pm on Wednesday and finish by noon on Friday
Concentrating just on issues for installation

Shipping dates and TRIUMF resources:

Ritu and Doug: need really precise timeline in order to prioritise TRIUMF resource usage
Richard: wants everyone to acknowledge that MIT is also short of resources

November 27, 2024

Kate chairing

Collaboration meeting

Agenda: really concentrate on installation and planning.
- Outline all the steps and make sure everything is in place and whatnot.
- For Jan’s group, important that everyone present something in order to make travel reimbursement easier. Put it on Friday maybe?
- Really have to focus on installation and discussion.
Start with integration discussion on Wednesday to give time for discussion and coming back
Attendees:
- SBU: Sid, Win, Jan
- MIT: Doug, Ethan, Richard
- Hampton: Manju, Ryan, Michael
Doug to make suggested schedule we can build off of
Richard proposes: try to schedule meeting with management while we are here.
- Ritu, Nigel, Oliver K
- TODO Kate: Propose it to Oliver K and see if he picks it up.

MIT status update

Jim: converging on the last few items that need design work: probe holder and the shielding/supports. Had some issues with the device for holding the PEEK in place.
Technician working on leak checking the dipole chambers.
Scattering chamber getting welded; should receive next week
Stands all done
In pretty good shape!
Put the PEEK in; can’t get it out. Need to be careful about that when cleaning.
Will ship before Christmas, on order of 2-3 weeks from now.

TRIUMF status update

Magnet field mapping update:
- Thomas: finds it worrying
- Doug: wants to put beam through it and see what happens
- We would like to see simulation result at least to get an idea of what’s going on
- Looks like axes might be warped?
- Missing some parts of the pole tip in the measurement. See if Shaquille can get in there to get a more complete map.
  - Thomas: would like that we understand where this disagreement is coming from
- Richard: can you check divergence, if we have 3D components?
  - Thomas: we should have the data for that, just need to track it down
- Ross: you could use three parameters (delta x, delta y, and a rotation) and see if you can essentially match these with the right axes/stretch
- Setup we’re using is relatively recent and could definitely have problems
- Thomas: shouldn’t treat this as unimportant. Should treat it as important and make sure we understand it accurately.
- Doug H: Laura, send raw data? He can also look at it from his end.
Triggers
- Last week mentioned we lost communication with triggers. Not resolved but KO knows what he needs to do to resolve it.
- Right now, can work with it as long as we keep getting just this one specific error
- Calibrations are just wrong. KO will be helping with that.
- Depressing week for the triggers but there is a plan for fixing it.
- Repeated silicone problems where the silicone wasn’t curing. Looks like we might be able to use optical grease instead, but need to fix the calibrations to confirm it’s OK.

SBU

Mostly working on software/sim so updates mostly in yesterday’s meeting
Win found bug in simulation with single thread mode. Investigating.

November 20, 2024

Jan chairing

TRIUMF

Results from first spectrometer mapping and passed them to Laura
First glance looks reasonable
Resolution: 0.5 cm grid
E-linac news?
- Thought we might have a reason for the discrepancy in the energy measurement between the different dipoles. Got to the bottom of it and it wasn’t that. So still have a discrepancy of about half an MeV depending on how we measure the energy. Don’t yet have an energy more precise than 500 MeV
- Systematic discrepancy; always the same ratio? Maybe
- Have an idea what next to try.
- Mike: anything we could use as a standard candle to calibrate there?
- Richard: if you know the field and the angles we could do it from the magnet settings
- Jan: we could maybe compare elastic with first inelastic? Carbon lines could work?
- But we can try to essentially constrain via experiment
- When we are installing DL the dipole part of the beamline will be open and Thomas could pop a Hall probe in there and re-measure
- Next plan is let the e-linac sit at a few kW for four days. Around 27.5 MeV. Currently testing reliability rather than pushing energy. Have to run for days to check that RF instability stuff is really gone.
- THz radiation working now; scales with charge density in bunches and therefore gives metric on bunch length. Mike: could be useful as a clock? Thomas: might not be usable for that. But we can talk about that offline
Trigger news
- Gabby: on Friday evening there was some kind of power trip on the triggers. No one was touching them. When she got them back online they wouldn’t maintain it. KO diagnosed problem with the distribution board (fixed) and another with the i2c (promised this is being fixed). So less worrying now than it was the last few days
- Problem with lack of discussion/clarity is that if this happens during running we need access to Konstantin, which can be tricky
- Konstantin did promise to train Gabby on some of the Midas stuff though so we can maybe get halfway to supporting ourselves (well, Gabby supporting us!)
- New power supply to come in
Collaboration meeting
- Should anyone stay? Could be some work to do integrating triggers/GEMs/DAQ. Hampton, Ethan, Doug?
- Ryan: Michael might go in January. Ryan won’t.
- Jan could stay and come in Sat/Sun to work on the computers
- Doug volunteers Ethan to deal with GEM readout/DAQ. Ethan can come for the full week and do this for a couple days.
- Did Jan and KO decide on an event numbering scheme?
- Need to get clock from TDC to MPD and use that? FPGA has to provide 40 MHz. Jan thinks it should hopefully work. Mike advises Jan coordinate this with KO (TODO)

MIT update

Going to leak check everything together
Target chamber stand is coming together early next week
Making list of flanges, parts, etc that we need
Still looking to ship before Christmas.
Reminder that we need design for shielding stands so we can try to make it here.
- AD-20 aluminum extrusions. 25 kg of lead can be supported from the yoke. Latticework of aluminum extrusion can support the lead sheets directly

SBU

Win working on simulation; gave brief summary from yesterday
Get the last two documents signed off today - Jan is happy to go ahead

November 13, 2024

Kate chairing

MEG results

“Proton radius all over again”
Doesn’t change anything for us immediately

PRAD X17 folks: had some blinding discussion also a few days ago

They have large acceptance setup where both arms are in same readout
Just held collaboration meeting. Combined experiment for proton radius as well as DP search. Plan is set up everything and stage in course of next year and get ready for data taking at end of next year (Nov 2025) and could run for as long as a year
Jan: clearly need more people, need to run 1200 hours or so. Need people to take shifts. Jan said no. Would be in conflict with himself on all fronts.

Status updates, MIT

Met with Joe and Ernie yesterday. Most things in production. Downstream bellows and upstream bellows/BPM at the contractor company being welded. Prognosis is 2 weeks.
PEEK has been machined, installed, fits. Couldn’t get it out again lol
Received tungsten collimators. Still waiting for exit flange from central machine shop. Once they can get the PEEK out and clean everything, can do a vacuum test. And then would be in a position to ship.
Magnet power supplies passed on to person for shipping
Last thing that needs to be done is Joe needs to finish design of shielding support (around scattering chamber and around GEMs). But both are just doing the design and we are supposed to build this
TODO Doug: get us design as soon as possible so we can figure out where we can get this done
TODO Kate: get this on our todo list

Michael/Hampton

Ryan is at PSI
Lab equipment packed and in storage. Just need to finish some training to get set up.
Have exchanged some thoughts on power supplies, just need to do it now.
Bishoy: can we clarify real dimensions? In Solidworks models the area is bigger…
- Michael thinks Solidworks should be consistent with the DXF (?) files from CERN
- Yesterday they corresponded with Win and sent them the tarball of this. To resend with attachment fixed
- So bigger size is “most accurate and reliable information we have”.
- Difference might be a 1 cm frame/canvas around the foil? Something like that? Could have opening bigger than the active area and that’s what went into the model …
- Joe asked Doug about dimensions of GEMs: not active area but thickness. Doug looked at drawing Michael sent around quite a long time ago, where total thickness of the GEMs is 15 mm including the frame. Michael thinks reality might be 2 mm thicker for 17 mm total.
- That’s going to move the focal plane.
- TODO us: measure and confirm

TRIUMF

Shaquille has started on dipole mapping. Has done pressure tests on them and is set up for actual mapping.
New PMQs: good? Yes. Go ahead.
Trigger updates: Gabby focusing on midterm. Gabby trying out without extra silicone layer and she’ll let us know if we’re continuing with that
Mike gave KO all our cables; went through it yesterday to check everything we need. He’s going to make a TDC cable. Showed him the position of the rack.
Mike moving the cable over to measure the next hole, and we are thinking of putting a detector downstairs
Gabby planning measurement of crazed vs good scintillator, just needs a fully assembled paddle to do that

Gate 2/3 rescheduled review

Jan in Japan first week of December

Collaboration meeting? TODOs:

[Kate] Set up registration site
[Somebody at Stony Brook] Make an Indico with dates on it and email everyone about it

November 6, 2024

Jan chairing

Joe update:

Received all the parts for the target chamber modifications and all the parts for the downstream beamline bellows. Dropped off at Ramsey Welding this afternoon.
2 to 3 week lead time to finish all the welding.
Dipole stands now complete
- Thomas: should check the electromagnetic stray field when the stands come. Doug P: can check
Drawing status: Doug to ask Dan again for a name
Trying to get drawings to shop for GEM/trigger supports

My updates

SAR update
- Need drawings
Thoughts on collaboration meeting dates?
- Those are the best we’re going to get. Let’s do it
Installation dates
- Have to look at gate reviews for a number of other projects and see when things will happen
- Put DL in for end of January as a placeholder but it’s very tentative, and is still a placeholder
- Be ready by end of January
- Gate review for the shutdown - needs to get done
- Talked to Peter Bayliss about project management gates
  - Doug can just add his shutdown gate review template into that agenda and we can do it all at once.
- Job status review in December, and then it can go into the schedule
JLab meeting: looks like 11th is best, can Mike ping the thread to try to get Oliver to converge on this

Have EB meeting soon to plan strategy and set up for meeting

TODO Kate

TRIUMF other

Trigger team: where do we stand on the hut question?
Did a bunch of measurements for cable lengths yesterday. Depending on exactly where we can put a rack, there are 3 chases we could use. C was the shortest, and with a diagonal down to the experiment location was 12.some meters.
- Might not be able to do exactly that, likely need to go about halfway across at ceiling level and then diagonal down. Saves about a meter
- Worst case scenario still around 15 m
- AWG 12 or 14 would likely work. There’s a spool here and we can maybe get hold of it? Otherwise 12 week timeline
  - If we wanted home hardware cable it would be not shielded correctly
I2c and the other cables of Konstantin’s: not too worried about it, can put a raspberry pi downstairs
Hall probes: Doug H bought short cables so power supply/controller whatever has to be downstairs. According to Jim it’s a “small box”.
- Joe hasn’t seen hall probe controllers
- T1-Sys-6 Hall probe system with T1 control system, 6 feet of cable.
- TODO Kate: Confirm cable length with Doug H. Draw size of footprint of box that would shelter this and can we get it anywhere were we can actually connect it with six foot cables?
- Doug checked Hall probe manual: should be easy to extend cable length
- 9.2 Cable lengthThe HP-1 probe includes active electronics that boost the signal from the Hall element and send it to the T-1 in differential form. This permits a relatively long connection which may be helpful for some installations.The standard probe cable is 6 foot (1.8 m) long. To increase the cable length, simply add a good quality 9-way screened cable terminated in a 9-pin DSub male at one end and 9-pin DSub female at the other. The cable should have all nine ways connected pin to pin. This type of cable is readily available pre-made in various lengths. The connection from the extension cable to the probe cable can be secured using 4-40 UNC threaded spacers
- TODO could Doug H look at cables he has and do something with them? Can we get 2x20m cables? Jan says they’re all shorter than that. Email to manufacturer saying what is the ultimate length. Jan will take a look. [Add drawing] TODO Jan: send cable on Amazon to me and Laura
Five ethernet cables from downstairs: one per hall probe, one for the rPi, . Real ethernet cable not fiber. Can also put switch downstairs and run fiber upstairs but it’s another thing that could fail in radiation.
Mike and Joe need to figure out the right part size for the stands

Update on GEMs

No evidence that 15m doesn’t work
They had to move, so work paused.
Cable quality is important. Fancy expensive cables will make a big difference. We should maybe make sure we have new ones
Need low voltage power supplies for the GEMs - do the same thing (4 wire power supply) as for the triggers
TODO Michael and us: figure that out
What voltage do we need? Different from the GEMs so they def need different power supplies
Jan still suggesting 4 wire supplies for everyone
TODO Michael: order new power supplies and cables, test at lab, send up

Concrete hut

Statement would be: experience from JLab and previous experience from Olympus, and tests from Ryan, show we can probably get away with this.
However we can’t guarantee it - what we see in running may not reflect
Doug P: add caveat that we need to put rack on the north side where the cables can be short. That is a demand as part of this
TODO Kate: draft and send around a statement on the hut, resolving the issue as above.

October 30, 2024

Kate chairing

Pipe making

Doug has enough beam pipe, just might need to cut it
Spectrometers: Shaquille was mentioning we have to make up cables
Ernie mentioned headers were at MIT, but we thought they were here? Mike says they were on the magnet when he saw them on Monday … Doug will go take a look
Discussed field map with Ernie: do we do for a current setting, or do we do VI measurement by field we want? Assume we want different field maps at different currents, which is easier to do now … but yes, either set a current and tell field, or set field in the centre of the magnet and check current.
Doug H says it’s up to you on some level what is easiest
Doug P would rather do a full field map
Thomas: thinks we need both. What we want to do is make sure we can align the spectrometers properly without having to realign detectors later, ideally
- Thomas wants to try to minimize chance of having to move GEMs by having a really good measurement of magnet map first.
- So question is what is more important for setting that coordinate to the outside of the magnet.
- Hall probes will be there in the long run but aren’t there now. Which means need B vs I now etc. Knowing BI and mid plane field measurements both would give us what we need
Doug H: what granularity/step size can you take with the mapping? Thomas: couple of steps every gap height (?) Doug P: 1 cm would be fine
Doug H: will send some field values assuming nominal operation at 30 MeV and Doug P will do something with that
250 A is max of power supply; is that what we need in the cables? Ernie said 220 A for the thing he tested. Difference between 200 and 250 A is the next step anyway, so we need to do that. At least 220 in real life too.
Can mysterious cable stash support 250A? Doug P: will look around and see. We had some for M9 and he had some spare when they did the front end of 4North. Might have ends left on a spool. Doug will look.
Will the power supplies fit in the rack we would be adding? Probably 19 inch rack mount.
Thomas would be able to say where we have space, and then we just have to ask Mel if it’s acceptable. Easier to put with other power supplies

Scheduling update

Running beam at the moment, at 30 MeV
Seeing that we will need a month to resolve some of the issues we are having, and some of them are concerning us directly. One is we don’t know the beam energy very precisely. Disagreement up to half an MeV in ways of measuring the beam energy. Need to fix that.
Tested the low energy collimator to get the peak current down for our commissioning. Tested attenuation and it was fine. But only tested it at low energy. At high energy we have to engage license enforcement system and it’s in the same box as the collimator. So can’t currently send high energy and low current. To make that possible, need to complete the implementation and commissioning of the new licensing condition thing. So need to do that.
Bottom line: need to continue running beam at e-linac to the end of December at the very least.
In the new year, cyclotron has to happen first. But we can be put into the schedule.
Doug to discuss with leadership on Friday about shutdown jobs and what we need to do
Still need a final word from Hampton on hut
Aim for decision next week so that we can reschedule gate reviews
Joe update: cutting vacuum pipe; very reasonable quote from welder who can do what they need

TODOs:

Magnet power supplies are 19” rack mount, 24” deep. Should fit in our existing racks
Go identify a location and send Mel a yes/no question

Doug H:

One spot we can position the Hall probe such that it’s between the pole faces. Joe had a way to reach that but he hasn’t designed a bracket that can accomplish that yet. It’s farther down the to do list.
Hall probes are at MIT, just need an attachment. But they haven’t made that.
Have to wait.

Measuring the GEM dimensions: Joe to send request and we will send measurements

October 23, 2024

Kate chairing

MIT update

Magnets expected at TRIUMF today
Have a design for the bellows on the scattering chamber!
- Jim and Joe doing on site meeting at Ramsey Welding tomorrow to discuss whether or not they can do what the design has. Incorporating both bellows that were shipped to them, one on each side of BPM, and modifying conflate.
- With both bellows compressed they have 1/4 inch gap to get the conflat gasket in
- Joe in the process of assembling stands for each component, so far looks good. Should have dipole stands ready shortly; target chamber stand is in process of being welded
Jim put everything in DropBox so it should be ready
Doesn’t include connection to the dump
Need Doug P to look at everything downstream from the bellows and upstream from the dump. Figure out what’s there, does it work? Do the steering coils fit? Etc etc
- TODO Doug P: take a look and get back to Jim
Pack & go includes CAD files for the spool piece with the PMQs on it and Mike can get it into the UBC queue
- TODO Kate: dig out those files for Mike
- TODO Kate: complete order for new PMQs to Sabr, after discussion with Doug
Support stand for GEMs and trigger scintillator: looking good
- What size holes should there be in the T-channel? TODO Joe: check and let us know
Power supplies for the magnets will be delivered this week. Ernie will test at Bates and then ship them.
Do we want everything in a big shipment or piecemeal? Stands, power supplies, PEEK, etc
- Inclined to wait and put it all in one package for less fussing with customs
Power supply specs: do I have them?? Unclear
Installation timeline: need to push ahead with controls, cabling, etc if we want any chance of doing this before Christmas
Doug suspects they are still 4 weeks away from shipping
- Conclusion: this is going to be a shutdown job
- We are not installing this calendar year
SAR update: TRIUMF safety review Nov 4. Most things in good shape

Stony Brook

Very cute 3D printed model DarkLight
If we run Cooker code with Geant loader library it didn’t produce any histograms. Something to do with the multithreading. Need to figure that part out.
- Ethan adds a caveat: this is the first thing he’s found that appears to be wrong, but that’s not a guarantee it’s what the problem is. If we can fix it so we can still run with multithreading that would be best.

Hampton

Almost done with the move, a few heavier things to go tomorrow
Confirmed 10% attenuation in ADC counts relative to 15m cables.
Updated clock phase
More noise, but using longer cables isn’t necessarily a problem
- In clustering, you look for peaks, correct for common mode and pedestal. Look for local maximum to identify possible cluster candidates. So some areas get dark areas …
Mike gives the heads up: might have to put the 2 low voltage power supplies downstairs and just shield with a little bit of local concrete. If we have to do that, could probably put the mini VME crate downstairs still
Jan’s suggestion: 2 wires carrying power. There is voltage drop across them because there’s a lot of current through them. So then you add another 2 wires that go back from your device to the power supply, where the power supply can do remote sensing of the voltage that’s being received, and adjust accordingly
- Mike: the issue is really that we have to put in like 13 V to supply this. Unclear if it can survive this?
- Jan: also just use thicker wires? How much current do we need? Mike: 5A at each of + and -. Jan thinks that should be manageable but needs a power supply that isn’t grounding the negative side (?) Otherwise ground at the detector side will be 6V up

TRIUMF update

Trigger building well on its way. Gabby building the first half of the first arm right now, should be done by tomorrow morning as long as silicone cures.
With the crazing, haven’t found any way to reverse it, but we do have some new scintillators that look really nice. Five really good scintillators; need 16 lol but let’s see
Once this arm is done, Gabby will hook up in good pair vs bad pair and see if we can see tangible difference. And then decide where to go from there.
First two had been in the setup before, could show some crazing from stress?
No change in procedures, just being followed more carefully now

AOB

Joint March & April APS meeting coming up; deadline for abstracts is this week. Consensus was Canadians are not interested but Americans should sort it out. Thinking overview talk from Ryan, sim talk from Win (?)
- Just submit an abstract
- Manju not interested in going, so don’t necessarily have someone to discuss GEMs
- Win to do overview then, Ryan to do GEMs talk?

October 9, 2024

MIT update

Magnets left Bates a few days ago, they are in transit
Will need mapping once they get here; Doug P has room up in the proton hall extension
Stephi signed off on model with gauge valve moved in
Steering coil is tight fit but it fits
On the survey data, which stand was it? We think the main one; figured out now
Jim will be ready to post final models in a few days!
Power supplies? Ernie: needs to call about it. But last time he heard they were meant to come on Sept 16th and were waiting on a part. Said 4 weeks more, so should be basically now

GEMs:

Work at LERF: continually taking data with the 20 m cable. Taking some runs with the new latency value
Organisationally: needed to vacate test stand and leave the lab. Think they can move to an existing location at JLab where other GEMs are being tested, with the tradeoff that they engage in another JLab project. In this case, PRad.
- The way this is being structured is they’d like to accept contributions from satellite groups doing service at JLab
- Will not join as full-blown PRad members and be on the competitive experiment, since X17 search is also a declared goal. Has same kind of conflict of interest issue between Muse and proton radius stuff, so that’s also a challenge
- So tricky in any case. But use of common technology is hopefully an ok area to do this.
- This gives the opportunity for the DAQ upgrade with support.
Timelines: recently talked about timelines and Gantt charts and such. Want everything on site as soon as possible, but experts are there. Envisioning that they maintain GEM setup there a little longer, until end of the year, while efforts can be implemented to put up the final detector staging of one arm at TRIUMF but they’ll complete the second one early next year.
- OK, but need to keep the momentum going.

TRIUMF update

Finally got some RPG input we can use

October 2, 2024

Kate chairing

Stony Brook

Ring clamps printed and in the mail. Sending it to my apartment.
Ethan: running some simulations for Jim regarding GEM detector shielding; takes a while though so it’s just puttering away
Win: nothing beyond what we discussed last time

TRIUMF - triggers

Gabby: keep polishing, keep gluing, etc until they’re all done. Then the scintillator shop will give us old crazed scintillators that we can try to fix with fire etc to see if we can prepare better backups.
Cable lengths: Konstantin away til tomorrow. Mike has a 20 m cable we can use to test i2c as well as 20m twist and flat, so we have the materials for testing (and actually enough shielded twist & flat to do the full distance) so we just need to actually try it out.
- Haven’t tested a 20m twist & flat, but no difference between short and 15m, so won’t be a big deal for that
- I2c is the bigger worry, but KO could put a raspberry pi down by the detector so we just move right away to ethernet. Needs to be shielded but should be easy cause it’s so tiny
- Jan posted overleaf link where we started writing text about the hut question: https://www.overleaf.com/1185154867tzfytwfmsgrq#661dbd
Still need to do
Ordered all the parts we need to assemble the plastic holder

Hampton University

Last week, reported clock phase had to be tuned for the new time delays. Done; Ryan took some cosmics runs and looked at them. Noisier and lower amplitudes than before, and latency also had to be adjusted because the cable length is significant for that. Had to be moved by ~ 50 to 75 nanoseconds. More data to be taken
Also have long cable for i2c, yes? Yes: replaced all 6 long cables with 20m cables. Configuration and readout still works fine. Haven’t tested any gains with the oscilloscope yet; it takes some time.
Also a question about low-voltage supply
- Really need a 4-wire power supply. Don’t have that now, but they are not that hard to get.
- Michael requests source from Jan; Jan will do
- How much current? Couple of amps. For full thing, say 20A total. Jan: that’s a lot.
- Laura: one GEM she has set up is drawing about 2A at 5V but spikes when you turn it on, since it depends on what it’s drawing at the moment
Other caveat: running out of time with the availability of the lab space. This morning tried to ask for another spot they can use but not making a lot of headway. Can move things to Hampton but it’s harder.

TRIUMF - e-linac

Starting to cool down today! Everything seems to be fixed! Wheeeeeee
Question is how the beam will look, but will be 1.5 weeks before we’ll know.
Any update on PMQ studies? Can tell Laura how to do it if it’ll save time.
- Have not done it yet. Laura will be around all day if Thomas wants to follow up with her.

MIT

Just about to ship the box of magnets
- Doug H wrote to Ann and said we are shipping these temporarily to TRIUMF, that MIT will remain the owners, and eventually it will be returned to MIT. Valued at $6500 total. Also told her to talk to MIT insurance and give their true value at about 10x that.
- MIT will insure it. Do not accept insurance from Watchpoint. They are sorting it out.
- Shouldn’t be anything we need to do on our end to make import go smoothly.
Mike shipped bellows - tried to do it on Friday but they were sent on Tuesday in the end thanks to TRIUMF bureaucracy. Seems to have gone by land … not sure why.
Jim showing latest model
- Has camera box on the chamber in the model!! Just need to get distance from target to opening of box and we can pass that on to our diagnostics guy. If we can turn a corner we can get way closer but it seems diagnostics prefers straight line …
  - In straight line, distance to target is about 55 cm. Could gain another 5 to 10 cm by trimming corner of the box.
  - TODO: Stephi to check with Victor
- Downstream end: Doug P heading down to finalise measurements this morning right after meeting. Once everything is totally confirmed, Jim will finish connections and make drawings!! Wooooooooooooo
Question about distribution of labour for spool piece making
- We are still deciding what needs to be done and by whom
- We need up to five spool pieces and need to figure out who is going to make them:
  - Two pieces holding PMQs, otherwise identical
  - Long piece with the BPMs
  - Short simple piece connecting chamber to camera
  - Short piece in between the two long pieces, with bellows - MAY BE REUSEABLE
- Doug P to check what we have already. Will make list of supplies available.

Simulations

Laura running with lead in back of electron arm

September 25, 2024

Jan chairing

MIT

Magnets are almost ready to ship, are being crated. Should ship out Friday or early next week. Will send bill of lading when they have it
Might have solution for bellows. Joe is looking into it. Will have update next week.
Jim has beamline, would like to go through with Doug Preddy just to make sure we don’t need to add bellows or anything. Question on whether the table for the diagnostics box is fixed: yes. EMQs can slide in z, we just have to drill new bolt holes.
Doug P. will get the as-builts for the table and give to Jim.
EMQs may be hanging off table, will have to check.
Mike: have changed to a t-channel on the trigger supports, instead of threaded rods. May require change to frame mount. Joe: will cut into space we have to mount support. Discussion follows, it should be fine? Also some discussion about the HDMI cable holders and frames, discussion being taken offline.

SBU

Jan shows the current model for the retention ring for the PMQs. Can start producing them now.
Stephi asks about material: PLA plastic, insets are brass or stainless steel.
Jan will print a couple and send to TRIUMF so we can see if they work.

TRIUMF

Bad news: scintillators are aging much faster than we thought they would. A lot of crazing.
Jan: saw the same thing in MUSE. From mechanical stress.
Saw fingerprints as well as crazing. Only one end out of four scintillators were bad, but otherwise didn’t affect the timing too much. In the process of producing new paddles.
Temperature in the ehall? Room temp. not extra humid
Polishing material? Possibly aluminum nitrate, but will check tomorrow
Scratches go from left to right, Jan would expect mechanical stress to go other direction
Jan: could try flame polishing them. Wouldn’t try it on something that is still working, but worth a try otherwise.

Hampton

Ryan and Manju at a conference
Taking more cosmics data with existing cables, and are working on comparing with the longer cables
Ryan had some initial results, but had some read out issues, working on getting a good baseline
Should have by end of next week.
Jan: do we really need to 90 degree connector? Haven’t found a long cable with the 90 degree connector on them.
Fans? There should be some airflow over the APV cards and heat sinks on the power regulator chips. JLAB operates with the heat sinks but with no fans. Since we’re building inside a box would maybe be a good idea?
Mike: maybe share setup from JLAB?
Taking discussion offline

September 18, 2024

Back to the bellows discussion

Brief summary thus far: need to get a bellows between last dipole and target chamber
MIT doesn’t have capability to do the welding?
Jim: issue is space. Getting BPM and bellows in there with appropriate flange is proving difficult.
- 10 week lead time with the company they were talking to.
Jan: proposal yesterday is that the ordering and absolute position of BPM and bellows is not important. Could put the bellows in the other order
Also the issue with the bolts directionality. Not easy to drill out. Doug says fixable; Jim says less so.
They were also having the internal weld issue
- Jim: thinks it’d be OK actually. Just do full penetration external weld.
Doug Preddy: has an electron beam welder we could use for doing the fine toothed stuff
Jim will get a drawing to Doug this afternoon and he can talk to his welder and they’ll see
Thomas: 10 weeks is maybe not a big problem. Bear in mind how hard it is to get things done at TRIUMF.

Timeline

Thomas: still not hitting 3 days nonstop. If they want to scale up next year to giving us hundreds of hours of beam time, not yet stable enough to do that. And don’t have enough trained operators. Need to train high energy operators, big chunk of beam time to do this.
Problem is winter shutdown. Shooting for before winter shutdown but we knew if we were to slip we are going to be in trouble there. And we are slipping.
- Or install what we can in the e-hall ahead of time with some testing, and then do the rest as soon as we can.
Haven’t fleshed this out. Need to discuss with beam lines etc.
How do we handle installation?
- When hall is open, we can get cable trays up, pull cables, etc.
- Doug’s big concern is that as of Jan 3rd or whenever, Doug’s team will be mostly on the ISIS beamline install. Is a 6 month job they are trying to do in 4 months, and is the highest priority at the lab.
- If we become a shutdown job we have to have basically an additional gate review where we show status etc.
Shutdowns at TRIUMF have always finished on time. Can we be accepted as a TRIUMF job?
- If we can’t come up with a plan where we can install early in 2025, maybe we should get priority from machine shop.
- Thomas proposes we come up with TRIUMF plan today, and come up with a plan that lets Doug go pester the shop to get us done before the shutdown.
To Jim: does Ancorp have a firm schedule to do this? No, it’s contingent on getting the bellows made. 10 weeks is probably conservative. 90% confident we would have it in 10 weeks.
- If we have one that’s appropriate that saves us 3 or 4 weeks right there.
Argument over who should weld it
- Doug P will take a look for a bellows and we can sort out what happens when
Richard: issue with this bellows & connection, is that all? Then what?
- Won’t install anything til the last minute. Installation will happen in a short amount of time.
- Magnets for sure need work, so pls send them up.
TODO Kate: send email to machine shop to poke about collimator. Can Oliver K help with that?
Michael request: document with dependencies like a Gantt chart? Can do.

Detectors

Thomas wants them really properly aligned before we turn anything on
All detectors need to be electrically isolated from the magnets. To Jim: where we have the final bracket holding the GEMs onto these threaded rods or whatever, are they isolated?
On the distribution board: found a place beside the magnet contact point on the back side of the 36 degree magnet. Is it good?
Thomas: really wants GEMs perfectly aligned. What precision do we need?
- Doug H: issue with GEMs is they need to be in the focal plane. Tolerance 1 mm.

SAR chat

Got results back from Roger & Roxana and they want us to add another region to the modelling.
Agree with Stephi, Ethan et al that the region by the proton beamline is an exclusion area and shouldn’t matter
- Doug P put in extra shielding in the tunnel such that people are in there now when we’re running. That might be why?
- TODO: clarify in text; check in FLUKA
Should be pretty easy to do.
Chat with Ethan this afternoon. 1:30 pm?

Beamline downstream of detector

Shaquille will work on alignment when done BL4N
When we get the drawing from Jim we get it made at UBC
Where does the shielding actually start?
- Aveen: should be in the document from Aveen
- Jim has 225 cm from dipole to shielding; Aveen has an extra 2 cm or so
Doug P can measure crossover point to edges of shielding
This looks really good. Shielding up to date an everything
Add separate bellows with its own flanges?
Spool piece right in between.
TODO us: get 2D drawing for Jim and just move it into the
- Aveen: has dump shielding start, actual dump entrance, actual dump ending. Where is the flange.
- 3D model with the collimator in it
- 2D document number? TEL3054
- Could we get measurements of BPM-bellows assembly that we were looking at earlier? In the photo? EABD. Can Joe get a length measurement of that spool piece? Has 4 inches between 2 faces of conflats. Does that work? TODO check.
2 cm of distance is not enough to save us… maybe adjust stand?

September 11, 2024

TRIUMF

Mike: KO rewritten FPGA code and is relatively happy with it. Using 2 registers in the same channel of the FPGA rather than measuring leading and trailing edge separately. Not sure it made a difference in the res. One end of one counter has wider distribution, took it apart and it looks fine, so not sure what’s happening. Getting ready to put together all eight paddles.
Measured minimum length up on the roof blocks from rack through access hole down to detector is between 16 and 18 m of cable needed. A 20 m cable would work.
10% attenuation in signal along cable. Need efficiency loss per metre. Michael: GEMs have strips, charge blob is a few mm wide so hits a few strips, this introduces redundancy so signal amplitude will vary, efficiency should not be immediately affected. Jan: What goes over the line is the analog charge of the 128 channels, if signal cable is longer may have cross talk between channels. If there is cross talk then he recommends we don’t do it. Michael: will not effect neighbouring strips. Cross talk will pop up elsewhere, can be suppressed in analysis. Jan: Can we talk over 20m with the APVs? Depends on the room, won’t mean anything if we test it at LERF. Jan suggests we go away from the full size hut and then have a smaller hut with shorter cable. Michael: had a similar problem at LERF with the I2C, they had to outsource it. Could have a device closer by to do this that is radiation shielding. Thomas: can we just add shielding around the cable? Jan: more shielding won’t help with length, if there’s noise it depends. Mike: we could test this in the hall if we have beam. Thomas: should have high E beam by the end of the month. Three action items came out of the review, if we have responses to these then we can adjust strategy. These need to be communicated to collaboration once all answers have been collected. Need to understand what we lose if we double the cable length. Jan: Unquantifiable risk, and need something to say that if we go outside and we need something small then we can build it. Also not just the GEMs, hall probes too. Also need to think about grounding. Thomas: Electrical has different grounds on site, should be fine. Still could be a problem, and cannot have connection to beam pipe. Collaboration needs to write down special requests including the grounding and access, extra cable shielding. Michael: has 75m cable that they have run with before and it worked. Going to do some tests, attenuation and cross talk (could try with source).
Michael: got lab space extension. VME crate is defective, won’t turn on. Borrowing one. Do not have a running system right now. Working on it. Jan: priority right now is I2C test, wrap it around something with noise. Need to give minimal size for a small crate in the hall as a fallback. Should try to get upstairs, and if it’s not working we move it downstairs. Mike: would need new cables if we moved. More discussion follows, some offline discission will follow.
Hall probes cannot go in hut, will need a little hut beside the detector. Two sets, one for each spec.

September 4, 2024

Doug chairing

Large number of people currently attending meeting for collab with JLAB for 50 MeV upgrade

MIT

Have magnets at Bates, Ernie has powered them to low current to make sure they work. Will put more current on and measure field to verify that things are good. Need to properly connect current leads to magnets and get water cooling (only to 25 A so far).
Scattering chamber: Waiting to get a quote from Ancorp for modification to upstream beamline going into scattering chamber. Needs to be shortened so we can put bellows in. Otherwise ready.
Vacuum chambers are good to go besides some holes that still need to be drilled.
Power supplies for magnets may be delievered at the beginning of September.

Simulation

See sim meeting notes. Laura gave brief PEEK update (new design has largely mediated the issue of the electrons entering the PEEK and then coming back out and into the GEM, are now seeing more exiting the back of the spectrometer like on the positron side. Adding some lead at the back of the spec arm in G4 to see of this helps).

Hampton

Got new gas bottle so will hook the GEMs back up to ArCO2.
Michael is shopping for angle connectors.

Thomas

Rumour has it they got an adapter for the motor to the He compressor
Doesn't have all the details, but may be able to cool down this week
Installation plans: going to try to install as much as possible before breaking vacuum to give as much time to run beam as possible
Doug: there is a meeting on Friday to review the electronics hut design

Stonybrook

See sim minutes
Doug: did Jan figure out the missing box of computer parts? We’re not sure.
Discussion about power supply for magnets (Ritu and Doug): does it make sense to wait and send everything together? Probably not, but would be good to test the magnets with the power supply will actually use. Ernie is working on getting a more exact time frame from the company (but the current estimate is sometime this month).

August 28, 2024

Jan chairing

MIT

Ernie shares his magnet slides
Chamber can go in while magnet is assembled, with a little wiggle room on the order of 2 mm
Have to look for a decent place to put the hall probe. Has reasonable place to get it in.
- Jim/Doug to comment on where these could go? Sticking down in the back somewhere?
- Jan: can’t we stick them in in the inside bend? Ernie: no, there’s not enough space
- Some debate about whether it’s actually needed or we can do adequately just by monitoring current - think that’ll do since they will be properly field mapped at TRIUMF
Still need things that involve Joe/Jim
- Chamber modification
- Stands for GEMs
- Stands for shielding around the GEMs
Discussion about the distribution board location
- Jan: why can’t you just glue it to the magnet
- Idea seems to be that we can just glue it on somewhere after the fact
Brackets for the GEMs and triggers
- Ernie wants to decouple the questions of holes in the magnet vs stand design. Can Ernie just give some hole positions and Joe works from there? Yes.
- Doug back to the GEMs: make it slideable
- Jim and Joe to discuss directly
- Various discussions of the details, but it seems doable

TRIUMF triggers

Konstantin seeing weird things in the TDC data when studying dark noise
Student co-op terms ending, so probably final assembly to be done by Gabby, Laura, Kate, Mike

Other TRIUMF news

Motor arrived from the company, but the interface is wrong and they don’t know why. Manufacturer seems confused about what they sold us the first time. Cryo working on it to see what can be done.
Follow up on meeting with Oliver and JLab
Comptuters: 9 boxes here, 1 appears to have been sent back.
- B&H seems to have selected different brokers for different packages, which is weird
- TRIUMF people to assemble with Jan on zoom

Sim news

Working on positioning for triggers and stuff
David has determined we will give up on Madgraph
Discussion of G4: does Mike need updated plots?
- Yes please if it’s not a big job. So that would be 10.6 and then applying the weights in the histograms. That should be correct.

Close-out: goodbye to the summer co-ops!

August 21, 2024

Kate chairing

Jan update

Computers still stuck

MIT

Ernie
- Magnet is so beautiful and smooth
- Coils in a separate box, they’ll put it together
- Lovely shade of blue
- Ernie is really happy with them
Jim
- Vacuum chambers: dipole chambers are in and need leak checking
- Working on PEEK; will then pump down and leak check
- Scattering chamber: still going back and forth but it’s still really tricky. Hopefully this gets resolved in the next few days.
- Just sent the stands out for manufacture
- Steerer is the only thing still needed for the model
Question to Doug P:
- Has to be a bellows in this beamline someplace; where does Doug want it?
- Might be worth a separate meeting with Doug involved
Discussion about making the PMQ beam pipe sections
- Doug thinks there’s an advantage to having a single institution do all the beam pipes, rather than doing it here. Risk of there being a mismatch if two different institutions do them
- Jim says that their welder is busy and anyone that is a competent shop should be able to do them. And if we can put a bellows in there then so much the better.
- Clamps: Chris said they had clamps at Bates. Ernie’s design.
- Doug’s worry is just having everything absolutely right.
- Doug will fill in Ernie and Jim on what this needs to be - with set screws etc
- Information to collect and send in advance of integration meeting
  - ID and OD of magnet, along with drawings, beam pipe. Use non-magnetic vernier calipers to measure it
  - Beam pipe - proper measurements, and example
  - PMQ locations for the commissioning design to Jim - TODO Aveen
  - Mike to ask machine shop at UBC - all they basically need to do is weld 2 flanges onto a stainless steel beam pipe. Ernie could call them if need be.
  - Need Doug Preddy for the meeting.
- TODO Kate: measure things in real life

GEMs update

Michael is out of Argon
By end of Sept, have to vacate user lab at LERF. No other space at JLab so have to relocate.
Hopefully final two GEMs will be ready to ship at that time too, so they can send them then
Planning to set something up on campus, have some space there
Expect further cosmic ray tests, varying parameters and finding better working point for HV
Want “quasi-efficiency” maps out of the GEMs they have
Should coordinate coming to TRIUMF for setting things up
Mike: what is the final decision on the cables? 90 degree connectors? Lighter cables? What do we have to install and support?
- Michael worried about adaptors messing up signals, would prefer cables with angles included
- Mike: can you buy and test some of these cables?
- Michael: yes could do that
- Doug: yes. There should be short cables on the order of 2 or 3 feet that connect to the detector in situ and then connect to longer cables outside the shielding box
- Michael might be persuaded to buy something and test this
Doug: buying cables with a 90 degree bend reduces number of connections compared to adaptor or cable

August 14

Jan chairing

Stony Brook

Computers
- Send Jan everything that there is
- 2 servers and 2 clients with 2 monitors each
No news from Win & Bishoy

MIT

Nothing new to report. Missed MIT meeting yesterday, which was Richard and Joe
Expecting magnets and vacuum chambers, but no news yet
Still looking for a solution for the upstream bellows
Joe hasn’t been able to get in touch with Jim but will touch base with him first thing in the morning

TRIUMF

On the new PMQs: Aveen presented everything to Rick yesterday.
- Rick had no major comments except for the extreme sensitivity of the steering on the magnet alignment.
- If middle PMQ is misaligned by even a mm, we can’t compensate for that.
- Need to work on a steering solution for that, as well as work on alignment very precisely for that.
On the review: are we talking about both sets of optics (weak and strong)?
- We can, everything else applies the same way
- Thomas is nervous about what we say to CNSC if we have two different sets of PMQs
- Need to describe the two different sets of PMQs and what their limits are
- Right now, Thomas doesn’t know what’s safe to run with those PMQs and the carbon foil.
- Need to know what is the limit and communicate it to CNSC
- What Ethan would need to do to test this to get Thomas running limits he’s confident in:
  - Implement weaker PMQs in Angela’s catch-all solution positions
  - Then, per energy we want to run at:
    - Adjust EMQ strength
    - Run enough stats to get a decent idea of power limit.
  - Maybe also work out a maximum current with tantalum foil and weaker optics, at whatever representative energy we want to test it at. Annoying though.
- If we know, for example, that we can’t use the Tantalum beam with the weaker PMQs, we need to implement that restriction in Controls so we can’t get away with doing it
  - Usual beam loss monitors would stop it, but it’s “second line of defence” and we would want to not wait til we trip them
  - Jan: need some interlock anyway because we don’t want beam while the target is moving, don’t want full beam power on the scintillator, etc
  - Potentially just add this to existing work request
  - Need to manually switch restrictions on and off as we change the optics
Trigger update (Mike & Gabby)
- Weird result that the copper paddles are performing worse than the others, which is the opposite of how we think it should work.
  - Think the source might be positioned wrong, and/or big impact from having them on the bottom

Simulation/David

Negative results: ran simulation at higher energies but it hasn’t helped much. Stats still super low.
Tried lighter target? Yes. Didn’t help. Did work for Jan back in the day.
Answer from PRad was not helpful

GEMs

The frontend APVs need power, which also feeds the output op amp. That power can come from the MPD or can come from something external. Is it from something external? If so you don’t want two power supplies on the same line [something?]
Look for either jumpers or solder bridges labeled with these two numbers, just make sure they are not connected. Should be “both open already”
Will Ryan do this? Unclear

For tomorrow’s review

Kate to look for a room
Circulate Aveen’s doc when there’s a version she wants people to read

August 7, 2024

Kate chairing

Computing

Go check what’s there

MIT

Magnet is going to be shipped in next day or two
Chambers shipping end of this week
PEEK is in hand, working with Doug to figure that out
Looked at the GEMs and focal points and whatnot, going to make a few modifications to allow the GEMs to sit right on top of the chambers
Bellows we got isn’t going to work so going with an alternate design.

Reviews etc

Optics review likely Thursday
Stephi will check with Shaquille on getting the PMQ measurements done

Stony Brook updates

Nothing other than computers

TRIUMF triggers

A lot of problems we think we can’t fix ourselves, they are coming in on the TDC side. So going to try to extract info from Konstantin.
Weird peak shapes, calibrations don’t seem to be doing what they’re supposed to be doing. Gabby working on copper to non-copper and cable length comparisons, Karm and Angela working on wrapping to assemble the big paddles

TRIUMF other

E-linac still waiting for the motor, expected this week or next week. Then need electrical services to take a look, then install.
Discussing diagnostic screens with Thomas. Can we estimate distance to camera from the model as we have it now?
Gate 2 and 3 planning for 3rd week of September? Doug: that sounds good.

GEMs

Manju: working on optimising ADC threshold. Have taken cosmic runs with varying voltage. Now looking for what is optimal.

July 31, 2024

Kate chairing

Trigger status

Good news, the weird peak shapes in the time difference plots are going away
Angela will work on assembly

Accelerator news

Replacement part is purchased, waiting another 3 weeks for it to arrive
Still working on little things in the low energy section.
Training some new operators at the moment
Some low energy testing
Has anyone heard from Oliver about meeting with JLab people? No

Documentation

Thomas has added basically everything to master commissioning plan, with just a couple points still open. Would like to reference DL SAR
Stephi working on similar minimal modifications to the ARIEL SAR

MIT

Jim’s last day, retirement party for him tomorrow. He may come back, he may not
Joe has been taken over by Ernie to work on Moller
Trying to get Jim to make new design of PEEK
Welding ongoing with upstream piece of beam pipe. Cleaning and vacuum testing to follow
Vacuum chambers for dipoles have been delayed another two weeks
Magnets ready and sitting in NZ
Got the convectron cable, now sitting on Jim’s desk
Saw a preliminary design for shielding around the GEMs when talking with Jim
Questions:
- Thomas: what chamber was vacuum tested? The scattering chamber. Can data be shared with TRIUMF? Bc last time when we pumped down the other target chamber we found that there was a leak. If we can see if we have the same speed to pump down and whatnot it would help us
- Who should we email with questions? Keep emailing Jim.
- Request: please get Jim to use his limited time on finishing beamline connections, not on the PEEK.

Simulation

Story reran with more realistic gun mode and had better results
Win discussing coordinate system for GEM & trigger with Laura. Gabby also sent over some files for signal shapes

The carnet

Wait and hope Queenie fixes it, and otherwise poke Barry next week

July 24, 2024

Jan chairing

MIT

Air freighting the magnets from NZ. No date yet, but hope for next week.
Vacuum chambers inside the spec had two week delay, but should be here next week too
After they get here can do the vacuum tests after they are fit in the magnets
Trial powering of the magnets and measure the field with Hall probe but no field map
Have to drill some holes in the magnets at Bates, will take a couple weeks but will then ship to TRIUMF for field mapping
Scattering chamber is at MIT campus, macine shop is cutting off upstream port at correct length, will then go back to Bates where bellows and flange will be welded to upstream portion.
Then will clean it and pump down, leak check and send to TRIUMF.
Sometime in September should have everything at TRIUMF.
Final form of the PEEK still outstanding, design that was best in simulation doesn’t work structurally, Laura and MIT are iterating can maybe do a little better.
Jim is retiring soon

Angela

See slides on sim github
Is testing setups for C with the target out to make sure the setups are still good for the beamline folks
They all work, just have to change the EMQ values, which is fine
The 50 MeV Ta works fine as well
Attempted to optimize the lower energy Ta, but they don’t work. This is expected, but was worth a try
Now is working on the 2 um Carbon target
Doug: have we ordered the PMQs? Laura: not yet, Aveen’s note is still under internal review

Mike

Tried 8 scintillator setup last week
Strange behaviour in ADC phases on some channels
Investigating whether there are problems, don’t think it’s software as it’s duplicated. Might be something on the FPGA. KO is looking into it.
Crossed paddles so we had coinc between top and bottom 4 run over the weekend
Hopefully by next week might have more updates

David

See sim meeting minutes from yesterday
Since yesterday, tried downloading the nightly as it has says it has integration of the ISR in HI mode
Still giving the same error as before
Is now writing Jesse Thaler an email

Ethan

Working on the SAR with Kate and Stephi
See sim meeting minutes from yesterday

Laura

PEEK discussion: Jan is concerned about the positron arm rate
Solid PEEK was by far doing to best, tried everything I tried in the electron arm on the positron side, so lowering won’t help
Doug wants to check that the magnetic field is correct and height where the solid PEEK starts in the G4 sim (0.2 m in Doug’s code, 0 is at beam height)

Ross

New paper on the arXiv for muon g-2 agreement

Ryan

Probing the noise on the GEMs for the ADC threshold. Can probably go a bit higher, but investigating
Cosmic data with varying voltage on the top GEM to test this
Question to Laura: did you fix the issues you were having?
Laura: no. Power outage caused crate to power down and has been behaving weirdly, in particular MIDAS start run button not working. Will continue to investigate today.

July 3, 2024

Kate chairing

Collaboration meeting.

No visa for Sid, Manju
Figure out where Connor is now and go poke her for Ethan

Brief round table

SBU

Re Doug’s numbers: count rates seem right but scattering momenta seem off. To discuss
Win upgraded visualization to QT6 and G4 is still working on support. So right now when you pick the colour for the objects, it doesn’t work right if it’s transparent.
- Could go back to v5 but it’s not really supported anymore
- Should be not a problem as long as you can turn off the visualisation of the magnets when we need to see what’s going on inside

TRIUMF

Laura to test new PEEK
Triggers: up and down. Had a trigger made with a copper plate installed. Temperature control was going well
Setup emulating positron and electron arm. Moving some around the other day and found that a lot of the light guides were broken off. Maybe just broken because they’ve been unplugged and plugged in a lot, maybe because the copper is heavier? Long story short, we need to rebuild one of the paddles.
- Does explain the weird data coming out of channels 7 & 8
Only main problem in the data is that going back to the longer cable messed up the peak shapes again.
If we do use this copper plate, and bring it out the bottom, right now we have a 2 cm foot on the bracket holding the triggers. If we bring the copper plate out the bottom we add another 3 to 5 mm. We would want to check the effect on the solid angle of acceptance.
- Test 2 vs 2.5 cm above GEM plane, and in terms of x-y location, aim to collect the densest area of tracks
- Win to do this :)
Still don’t have a design for the support structure. Need to figure out whether it’s Joe or Philip who wants to do that.
- Mike thinks Philip is doing the package for the triggers, and then Joe will do the overall supports that hold it in place along with the gems. Need to figure out order of operations on that.
Beam optics: design essentially done, now just deciding on approval process to order next magnets.

Hampton updates

Ryan: started taking cosmics with the 2-GEM stand
Ryan can add us to the git we’re using if we give him our GitHub usernames
We can try to get our software updated to newest version by Monday
Kate & Laura to get it back on the gas tomorrow
Ryan: once we get that together, we can try to read pedestals before we try to set up a trigger
- Laura: had that much set up with the software that was on the crate when we got it, so that seems OK, but we should retry with new code
Front-end code? Using what was on the computer that we got. Is this also something we could update via Git? No.
Jan trying to buy a server, not sure if it will have arrived by the collaboration meeting (probably not) but we could move to network boot and get rid of compact flash card
- Set up to daq17 now, so it should be easy
- Jan can do this while he’s here, did it recently at MUSE

Doug’s slides

Carbon rates harmless
- Have to see what the GEMs can take to see exactly how high in current you’d want to go
- Jan points out it’s 100% dead time so we’d take the same rate on both of them. DAQ rate probably 2 or 3 kHz so we can’t take data faster than that on either side. Would take new electronics to get the rate up to 10 or so, and we won’t have those.
- Ethan: question also is whether you can distinguish between hits. MHz we were discussing was whether the GEMs could discern individual hits from each other. But that’s a higher rate than the readout rate.
Likely unit error making the scattering momenta look so low
- This would remove differences between C and Ta
- Any current low enough to reduce the rates in the GEMs to around 1 to 2 kHz is good; doesn’t matter exactly what the current is
In principle nothing wrong with doing it with carbon except the scattered energy being lower (but it should go away)
Jan: would like to see it with both at highest energy anyway
What is uncertainty in beam energy? @ Stephi?
- Uncertainty at 30 MeV is about 500 keV, so more than a percent. Has to do with how we calculate beam energy from our dipoles. This depends which magnet we use for measuring beam energy. We have a small discrepancy between the different magnets, but we use one of them every time. So we have systematic errors that are not included in the beam energy display. So Stephi thinks it’s actually about half an MeV even if we don’t show that. Variation in the display is less than that.
- That’s a study we’ll want to do
- When they quote beam energy, it’s kinetic energy not total energy
- If we wanted currents down to the nA level, is that’s possible?
  - Stephi: can’t diagnose it, so can’t tell if we’re there. This was never meant to run that low
  - How low can we measure? About 5 to 10 microAmps. Faraday cup can go to 1 to 5 microAmps.
  - Wouldn’t hurt the machine to try to run lower, but could hurt us maybe, if it’s too high rates for the GEMs?
  - Can we get a rate from the triggers? Yep, we’ll have an analog output that we just feed into scalers.
  - So we could measure that and just wing it, even if the rate is a bit unstable.
  - If current drops away that’s not a problem. If it suddenly jumps up to microamps that might be a problem. So kind of depends on how stable the current is.

June 26, 2024

Jan chairing

MIT update

Vacuum chambers expected mid July
Ernie still pushing on magnets, hoping for news by collaboration meeting
Scattering chamber is under vacuum and doing well
Leak in one of the windows. Just a blank, not the permanent one, so not overly concerning
Discussion of which port needs to be optical
- We want the one that is facing inwards to the room to be optical
Should figure out the infrared camera we want to use
- Can we get away with normal camera with infrared filter?
The carnet: evidently the person holding the carnet has to go to the customs office and deal with it

TRIUMF

Poking electrical group about moving us up priority
No news on collimator yet
Small amount of mu metal enough to shield PMQs
- Hopefully this resolves design enough that we can move forward
Aveen sent optics stuff to Ethan and he has a preliminary run on that
- Generally overall features look quite similar between the two
Now Aveen working on adding in scattering angles for different energies
Trigger news
- Things are going well!
- Code completely overhauled
- Two new paddles, so can really start ramping up the testing
- Testing addition of copper plate on the back of pre-amp board, which is dropping temperatures by ~ 5 degrees C
- 2 to 2.some-ish cm question?
- In the model we have 1.5 cm right now
- Could look to GEANT to see the hit distribution at 2 vs 2.5 cm above the GEM? [TODO see if Win can do this]
  - Looked at some studies from Doug and from Chenxi/Cameron/Kate. Should potentially get something with more quantitative measures of loss
- Holder design is nominally there - could Doug share it with us offline?
- Send updated drawing to the team? Not sure it is the right time for that, might waste their time when it isn’t all set
DAQ news
- With 8 set up bars, now able to measure one full set of scintillators for one arm. Doing some readout tests for that this week.
GEMs: waiting to fire them up before the collaboration meeting

SBU

Might be receiving some computer parts at TRIUMF in the next couple weeks

Hampton

Set up the 2-GEM stand and cabled up all the electronics. Can communicate with both sets of APVs; high voltage is stable. Ryan modified the front end code to read out pedestals from both GEMs. Will put it on argon and lower the top GEM to take some cosmic data
Discussion about possibly adding connectors to the GEM HV - maybe discuss at collaboration meeting?

Do we want to put in any abstracts to DNP?

Deadline July 8
People who want to do something, send around abstracts, and let’s see where we are next Wednesday

June 19, 2024

Meeting cancelled

June 12, 2024

Kate chairing

List of what we want to run with for accelerator div

Targets
- 1 micron carbon
- 1 micron tantalum
- The screen
Beam energy
- Enormous argument about energies
- Jan: really just need to test at 2 energies that are some distance apart
- Jan: if we put in the magnets like we need them for 30 MeV, what is lowest we can go? 27 with tantalum
- Thomas: problem here is that we had no clear project requirements.
- Jan: what does 27 mean? Nominal current, 1 micron Tantalum. But it doesn’t scale very well. If we go to an energy under 20 MeV you send 3/4 of the energy in the pipe.
  - Evaluate with carbon and lower current and see how it does.
  - Time to collect requirements, and then we try to be as close as possible to the requirements
- Must write requirements. This is a must, this is a good-to-have, this is a dream. Then we compare how we can do it.
  - Clarifications: we can now go to lower currents
  - Want to run at a lower energy with Ta? C?
  - Issue with lower energy is that we lose most of it, and can only afford to lose a few watts, so we could then only run at a few watts. - TODO Doug H: write page with this.

GEMs

Stripe in same place with 2nd gem. Thinks it’s more of a daq error than a mapping error
Mapping is by APV card, repeating, and would turn up on both axes, so that isn’t it
Goal is a pair of gems soon

MIT

Testing the window material. Kapton seems to be a safety factor 4. Also testing aluminum. Kapton deformed significantly, so point at which they pass through is about a cm lower than where the window is. So that’s an extra cm of multiple scattering in air.
Still waiting for special bellows but proceeding with vacuum tests

June 5th

General news

Spreadsheet of responsibilities from integration meeting; will be saved somewhere central
Ready for payment for collaboration meeting attendance; will post and circulate

MIT

Bellows should be ready to go by end of June/early July
Lid for chamber in progress
Doug has the windows
So basically have everything in hand for scattering chamber. Still need magnets for spool piece etc.
Useful for someone from TRIUMF to come down there to look at things? And be part of vacuum testing and whatnot?
- Could float the idea to Doug P

Hampton

Update from Ryan: taking a cosmic run; only see one vertical streak now. But like before, don’t populate the full active area. Looks to be in the same y position.
- This is the second chamber
- So it might not be a chamber problem, if it’s in the same position
Michael started to review the readout board schematic again and seeing what might be going on
Ryan feels like we would see this in more places if it was a readout board design issue
Also tried probing the connectivity from strips on the readout board to socket output and didn’t find any problems. So doesn’t seem like a soldering problem of individual channels

SBU

Updates next week. Jan and Ethan still away

TRIUMF

Numbers to Aveen: do we have what we need?
- Some ambiguity on box locations?
- Exact location?
Lots and lots of discussion.
Everyone to follow up together

Thomas wants Kate to email Sabr right now about whether the magnet matrix can be made with something magnetic

Doug: would also reduce field of permanent magnets, no?
Thomas: yes they would have to account for that in the model
Doug thinks it would be easier to put a couple layers of mu metal; Thomas does not
TODO Kate: email and ask

May 29, 2024

Followup on location definition & optics

Joe received; Jim not online
Asked Doug for model including dump. He’ll take a look and see if he can find something better
Doug H: can we take off the concrete shielding?
- Yes but it’s annoying
Discussing how to get the files to send to Joe
Location of target and target chamber relative to dipole to flow from MIT to Aveen; locations of downstream items to be set by Aveen and to propagate back to MIT

Follow up on PEEK?

Mostly covered it yesterday
Positron arm is as good as it gets
- Solid PEEK is 41 kHz that cause a trigger
- The ones that are triggering are usually not the ones that have gone through the fringe field outside the chamber, so we don’t have to worry about it
Joe redoing PEEK design? Yes.

Collaboration meeting

Post fees and link on Indico

MIT

Jim putting together scattering chamber to leak check it
Joe says one spool piece needs to be made; sent to shop this morning
Locations: Joe can get these to Aveen tomorrow

Hampton

Ryan and Manju started initial commissioning of 2nd gem. See some cosmics.
Yesterday, shipped four defective GEMs to CERN. They will investigate and come up with a plan.
Considering to have Ryan and/or Manju work on repairs too if need be
Michael thinks the 1 week extension here for collaboration meeting is a bit wasted.
Mike: wants them to do knowledge transfer to Laura, and thinks an extra day could be useful
Michael: beyond single GEM plane commissioning, Michael also wants to establish two-GEM readout chain. And then the procedure for that will be established and could be passed to Laura.
So Michael agrees that a consultatory day or two would be useful but not much beyond that.
Doug:
- Himself and Ethan will both come on Sunday before the collaboration meeting, giving Monday and Tuesday to come to TRIUMF and work on stuff
- Possibly by sometime in July the scattering chamber will be shipped to TRIUMF (Kate points out some bottlenecks)
TODO: Carnet expiring for the two GEMs

SBU

Is busy with Muse

TRIUMF

Trigger status: Gabby. Nothing super huge, working on position resolution studies. Not down to 3 cm, but could at least tell which side of the trigger, maybe down to thirds if all goes well
Run into part shortages to put together next unit. Screws and such.
Q to Doug: when can we actually build this thing? Depends on when the e-linac will be closed.
- Thomas: any day would work
Mike sent size of room to Doug H and Michael
2 VME crates (well, 1 VME and one VXS but not before next year)??
Doug H to Thomas: what are the energies and currents we will have available?
- Energy: depends on whether or not the darklight target is in, and would depend on optics design.
- More specific answer after the meeting.
- Currents: absolute limit is the 10kW. For low current:
  - Tried low energy collimator and it works, so we can reduce by 1 to 2 orders of magnitude
  - Also have much more stable gun now so it’s able to go a lot lower.
  - Combining these, can make it almost as arbitrarily low as we want
Discussed that Angela is looking for low energy optics possibilities that we could do in a first phase.
- 2 phase solution would then allow for that

May 15th & 22nd, 2024:

Chaired by Jan

If anyone has minutes please post!

May 8, 2024

Chairing today: Kate

Thank you Ross for PP-EEC talk!

TRIUMF integration

Collimator weirdness currently trying to resolve

Need to request installation person power

Need to decide how many days we need
TODO Kate: Talk with Oliver and Thomas about what we should be doing to make this plan converge
Commissioning is different if installation is in two phases
Doug will handle commissioning plan

Richard:

Wants a document amongst the collaboration first
Just write down what institution will do what
Will help MIT to justify what they’re doing to DOE

Three documents total:

1. what are our expectations of each other?
- Each group should summarise what they have contributed, what they will contribute, and their estimate of person power
- Each group send me 1 page and we’ll put them together into document 1. Not legal, just internal
1. one page MOU
1. inter-institutional equipment loan (based on TRIUMF stuff)

MIT

Custom bellows that they should be able to install on the chamber when they get it
Chamber shipped yesterday
Just want to confirm it’s exactly what they think it is
Should be able to confirm distance number by this time next week. Looking at 1 to 1.5 inches. Jim will confirm next week.
TODO Kate: go down and take photos of how nuts/screws/flange are attached just downstream from dipole on the corner
Is that a fixed flange as opposed to a rotatable flange
- Rotateable will have a space behind it so it can rotate on the knife edge.
- If I take a picture Jim can tell us
Doug received drawings for mounting plates for trigger scintillators. Send to Joe and Jim
Still need to discuss supports for GEMs. Michael had some input. But he is likely out of luck for what he wants. Potentially need to have a meeting to explain it to him?
- Ryan will talk to him about it

Hampton

Ryan swapped one of the five backplanes yesterday to try to fix issues with something not responding. Took a cosmic run.
- He noticed some of the connections to the backplane didn’t look secure, which he has hopefully fixed
- Michael had worried that this was an issue with the readout board but Ryan thinks that’s not the case

Stony Brook

Win has done good work on trigger sim
Going to work on PEEK shape tests in Fusion

TRIUMF detector side

Silicone issue is fixed. Found working ratio. Third setup ready to go. Nicolas is preparing another one.

May 1, 2024

Chairing today: Doug/Jan/Ross

Ross's PP-EEC draft slides and screencaps of shielding discussion posted on Indico page here: https://indico.mit.edu/event/940/

MIT:

Follow up to bellows discussion from previous weeks: moving the whole experiment 7-8cm isn't possible as stands for magents and beam diagnostics components upstream of the beam dump interfere.
Have around 4cm of motion possible upstream of beam dump. Will cut off BPM upstream of the scattering chamber and change this section to include a bellows and shorten it as much as possible. Some combination of this beam pipe and moving the components upstream of the beam dump should get us there.
Jim will work out solution for next week.
Scattering chamber will be delivered by May 7th and will have design for the shielding soon.
Stands/supports for the GEMs and trigger scintillators:
- Mike: don't have a specific design for the trigger supports yet.
- Will exchange some dimensions/drawings offline and MIT can design.
- Will also design something for the distribution board.
- Michael: question regarding the GEM spacing. +/- 5mm of vertical adjustment, tilt will also need to be adjustable? 1 deg?
- Long discussion about whether to have individual components be removable or have as one big piece. Mainly concerns regarding the GEM cabling being accessible without removing the whole setup/lead shielding. Schedule a separate meeting in order to discuss this in detail. Some images at https://indico.mit.edu/event/940/attachments/1151/1965/shielding%20discussion%20screencaps.pdf
No vacuum chamber delivery dates yet.
Ernie has been in touch with Buckley working on timeline.

TRIUMF:

Gabby: silicone problems, stopped curing
HyperK is making a big batch later this week and we'll see if this fixes the problem. Could be a mixture measurement issue due to the small batches that we make.
Cures on the desk but not in the setup.

Stonybrook:

Win: finishing up getting the trigger digitization and basic analysis code into cooker. Some things will need to be tuned based on the real setup, will need to discuss with the trigger experts.

Hampton:

Ryan and Manju have continued data taking, mapping is mostly figured out.
Some channels on the APVs not responding.
Tried swapping APV positions, swapped patch panel, but issue persisted.
Going to try swapping backplane and see if issue persists.

Doug: beam energies?

Steffi: will have to fun simulations
Range between 20 MeV and 30 MeV
Can't handle 10 MeV due to PMQs
With different configuration of PMQs would it be possible to go lower? Thomas: Don't really want to break vacuum to install alternative PMQs, runs risk of dust contamination that would be deterimental to operations.

April 24, 2024

Chairing today: Kate

Discussion on the experiment location and bellows problems

Decision is to slide it downstream
We will use the existing little bellows spool piece
Aveen will update optics and pass locations of everything along to Joe
Joe will put everything in the model and return 2D drawings to TRIUMF
- Stephi can call him to go through implementation
Agreement with Richard that once this is done and we have everything in the model, we will have a proper design review with the experiment and the lab to check we aren’t missing anything else
Flange to the bellows is 8 screws

Further MIT updates

Joe looking at target ladder and maybe needs to come down a little farther
- Should work out the range of motion and maybe add a spacer
Message from Amcormp regarding feet on the chamber; working on it

Stony Brook update

Simulation side: some discussion between Aveen and Ethan on beam optics. Win’s working on trigger scintillator simulations.

Hampton/GEMs

Not too much to report this week. Ryan busy with MUSE work fest, Manju is taking shifts at JLab.
Recent work on mapping issue: looks like a different mapping involved from ordering of pins of connector to strips. Looks like it’s not in the straight sequence it looks like. JLab folks have a similar board in MUSE; looking at their code.
Granularity mostly gone but uniformity not certain at this point.
Taking more data and working on it. Taking a cosmic run last week.

TRIUMF: trigger updates

Ben & Gabby taking some source data for position resolution
Working with Hyper-K group to try to get non-expired silicone to use
Still trying to figure out where the source went
Distribution board location
- Potentially asymmetric but with equal cables
- Want some angled walls for the shielding
- TODO Kate: send distribution board model to Joe

April 17, 2024

Chairing today: Jan

MIT update

Expecting the scattering chamber up from Florida later this week
When that arrives, will start assembly & vacuum test
Integration meeting went well. Doug will make a list of salient points to send around.
Actual position of the experiment: it is defined, we need to state where it is relative to something that we are confident in.
- Distance is from exit of dipole
- Going to send the info to Bates, and then they will send a new model back to us
- Positioning of magnets is established; now adding things like steerers.
Start with emails and move on to a meeting if need be

TRIUMF

Not really any news from trigger side. Building a third setup to check results of third setup; some issues with silicone curing
No news in last week from integration or e-linac
MainzGen help:
- Should always have many events, even if the cross section is still tiny.
- Positron side could be where problem is coming from?
- TODO Kate: look through all the plots with Sarah again

Hampton

Ryan: made some progress with mapping; granularity weirdness is gone
Used readout code from UVA
- Once you get the mapping right, the readout board is the same.

SBU

Pull request for resolution merged

April 10, 2024

Chairing today: Jan

MIT

Signed off on drawings
Working with Buckley on timeline
Assuming that TRIUMF will do cabling
- TODO Kate: talk to electrical
Jan will do the programming to get power supplies controlled by EPICS
TODO Kate and everyone: need to get correct drawings to Joe. Why did this not come from Chris?
- Kate has sent drawings to everyone relevant

Trigger news

Ben working on preparing another paddle system, Gabby is improving timing resolution calculations
Accelerator news: almost got layout done

Hampton

Still working on the latching, in touch with some relevant experts

April 3, 2024

Chairing today: Kate

Scheduling & first phase installation

Think Stephi gave update last week but that it was possibly hard to hear her audio
Basically: TRIUMF is going to help us but they are not going to green light installation until they have documentation in hand.
Set up regular (2 weekly) integration meeting
- Stephi, Jan, me, Doug H, Doug P, Ernie, Jim
Ethan: Rock said Max (?) would help us write the safety report

Funding

Summer 2026 as a decent guess for when Phase 2 might start? We think so
Michael negotiated renewal with Gulshan who is giving increase for electronics. For damaged GEMs, Michael has a repair quote and Gulshan will pay for that too.

Collaboration meeting

MIT has some left over funding
Jan prefers not to pay for alcohol
Kate to post experiment number on Indico and circulate it
Kate TODO make sure I actually booked auditorium

FLUKA/background rates

Shielded hut: don’t include in safety report specifically.
Does need to be in the model, though
Ethan shared update on shielding ordering
- Would still be really nice to know what the EM quads can handle
- Doug P will try to track down the studies by Marco
Shielding
- Can Jim do the design?
- Then we can machine it
Doug P thinks we can actually machine it ourselves
Agreement: MIT makes design, TRIUMF makes shielding

Beamline design

Aveen got stray field info from Xiaqing. It’s larger than it was before but they aren’t incredibly worried because it’s still smaller than what the steerers can handle. “Not the best but not the most concerning”
Needs to add this to Transoptr to really confirm

MIT updates

No particular news. Expect scattering chamber in the next weeks and chambers for the dipoles in May. Will start assembly of the vacuum system after that.
TODO: confirm whether we want them to make beam pipe pieces with PMQs on them. They have time at Bates to do this if we send them PMQs and right materials they can do it.
- Two phase installation: how do we turn on?
Need co-op student to look at optics for low energy running

Stony Brook updates

Win has pushed update to get trigger working for multithreading

Hampton & the GEMs

Worked on mapping of APV channels to strips. Seems to be different for these GEMs. Talking also with SPS at JLab. Ongoing work.
- APV mapping but then also from connector to strips, which depends on the GEM
“Work, but not a problem”
Big picture: doing this now because we were hoping to measure efficiencies. Quantity that would describe this most closely is how often you have one event over nothing, in case of source triggered run, and we never saw efficiencies above 50%. Looks like clusters were fractured, which seems like a mapping issue.

TRIUMF trigger news

Two matching paddles and going to do a few runs with them to see if the data looks as expected.
Have a time of flight run going on now with 15 cm gap

March 20, 2024

Doug/MIT

Everything is fully ordered. Jim or Ernie can comment on delivery
Magnet: Buckley has a design engineer assigned to it, they have the PO in hand, etc. Iterating to try to minimise machining time there.
Jim, Joe, and Doug went over the shielding requirements. Related Ethan’s inch of lead and poly around the chamber. Leaves just a cm of lead around the GEMs, and it can be just L shaped. Seem OK with it.
- Joe is busy with another project now and won’t get to it til April
- Stands have to support scattering chamber plus lead. Rearranging.
- TODOs MIT: finish figuring out what you want the stands to look like
- TODO think about cutting away lead
- TODO Kate and Mike: Look into getting lead shielding made
- TODO Kate and Mike: Look into getting stands welded
Stand design also pretty simple but we might need to get it done here
Richard found 3 cavities at JLab. JLab would welcome scientific collaboration.
- TODO Kate: follow up with OK next week to see his thoughts and if he replied to Andre

Beam optics

Laura and Aveen working on this last week. Found a bug in C code that they corrected but the improvement was minimal.
What Aveen is waiting on now is that Stephi and her need to work out where the diagnostic elements are going to go
Need to be sure everything fits and then they can send off the final optics
Ethan: what’s going to be on the beamline?
- Aveen: before we started FLUKA there were diagnostic elements integrated.
- 2 BPMs, diagnostic box with fast wire scanner, steerers etc.
Just got updated field along beam axis from Xiaxing and going to check that too, but should be OK
Degree of focusing at 29: Thomas did not express an objection
OK from 27 to 31. Aveen will add 32
Massive over-focusing at 10 or 20 without target.
- Aveen has a list somewhere
Doug: could do carbon targets first, with just thin windows on the exit ports and use sodium iodide detectors to start measuring elastic and inelastic scattering from carbon.
Ernie has seen, and has in his files, adjustable PMQs.
- TODO: can Sabr make one that’s variable? Bob Lown would know. Ernie’s never seen one in person
- https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=2295e15a6b739ed2687d77c497c93363d3b3dedb
Aveen:
- Finish study with high power.
How do we commission this experiment? Order of what we do, targets, experiments?
TODO Kate: give co-op student to Aveen

GEMs

Manju showing some diagrams of latching mechanism
Needs discussion with Ryan et al

Ben on the triggers

Mylar looks better than Tedlar. Ben is making a third setup so we can compare mylar to mylar. Looking at switching around TDC cables to see whether behaviour follows cables or follows the physical setup.
Know we get more pulse height from mylar, and the timing resolution is partly determined by rise time.
Mike: why do we need a second one?

March 13, 2024

Chairing today: Kate

MIT:

Ernie: purchase order finally placed. Delivery time in quote is standard delivery time: can potentially be updated.
Communicating tolerances for outgoing pipe: Ernie will check with Chris and Amcorp (?) about what was communicated.
MIT actually already has a design for the clamps.
- Loop Ernie in on magnet discussion - he prefers clamps because you can’t squish the magnet casing
- MIT can make them; easy
- TODO Kate: contact Doug P and make sure he is OK with Ernie’s suggestion
List of hardware
Stephi will be in touch about diagnostics and what is where
Richard: chatted with head of accelerator at JLab and they have spare cavities.
- TODO Oliver: reply and/or follow up to see what we can get

Space for computers:

Only space where there is some A/C is the old e-linac room
For DAQ we want at least a GB or maybe a 10 GB private network
- Essentially this limits things a lot more - basically want an ethernet cable
TODO Mike: ask Konstantin to contact Jan about DAQ network
- Konstantin will know about what spot is OK for temperature
Stephi: if we want to use old e-linac control room, which is air conditioned, we need to talk with Kathleen
- Reminder that some options we discussed were either old e-linac control room or spare office over in proton hall

CSNC:

Need to update ARIEL SAR
Need standalone DL safety report
K&S will talk with TRIUMF people in two weeks to sort out exactly what we need to change

Trigger:

Talking about cooling: Nicolas might be able to replace spacer with copper plate for better cooling. Doing temperature measurements now.
- Room temperature for 4 boards without cooling: Ben can do tomorrow

Hampton:

Manju & Ryan finished taking some of the mapping runs. In parallel, trying to decode these with the Muse master branch. Had to copy some code over but it worked. Still see the strange pixelation effect - working on getting rid of it.

Collaboration meeting in July:

Assuming we’re also going to be doing some installation work around the same time
Work permit for Ethan?
TODO Kate: ask Maxine about getting work permit for Ethan
TODO Kate: ask Maxine for letters of invitation for everyone, once attendees confirmed (later)

March 6, 2024

Chairing today: Jan

Slides posted on Indico page here: https://indico.mit.edu/event/932/

MIT:

Waiting on statements about when things will be delivered
Hall probe looks like it makes things super easy because it has its own EPICS server
Mike: has the purchase order escaped from MIT bureaucracy?
- Yes; now waiting for a reply from Buckley
Ethan maintaining public facing website: https://darklightatariel.mit.edu/
Joe to come back to drawings in the next week or two
Drawings here https://www.dropbox.com/scl/fo/iuufqqevskmgk00kz6sc2/h?rlkey=7repp8r3kv7f4os79vaiuxzs5&dl=0 are fairly recent - from Joe end of January

Hampton

Ryan showed very nice talk - TODO get slides to upload to Indico
- Discussing latency in triggering read-out for the GEMs
- Plot of efficiency is in %, so 9% is sort of peak achievable there at the moment
Some discussion on interpretations and next steps

TRIUMF

Trigger
- Trigger update from Ben discussing cross-talk in twist and flat
- Mike would like to see the individual times with a time difference versus width
- Should be able to show time walk corrected versions next week
- Long discussion about to what extent geometry is affecting shapes in the results
- Conclusion to redo studies with
Beam optics
- Aveen and Laura converging
  - Good enough for magnet purchasing
  - Will freeze the strengths and positions now, and document (beam optics design note)
  - KP will review physical structure of the magnets next week then place order.

Bishoy update

Finalising MainzGen integration into Cooker
Will then organise its output into G4
Wants to encourage everyone to start using merged version through Cooker whenever we use this. Good way to try out the changes.

February 28, 2024

Chairing today: Kate

Collaboration meeting dates discussion:

Everyone who has answered so far is happy with July 10 or July 17
If you do NOT like those dates, go answer the newdle!! Otherwise we will fix the meeting for one of them.
If we have the collaboration meeting in July, we would anticipate having vacuum system at TRIUMF at that time. We could be in a position to install, if everything else comes together.

Two phase installation discussion.

Stephi has not had a chance to discuss with people yet
Thomas was not opposed to two phases
Doug Preddy and Marco Marchetto were going to reach out to Buckley and see if the date could be advanced
- Ernie has been in touch personally with someone at Buckley. Planning to discuss expediting the magnet timescale.
- Issue: order still stuck in the MIT procurement system. Hopefully moving on today. After that we can get in touch.
Possible bottleneck: PMQs?
Beam pipes and flanges
- Metric
Possible approach:
- Order beam pipe to MIT, order PMQ’s to MIT
- Get MIT to do welding of pipe pieces
- Send back
Items that have to come together for that:
- Need to add collimator to design
- Need to get drawings into TRIUMf system
- Need to make sure everything is up to date
- Need to determine pieces needed to connect
Target controls
- Current target controller has an interface where you say go or no go and get position as analog voltage over linear readout. Not ideal but it depends how we want to integrate it into the rest of the system. Could replace electronics with something
- Need end stops (switches) on both sides that tells it to stop
What does TRIUMF control system have?
- Switch inputs and analog control inputs spare, then can do this all in EPICS
- If not, we need to maybe build new electronics.
Can this not go farther away from the target? Could we put motor control and whatnot in the hut?
- More worried about readout. But 50 m is OK - we’re doing that now.
- 10th mm resolution on position is probably good enough
Thomas: can we involve controls group?
TODO Stephi: set up meeting between controls group and Jan.
- Jan will bring options and questions.

Simulation todos

Need to update Cameron’s studies of distribution of hits in GEM plane with up to date models, and try what happens when moving in and out of plane like Doug’s studies
- Right now, the plan is to get the transfer matrix from the simulated magnetic field. If the simulated field is correct, we’d get the GEM location correct.
- What this study would tell us is can we see if they are in the right place from the image in the GEMs
- If they aren’t, then
We need to document everything.
Can Jan present us with explanation of how the reconstruction works?
- TODO: Yes, he will do for an upcoming simulation meeting
- Thomas can help
- Can we map the field? That would give us what we need. That seems like the thing to do.

TODO Everyone:

Everything needs to go into the TDR.

MIT update

If you have a 30 MeV beam and magnet is tuned for 30 MeV,
- TODO Doug: send Kate plots. Post plots in TDR with description of what we are looking at.
Doug has plots with no multiple scattering.
- Shows the impact of not being at the focal plane.
Cameron has plots with multiple scattering; showed at previous collaboration meeting
Jan and Michael discussion
- C-slit is a collimator with small holes at known angles. If you have a transfer matrix that is good enough to reconstruct what hole a track came from, you can use it to calibrate your reconstruction basically. We don’t have one.
- Helpful for some things, but is it helpful for finding the focal plane?
- Was there a plan for a rotating collimator in the spectrometers?
  - Collimator is fixed at the moment.

SBU update

Got the STL file export working correctly, and are able to edit the PEEK
- Solved overlap issue.
- TODO Win: make STL files for everything
Jan has a student who would maybe work with him on the target.

Trigger updates

Ben & Gabby: Konstantin moved the MIDAS triggering from old page to new page that is dissociated from alpha-g
Document what is where? Ben: in progress

Hampton updates:

Multiple MPD modules and different firmware versions available
Cosmic ray data from Ryan and Manju
Start next week’s meeting with update from Ryan

February 21, 2024

Chairing today: Jan

MIT status update

Everything has now been ordered. No update on the delivery date.
- Chamber order is out; waiting for confirmation of delivery.
- Magnet order is in process at the moment, doing some admin to get it placed.
Getting gauges that TRIUMF likes; getting info on pump controller
TODO: need a meeting to integrate ladder controls into EPICS, slash modify them. Jan can do it?
- Yes, Jan can do it.
- Doug sent diagram for controller to me, ages ago.
TODO Kate: find this info, send to Jan, post on wiki, figure out with Jan and team who should set up what.
TODO Kate: reopen thread about gas lines to e-hall. How do we monitor?

Mike & the triggers

Mike showed some slides
Plots seem to show potential TDC problem rather than necessarily cabling or board problem
Cause of double peak? Different cable lengths
Any evidence of attenuation? Not really studied yet

Ethan

Discussion in simulation meeting around radiation damage for SiPMs; general agreement that we may need to actually expose detectors to radiation and see what happens to them. Reminder of that. Sent around MUSE results.

Bishoy

Got Radgen working nicely. MainzGen is also part of larger cooker framework and can also run it standalone.

GEMs:

Doing a comparison between some firmware versions?
Would make sense to have a single unified GEM control framework that everyone shares. No need for it to be separate for MUSE and DL.
- Michael: nothing actually new for DL; just cherry picking a sub-set of Muse for this.
- Why not just update to full Muse version? Trying to do less work.
- Means everything is preliminary and to be discarded again.
Currently seeing close to nothing on every 4th channel?
- Baseline? APV data are fine, but signals seem to be missing (?)
- Seems to be a version difference thing also
Mike: critical to have event display working for us here at triumf
Doug: we also need it for calibrating the magnets
- Discussion followed on whether or not this will actually be useful for magnet calibration

TRIUMF

Doug P: did find a fault on the HV connector. Lifted it out of the oil bath and are cleaning it up before replacing the connector.

AOB

Collaboration meeting?
- Await confirmation on delivery dates for vacuum system. Could be shipped in June. Could schedule meeting in end of June before things arrive, or have people come for the meeting once things are already here (would be in July)
- 2.5ish days.
- TODO Kate: Send out doodle poll or excel sheet to see which weeks people are available.
TODO executive meeting: either Friday or after 4 pm SBU time (1 pm our time). Try a Thursday at 1:30 pm: 29th or 7th. Send a doodle.
2 x 4 x 16 sodium iodide crystals that could be used for cosmic rays. Better than what we’re using? Unclear. Bases are grouped in 8s, and each crystal takes around 800 microamps at +1000 V. Mike: we should have power supplies for that. Doug isn’t sure.
- Send us a picture so we can take a look.
- Doug says Ethan and Jared and himself had set these up and were quite pleased with the result. - Michael is also interested since one of his scintillators has a broken light guide and they’re pretty noisy, so they aren’t getting great results with their cosmic stand. Doug: yeah could also send a pair down to Hampton.

February 14, 2024

Chairing today: Kate

Update on beamline and TRIUMF status

Laura and Aveen have been working on hammering out beam optics agreement
Showed slides in sim meeting. Now have agreement they are happy with.
E-linac: gun is broken, but it seems just a matter of getting a spare part.
Collimator good to go by June. Parts ordered.

FLUKA/safety

Ethan’s results. Bring to safety people next. At this point we’re becoming a little bit statistics limited for damage to detector components, so Ethan is moving things onto the MIT cluster.
Compiled it all in the past, so it’s just a question of how FLUKA handles processing

Update from MIT: magnets and chamber

Good news: scattering chamber should be delivered by the end of April.
Vacuum chambers for the spectrometers will go out for order this week and we expect them to be delivered around the middle of May.
So all the vacuum systems can be assembled and tested at Bates in May and June, and in principle could be shipped to TRIUMF in June. Would allow us to assemble vacuum components all the way to the dump.
- Allows assembly, testing with beam, etc. So projection at the moment is that would be available in June.
Delay in production of dipole magnets at Buckley. Quotes look as expected but delivery is 8 months. Puts delivery of magnets in October.
- Would expect delivery of magnets to TRIUMF at the end of the year.
- Ernie will try to speed up the process once the order goes out, but there’s no guarantee it will be faster than this.
Jan: can we do something else?
- Kate: just do it, it will not save time to go elsewhere
Option for shipping stuff here: does not include the vacuum chambers in the magnets. So either:
- Delay installation of everything and break vacuum once
- Or install everything else, test what we have, then break vacuum again to install magnets.
Stephi to check with Dimo and Thomas
- Possibility to put in collimator at the same time as the chamber etc.
So looking at possibility for two breaks of vacuum: one in late June and one at the end of the year.
Jan: can we do just one? Doesn’t help.
Richard: later schedule for the spectrometers would probably help the GEMs, right?
- Michael: we’ll have a much better tested system on that timeline. More time makes this a better product.
From MIT’s side, if we decide to do the two-phase commissioning, they can support us
- Stephi points out that we can solve problems in two steps too.

Update from Hampton: GEMs

Work in progress. Using a source, working on latency and high voltage scans.
Main task was to interpret the data
Multiplicity challenges, there are thresholds in the analysis that can be varied. They are working on those: systematically scanning the thresholds to get efficiency outputs
Operating at 4000 V, highest they have gone at this point.
Will work on maps soon.
Need to resurrect reading out multiple GEMs
New schedule works well for them
Ryan will have some plots.

Update from TRIUMF: triggers

Working on the analysis
Somewhat unsure of Konstantin’s report at present, but we did fix the i2c problem.
Issue with new mounting brackets. Nicolas meeting with Gabby and Ben to work on light leaks.

Simulation updates

Status of STL conversion from solidworks files
Win is making good progress on being able to merge big pieces together, but we haven’t figured out how to merge
Try importing stuff without screws
Keep trying ourselves.
Set up a meeting with Joe in a week or so if we haven’t got it sorted out ourselves.

February 7, 2024

Chairing today: Jan

Executive meeting report

TRIUMF really wants to support DarkLight
Need to follow up ourselves and keep the doors open
Richard has talked with Jeff Kraft and exchanged emails with Oliver K. Our cavities are Tesla type cavities
Hold another meeting soon where we will talk about MOUs, collaboration agreements, etc

Laura sim update

Beam optics: still working on it. Had a pretty productive session last week. At this point we are mostly hammering out a definition for what agreement is.
MIT doesn’t have STL files yet? Can Joe make those?
- Story is trying to use student version of Solidworks to do this.
Ethan gave a really interesting update on the shielding for FLUKA. Slides can be found on the Github.

Accelerator update

Something broken in the HV cage. Known since the new year that there is oil coming out of a tank with an HV resistor. Not too sure why
Accessed the e-hall on Monday. When they touched the oil tank, it was very warm. So that’s worrying
Resolving a bunch of different mysteries but need to fix all of this. Might be able to limp along for another couple weeks, or might have to shut down early. It’s a simple fix but it needs to happen.
Can’t move the shutdown.
If we can limp along for another week, might be able to do background tests for Mike
Thomas has characterised the performance of the low energy collimator but hasn’t had a chance to plot it yet. We’d love to see it though.
- Can’t put full CW beam on that collimator because it has a power rating around 50 W
- Thank you Thomas!!

News from MIT from spectrometers

Out for competitive bids on chambers
Magnets converging. Based on Ernie’s interactions with them, they can’t make exactly what he wants so they are working on finalising a solution.

Trigger updates

Solved i2c problem: shortened cable & changed resistor.
Taking data over the weekend and last night. Ben showed some plots
- Plot of time difference vs width: weird two peak structure
  - Jan question: is banding in time direction a TDC binning issue? Ben: not sure yet, haven’t had time to look at it.
  - Michael: could it be n photons? We don’t think so
- Jan: has TDC actually been characterised with a signal generator? Mike: supposedly it’s all calibrated, but we need to check.
- Plot of time vs width with and without clamp on end of scintillator - no width structures
  - Ritu: this has worse resolution than the previous one, why?
  - Mike: different coupling mechanisms
  - Ritu: do we have same condition for scintillator 1? Yeah that’s this one, and it’s just not as good
- Top of plot flattens out correctly, giving us square shape, when we include the clamp
- Ben: if wrapping isn’t tight to the scintillator, we get weird reflective paths that could extend path length, maybe
- Jan: but that doesn’t line up with path length. Could clamp improve connection from sipm to scintillator
Question to Jim and Ernie: can they send Jan instruments on vacuum chamber so he can plan?
- Jim: preferred vacuum gauge?
- Doug: we split into convectrons and ion gauges
Ernie: has received power info he requested?
- Not yet
- TODO Kate: need to poke Mel that this isn’t a work request thing

GEMs:

Working on measuring efficiency vs operating voltage with St-90 source and scintillator triggers
Need to go to higher voltage, still working on that
These are higher than from Japan - yes, bc gas mixture has changed. They are now running 75/25 like us. This should correspond to ~200 or 250 V difference in operating voltage
Mike: should we worry about gas mixture given humidity problems in Vancouver?

January 31, 2024

Chairing today: Kate

Other items

Daniel, new potential undergrad from Stony Brook

MIT chambers and magnets

Doug spoke with Jim and Ernie yesterday. Finalising discussions with Florida company doing spectrometer chambers. The company had suggestions about making it easier, and Joe is updating the drawings to match.
Ernie is talking with Buckley in NZ. Going OK. They are making drawings of the coils that just needs approval and we’ll go ahead with that.
Ernie still waiting for info on input voltage in phase from Arthur.
- TODO Kate: ping Arthur to put us in touch with electrical guys
On STL files: Joe will get to it today, and then “something”. Told him we were exploring possibility of editing and translating using Autodesk. But he will push most recent versions to Dropbox, and will try to get us the STL files too.
- Come back to discussion with TRIUMF vault manager in 2 weeks or so.

GEMs

Working on analysis of data.
Last time: latency scan and high voltage scan. Working on efficiency definition.
On hardware side, still need to swap out the potentially failing APV card and see if that fixes it.
At TRIUMF, moved GEMs back to ArCO2. Hope to poke them again in the next few days.
TODO MIT: send instruments on spectrometers (gauges, hall probes, etc) to Jan so he can start looking into how to read them out.

Triggers

Konstantin and Ben set the voltages on the distribution board and took a run on the weekend.
Errors on the i2c bus over the weekend, Konstantin is unsure what happened. Still needs to be diagnosed.
Two of the counters were rather noisy so their time resolution was worse. As usual, 300 ps without time walk on the best one. Other one will still need help.
Have to decide how to handle bonding of silicone connecting light guide to SiPMs. One will give better connection but be harder to repair, while the other will be fast to repair but needs pressure.
Bought heat sinks for the backs of the boards.

E-linac update

E-linac ran for almost 80 hours last week. Longest down time was 4.5 hours.
Got machine out of the ditch and now we can turn attention to the users.
Mike question: can we raise the current? Stephi: still some glitches we have to figure out, that relates to waiting on the power
Once we have the collimator, we won’t have to worry so much about these things and it will be easier to turn up the power.
Richard reminds us that we actually have a lot of work we can do, and science we can do, at low power. We could probably already do something very useful with what they are doing now.
Thomas: yes there’s quite a bit of flexibility in what we can do.
Richard: great, cause we will actually want to start small.
Jan: to confirm, you could now run on CW? Thomas: no, 90%. But that’s enough for now. With gun improvements we can try to run with lower peak current, but haven’t done it yet.
- In the past, limited to peak currents above around 100. But we saw 300 last year, and based things on that.
- Issues we were seeing at that point was from RF, rather than gun.
- Other case, what Richard wants, will let us get lower. Should be able to go below 100 microAmp peak. Duty factor is anywhere up to 90%.
Thomas: should try lower peak current, putting collimator in, etc
Shutdown: when, how long? Construction starting around March 1 and will take at least 6 to 8 weeks.
Mike: can get radiation monitors for radiation monitoring.
- Can we get half an hour at 1 to 10 kW with the monitors in?
Will open the hall next week, so we can go down at that point to do that.
Thomas: also want to stick the PMQ downstairs.
Open hall day: they can probably do Tuesday. Then it will be a week before we can get in.
Confirmed plan re safety report to Ethan
- Need to buy new PMQs.

Simulation/beam optics update

Scattering is now the same
Thomas: one thing important for FLUKA is knowing about the tails. The tails are what is creating the losses. So that’s a reminder that we need high stats. Ethan has done high stats runs in the past, and can do them again when we do this. It’s like 1 part in 10k that’s the problem.
Need to get model from Aveen

January 24, 2024

General news

Coordination meeting tomorrow, 2:15
TODO Jan: make Indico agenda for tomorrow; make list of points to discuss if we get time
MOU - Doug will give to Richard. We need to go back to the lab and ask them to modify the things that need modification.
Immigration rules: 120 day rule

Accelerator news:

Attempt #2 at the 3-day running
1 kW, around 28 MeV (= 30 microA?)

Magnets etc news:

Jim: making drawings for chamber; in contact with the machine shop. Scattering chamber is on schedule. Hope to get this chamber into their system in the next week or so.
Ernie: figuring out the power supplies.
- Hasn’t talked to New Zealand yet but planning to talk with them Friday or Monday. Order will go out shortly after.
Next plan is to start going through the rest of it, just focusing on the chamber to get it out.

Trigger update:

Ben news: been waiting on Nicolas to finish new setup that changes silicone curing. Gabby and Ben connected all the electronics back up and it seems to work. Now fixing a light leak. Hope to take data by end of week.
Powerboard order for pre-amps has gone through. Probably 2-3 weeks delivery time

Simulation:

Works in progress. GEM digitisation ongoing; FLUKA shielding ongoing.
Beam simulation side: need to discuss with Thomas and Aveen, but we are making progress on understanding what the differences are and why this is happening

GEMs:

Ryan: latching actually causing troubles, but now fixed. Redid a latency scan and started to see GEM signals. Working on code to see clusters.
Also did a cosmic run and it looks like there are some strips in the APV that aren’t working. Swap in some APVs they know work to identify whether it’s an APV issue or an issue with the back plane.
Michael: showed some plots of efficiency vs latency, etc. Dead strips visible as white streaks in a hitmap, very useful
Need to work towards a more sophisticated efficiency definition
Mike: operating voltage tested before? Michael: in a 70/30 gas, using 4100 to 4200 V. Then there’s a gas mixture dependence of the voltage. At 75/25, it should be around 5% lower, around 3800. Here maybe expect to operate at 4000, but approach carefully from below.
Plan to move TRIUMF GEMs back to real gas next week. Mike: still ominous rumours of a bus strike.

January 17, 2024

Updates on simulation

Regular meeting on Monday
Made some progress on GEM digitisation
Ethan made progress on the detector shielding sim in FLUKA
Doodling for new meeting time, fill in if you want to attend
Laura and I working on ironing out differences in sim

Updates from TRIUMF

Managed to fix problems with pump (yay!)
Continuous beam delivery to Faraday cup for several days before Christmas
Started yesterday morning for 1 kW continuous beam delivery 20 MeV to demonstrate 3 days continuous beam. A few issues have come up.

MIT

Quotes out on scattering chamber now in addition to spectrometers
New design is easier to manufacture and should be totally fine
Still need to get STEP files

Hampton/GEMs

Got latch triggering working with gate delay generator. Fixed time. Got it working with a source though
Now measuring latency
Next step is smart controlled latch release
Then test the software for cluster reconstruction and start mapping

Triggers

Nicholas reports he’s redoing the silicone for the current systems. Hope to have one complete system ready to test tomorrow or Friday.
Lots of Nicholas’s time in this at the moment. Hope to have two systems back collecting data late next week or early the following week

Richard’s update

Had a good discussion at the collaboration meeting on subject of increasing the beam energy
Ask to Kate and Jan to hear from the lab about the options. A presentation or writeup about the possibilities and how we might realise them.
- Option A, option B, possible timeline, what the costs are.
- Accelerator div needs to tell us what they want to do and what they would need to do them, and then that’s a problem we can try to solve.
- If we build a unique facility for electron scattering in North America there will be options, but the design has to be driven by the lab.
So if lab drives the design, we can see how we can help.
Need commitment from the lab that we can keep using this area for an electron scattering facility
So they need to tell us what they want, rather than us telling them.

January 10, 2024

Magnets & chambers: status?

Haven’t heard from Ernie since the new year. Has been talking with Buckley. Requested a new quote and some details.
Met with Jim and Joe yesterday and scattering chamber is in good shape. 15 weeks delivery from last week (end of April).
Vacuum chambers for the spectrometers: Jim and Joe have been making some modifications so it’ll be possible to manufacture, then will send it off to the same people. Found a way to make the same thing with half the price.
- They’ll show what they’ve done to Doug at 1
- Doug will make any physics changes that are needed
- Michael is asking about rates into APVs
- TODO Cameron/us: add sensitive detectors in the simulation and see what the rate is in the scattering studies that ends up in the APV
Chris will officially be done with DarkLight at the end of the month. Before then, need to verify that Joe can transfer files in whatever.
Kate TODO: set up access to vault for Joe.
Convergence on the PEEK? Not yet
Awaiting answer from Ernie on increased power supply cost if they go up high

GEMS: news

Michael showed some nice slides
Reminder that they were seeing readout errors with cosmic for the triggering
Now have a simplistic latching mechanism with gate generator. Needs 1 ms to 2 ms busy time.
Really simplistic, fine for testing but not what we want for the experiment
- More sophisticated one uses V262 module and releases it with last line of frontend program. Need this, or something else that produces a logic pulse in response to a line of the software. TODO: ask Konstantin for that.
MPD receives data from APV on previous trigger, then needs dead time, and does not produce a busy signal. So what you’re essentially doing is manually adding that.
What is actual readout time for the GEMs?
- Michael says 200 microseconds is “aspirational”
- Around 200 for 4 APVs, and we have 13. Assume it’s somewhere near 700 or 800 microseconds.
- Can pull out timestamps and evaluate differences.
Takes up to 2 ms to clear out all the FIFOs.
Guess on upgraded system: will we see it by December of this year? Michael: maybe. Lead time on VSX+VTP is around six months. With that scheme we will fix a lot of these problems.
- 5 kHz is the hard limit for APVs.
- MPD processes the APV data that arrives: analog to digitised. Firmware then forms an event, binary blob, that has the sequence of all digitised words. So that’s then translated to the crate. So it’s the event creation on the MPD that is the limiting factor.
Thinking about adding heat sinks to the distribution boards - they get super hot - or a fan
- Heat sinks are like fingernail size.
- Peter has some heat sinks, could get them from him
- Excess heat also depends on over voltage. At 5 it should get pretty hot. APVs are drawing a lot of current, and it can drop if we have the wrong wire gauge.
Laura filled in on status of GEMs at TRIUMF
Software sharing: Git!
Logs: google docs. Laura will share hers.
- One doc for TRIUMF, one for Hampton, and we’ll each have a link to the other’s
Jan and Ethan need to think about event synchronisation across GEMs. Once we move to more crates we need to be careful about that.
Could generate a trigger ID and distribute to all subsystems
Ethan: should think carefully about a nice simple architecture to do this.
Issue with delay between trigger and latch turning on? Mike knows how to do this better. Gave some advice on using output from the same discriminator

December 13, 2023

Integration & safety

Radiation safety
- Long discussion with Thomas yesterday on set of conflicting/contradictory instructions we’ve been given
  - Largely stemming from the major changes at CNSC: consequence is no one at TRIUMF knows what the right answer is
- We think current goal is to treat DarkLight as part of E-linac commissioning plan
  - Commissioning plan
  - Safety assessment and review of the experiment
- We should keep everyone higher up in the loop about this plan, remind them of it regularly, and let them object if they learn more that contradicts this
- I will meet with TRIUMF scientist working on licensing conditions handbook this afternoon; he may tell us more.
- No disagreements in the room
Beam parameters request: coming up, will circulate an edit link
- Screen share Stephi’s doc
- https://www.overleaf.com/7991641436kygntxgvtnyj#740f59
Next up: have to move forward with TRIUMF’s next reviews. Gate 2/3: could we get this done by early February?
- Outstanding items: finalised drawings, beam optics, radiation safety information. Drawings for surrounding stuff (hut, cable trays, etc) - should be easy
- This review will look in detail at the design and results of our earlier reviews and ensure everything is OK.
- Thomas and Stephi need to test fast valve. Ask Dimo to test it
At commissioning and running, if other groups need consumables, should we get them a sub account? Or how do they want to handle it?
- At Olympus, set up an account at DESY.
- Maybe easiest to let us do things and let them reimburse us

Optics:

Lots of debugging work. Suspect last remaining item is RMS definition (off by some geometric factor). Discussed with Thomas
Initial running will be limited to 20-30 MeV without new optics.

Design/drawings for chambers and magnets

Status of order? Bid package sent out?
- Richard met with Ernie, Joe, Jim yesterday. Ernie has requested a new quote from Buckley. They have fine tuned magnet and coil so he wants a new quote. Sounds like we’ll get it by Christmas.
- Scattering chamber is out for bid. No news from Jim on time frame.
- Vacuum chamber is good to go, caveat the exit window pressure test. Will meet with Joe and Jim tomorrow to go through a few details
  - Geometry has tracks centered in the GEMs, from what Cameron shows. But GEMs are shifted down towards magnet yoke so we expect trajectories in the lower part of the GEMs.
  - Need to check with new geometry.
  - Doug will design this and Cameron can modify his geometry.
  - Trigger scintillators need to be adjusted so they overlap with the particle trajectories. We don’t have design for the supports, but that’s something to go over tomorrow.
Jim also raised that there has been no design for the shielding.
- Spoken with Ethan: neutrons are pretty low.
- Idea is wall of poly vertically, lead box around detectors.
- Add a bit of lead with the poly? TBC. Let’s check without first.
- Size of GEMs, horizontally: worrying. Take this into account.
Joe: thanks for Dropbox link! How final are these? May I pass them along to people at TRIUMF?
- Likely will be asked for installation drawings (whatever those are called) as part of Gate 2/3.
  - Suspect we will also be asked for results of failure tests for vacuum. Are those something that have to wait til we have the vacuum chambers actually in hand?
  - Easiest to just use the actual vacuum chamber
Best way to share with everyone? https://www.dropbox.com/scl/fo/iuufqqevskmgk00kz6sc2/h?rlkey=f3d4e6yqhurjypkgpvc2jb3s2&dl=0 Can people test this?
Need to define interface between MIT’s responsibility and TRIUMF’s responsibility

GEMs:

Manju started getting Ar/CO2 and source set up. Will be able to get more progress this week. Working on latching to get started with cosmic rays too
Laura: got a source; moved the GEMs back to Ar/CO2
- Where gas bottles live at TRIUMF: Mike can show us

Triggers:

Low voltage distribution board is working
Other tests later this week.

Argument about where stuff goes

Big argument about where stuff goes
Compromise is good, but so is rationality
Let’s get a cost estimate and see

December 6, 2023

Chamber plans:

Design work now being done by Joe Dodge (?)
At BNL this week
Chris will forward his email address and I can send a ping to him. He’ll be able to share this.

Support for GEMs: ideas on how to mount them, but nothing concrete. Joe will do the design.

Mike suggests the scintillators should mount to the GEMs as a single detector package, and mount the whole thing to the magnet.
Chris agrees. So this should be the plan.
Joe already has the black plastic supports and GEMs. And we can discuss.

Gas tank location

Manifold and flow meters downstairs.
Bottle upstairs; single tube down.

Storage

Request from Ernie: we wanted magnet power supply up on the roof, which means a 50m cable down to the magnet.
At the magnet, 20 V and 120A or something. But if we drop 4 V going 50 m, then you need a 24 V power supply up to a 30 V supply.
Me: can we just spend a bit more and figure this out?
This will come up again and again. Request will be that we put things on the roof.

Controls

We will have ion pump and NEG pump under the chamber. Do we control that, or does the e-linac?
Valve should be interlocked with gauges. So unless gauges on both sides
Will be integrated in EPICS.
- Doug: but when we’re starting up, we’ll want to see if it pumps down without opening the gate valve to the linac.
- Ultimately very happy to have it part of the TRIUMF system. But roughing pump initially will just be on a button, etc.
Get the dialogue going with the right people to see how we should coordinate this.
Question: do we have a portable pumping cart? TODO follow up and check that we can roll in a roughing pump.
TODO set up a discussion with vacuum people at TRIUMF to figure out all these issues.
- What if we have to change targets? Under what circumstances do we open vacuum and change something, if we have to, and how do we do it? Establish a plan/procedure.

Access

At the beginning, there will need to be a lot of in and out during commissioning.
Later is when we could avoid it.

Optics

Worst case scenario is 10 MeV at 300 μA. But let’s go the other way - find max current per energy and Ethan can use that.
Kate to check with Thomas on this way of defining what’s OK

Report on GEM progress

Ryan: working on setting on trigger. Borrowed a generator from JLab, working on getting it going.
Trying to get some output visible on the scope. But Ryan is heading off to PSI now.
Laura: physical setup is ready to go, now getting files off the computer.
- Got the code for the MOB safe - it’s in the electronics room hidden under a table.
Is Ryan trying to use a scintillator for triggering? Yes - trying to set up a trigger latch and a busy latch with this gate generator. Not sure if the register is working.
Have to have (good to have?) the busy signal since the rate from the source could be pretty high.

Triggers

Mike, KO, and Nicholas met yesterday. Nicholas has printed some new pieces for the 8-scintillator array. When Ben is back, wants to take data along the length of the scintillator to get end-to-end timing resolution. Continuing testing, going well.
Peter’s testing continuing on the distribution board, looks good

Meetings

Keep using Doug’s zoom room, and he will make and propagate more meetings into the future
Time fine through end of January. MIT people & Jan won’t know time slots for teaching til later.

November 29, 2023

Magnets & chambers

Sent drawing package for dipole chambers to Jim over the weekend. They chatted on Monday with the Bates designer who will be going over them
TODO GEM supports: can ask Jim about it, he might be able to do it.
Richard met with Jim and Ernie on placing orders, things are going well
Ernie has whole package for magnets, imminently about to send to the company in New Zealand

GEMs:

Hampton has been helping Laura set up the external trigger via the pulser
Laura has a discriminator ready to go and that will hopefully help

Triggers:

Work in progress, lots on ongoing measurements

Simulation:

Ongoing: getting resolution code running with multiple users
TODO: redo resolution

E-linac:

Still trying to figure out what’s going on with the pump. Relying on the vendor.

[Gap without minutes taking system.]

November 22, 2023

GEMs:

Controller is working
Want to talk about APV support design.
If we’re gonna 3D print them, can probably do Solidworks native files.
Length is 500 mm at longest edge
- Doug can do 256 mm so if we can do two halves and glue them together, we’d be good.
Or easy to G10. Could do it in the scintillator shop.

Trigger

2 new boards installed on the top counter. One is on the bottom counter. Konstantin reading out all 8 counters.
Solved the problem with wiggles in the spectrum. Slightly better than 400 ps right now and took some data yesterday.
Next is test the distribution card and look at the temperature sensors on the boards, and check that we can do the fine control of the bias voltage.
Order has been placed but have to give them the go ahead in case there’s any other changes.

Chambers

Jim in process of transferring files and getting data vault up to date. Meeting Monday to confirm.
For magnets, Ernie writing up a bid package to send out by Friday. Designs complete at this point.
No news yet on delivery date from manufacturers
Will send a copy to us when it’s done. Will also send FEA report when available.

Simulation

Let’s check in on Monday.

Other

Richard has been looking at electron scattering from carbon
Various papers on elastic, Moller, and multiple scattering from carbon from Illinois in 1951.
Richard will look into this and let us know

Kate to track down BBN results

E-linac

No news from e-linac
Still a bit of a water pressure struggle but people are looking at it
Started cooldown and moving towards a running system

Me and Jan can take turns chairing.

January 10, 2023

General Meeting: https://indico.mit.edu/event/672/

Chris updates about the additional hardware on the target chamber (see sample image ) uploaded to indico). Doug Preddy asks how hard it is to access the neg pump for service. Chris clarifies that there's no moving parts or likely reason to access it for service, save to bake it out. Can be removed without affecting the alignment. Thermal cycling won't affect alignment either.
1. Ross asks what the desired alignment precision is. Not clear what our requirements are.
2. Doug Preddy points out they ran the survey to align the external arm to the internal arm, and ran the stepper motor in air to see how stepper positions corresponded to target positions. Kate notes that the ladded in Chris's drawing has four positions, while our as-built version now has only three, in order to keep the ladder out of the way of the inlet flange when at maximum extraction. Doug wants at least out of the acceptance of the inlet port. Anything beyond that is a problem in the beampipe, not the chamber.
Kate sent a document around with a series of follow-up points (dated Jan 9, 2023) from the collaboration meeting. Doug H. is mostly worried about how to handle the import/export constraints, and how this interacts with in-kind contributions that will trigger matching contributions.
Talked about valves for worker safety. Jim says we expect to have shields as necessary, then remove when we are ready.
Jan brings up Long Range Plan. The larger our operating funds we can get from the US, the smaller we need from other sources. $7e6 is the total operating funding (see transcript for more details...)
Discussed May collab meeting at TRIUMF. Have to schedule to avoid a student seminar (eg by going to the hall during that time slot)
Kate reminds that the simulation meeting will happen on Thursday. There are two different angular distributions, both heavily documented, and now we need to decide which version to believe in.
More design discussion. Among other things, target ladder control box will be designed to interface with TRIUMF EPICS system.

January 03, 2023

General Meeting: https://indico.mit.edu/event/671/

Chris (in absentia) noted addition of a positioning system (of all detectors), instrumentation (gauges, gas analyzer, etc). Modified target ladder, chamber modified to allow bellow and BPM upstream, as requested by TRIUMF.
1. Doug still wants to see the changes to the target ladder -- intended to have the ability to rotate in addition to going up and down? Doug will talk with Bob Abruzzio so that the target can be controlled by EPICS.
Ernie and Jim have solved the problem of the pole tip design. Ernie has found a company who will machine the tips and wrap the coils. We do not have the finished design from Ernie about the coils yet. Once we have a hole to bring out the leads in the design, we can pass that to Xiaqing and onward.
Story reports no update on the angles: Simulations team has encountered 'oddities' with the generator, counter-intuitive results with the rate as a function of angle. Wanted e+ at ~20 degrees, and e- at close to 40 degrees. Dean, Story, and Julia all seem to have those angles work, but there was an issue with which particle was which in the code. Ross forwarded his annotated copy of the mainz generator. The next meeting is likely to be thursday, Jan 12. Ross will be sure to attend! Doug suggests Ross could reach out to Jesse and try to reproduce the angles from the current MainzGen. Notably, we can proceed, though we need the angles fixed before we finish building the chamber.
Richard reports on the LRP status, and asks about 'significant capital equipment items' which might be of use for the program, which the US could conceivably provide in the next ~few years. Mike H. points out that they are less interested in the recirculator at the moment, but that the timeline that best fits the TRIUMF schedule would need to be 1-2 years or so, not so long range. He proposed the RF deflector that would allow to split the beam, but notably there needs to be a US involvement in the science.
Mike points out a ~2-3 year postdoc (or research associate) position at TRIUMF, and encourages applicants.
Next Collaboration Meeting? May24-26, May31-June2? (notes May 22 and May 29 are Victoria Day (CA) and Memorial Day (US), respectively)

12/Sept/22

General Meeting: https://indico.mit.edu/event/518/

Welcome Julia from UBC and Story from MIT!
Should we change the date and time of this meeting?
1. Doodle poll has been circulated - 11 responses so far
Chris Vidal is now working part time with DarkLight
1. Working on designing the dipoles and positioning them
2. Positioning dependent on beam optics calculations from TRIUMF group
TRANSPORT code is available if someone can find time to use it
1. Open source code on GitLab
2. Should be simple enough to access and run, just need to find time to run it
3. Calculation should be ready before document is due
4. Aveen can give a report on status
What angles should the spectrometers be placed for the 30 MeV beam?
1. Convenient to look for 13 MeV/c^s mass at similar angles to 17 MeV/c^2 at 50 MeV beam
2. Maybe we look for 14 MeV/c^2?
3. We need to optimize, but not a huge difference between the smaller masses when it comes to reach
4. 20 degrees or less becomes very difficult to measure, magnets may be in the way, and beamline weld
  1. Maybe dipole field kick in the beam at that angle
  2. Need to redesign the target-beam line interface for optimal running
5. Shifting to 30 degrees makes things much easier technically
6. Can we place the spectrometers farther from the target? Might make it easier to measure small angles
  1. Likely won’t help too much, as biggest issue is where scattered particles leave target chamber near the beam line
  2. Redesign of target chamber would be necessary to fix interface
7. Need to have more input from beam optics and simulation to determine optimal configuration
Brief simulation update
1. Previously ran some code with a 30 MeV beam and some at 31 MeV, in the process of unifying plots and results
2. Will take a look at 14 MeV/c^2 mass as well
GEM update
1. Michael has sent some preliminary estimates of GEM thickness, numbers need to be updated
Need to schedule conceptual design review at TRIUMF
1. Trying to balance being too soon without final optics, but don’t want to push back to November
2. Initial review is only for 30 MeV beam energy
3. Do we have a drawing of existing available area?
4. And when will we have a full CAD drawing of the entire experiment
5. Can show preliminary schedule for experiment at review
6. Should likely also show commitments from universities and individuals and present to committee
  1. DarkLight should also internally discuss this

29/08/22

General Meeting: https://indico.mit.edu/event/516/

Video recordings: people who want to view recordings need guest accounts. Send info to Doug.

Magnets:

Doug illustrates why the gap is as large as it is - to allow us to meet angular acceptances
Challenges of 20 degrees:
- Doug showed image with 20 and 25 degree spectrometers, 2 PMQ’s, 2 quadrupoles.
- 20 degrees with -2 in acceptance is right where the beam pipe connects to the chamber wall
- Quad best location is right up against target wall
Need to converge on 3 simulations in parallel:
- Beam optics solutions
- MC for angle combinations of physics
- Mechanical design that doesn’t have things bumping into each other.
Can Chris at MIT do the details of the geometry/mechanical design?
Add window at the bottom of the quad?

Quadrupole:

Do we want to update quote to 2?
- Need to ask how close we can put them to each other safely. How close can we put them to a dipole?
Do we want to ask them to make it split in half able?
- Ernie says: no, too hard to control. Slide them onto a bare beam pipe.
Established quote is for 16 piece, not 8.
Dimensions: 93 mm long and 70 mm diameter on a 50 mm pipe. Mike: can it be smaller? Ernie: probably only by a little bit, and not clear it is the limiting factor anymore.
Need to have a way to fix orientation and z. Ernie: quote says to just tell them what we want. Get Chris to handle this too.
Next step in communications
- Wait til we get a result from Aveen about where we are putting them - e.g. do we need a third one. Beam solution first.
- Ask them to anodyse (?) it, make it look pretty, black or gold
- Ernie: would be easier to do three - no power supplies, no controls, fixed optics. Only knob is moving them up or downstream. Aveen: fine-tune with the third quad.
- Mike still wants to request it be shrunk as much as possible - get Jim or Chris to make some comment on it from our end
Still have question about whether we will demagnetize these. Ernie thinks not. Surround with steel or mu-metal to make it better?
Nice and cheap :)
When is delivery? End of 2022. And probably both come together.

Simulation

Following up on MainzGen and Dean’s plots: acceptance is defined by angle and momentum spread, which are the same as for the old magnet (though the size is bigger). So it will look the same in terms of this simulation. Larger magnet is to permit the acceptance to hit those specs, as Doug showed.
Jan may or may not make the Thursday meeting
TODO follow up with Harald about acceptances of final design. Looks like +/-2 deg in-plane, +/- 5 out of plane, momentum = ?
Can we run at high enough current to pick up elastic scattering for calibration point? Jan: yes with 30, not with 50

AOB

Phase 0 and/or test experiment:
- Schedule from TDR is the current plan according to Richard. Two phase.
- MIT has the money to begin going ahead with the spectrometer construction
- Ernie wants to go with New Zealand company for the spectrometer, but can switch around depending on what we need.
- Aveen thinks: using march shutdown to put in the test experiment is OK. We don’t have a firm answer on collimator or no-collimator
- TODO: send CAD drawing from TRIUMF to Chris. Want a setup such that when we break the vacuum it’s local.
- Oliver: migration of particulates from every warm section into the accelerator. Want a clean tent around for the installation in future. Does not see any problems with the schedule, we just need to know well in advance to prepare. No feedback yet re shutdown schedule. Should present all of this during the technical design review. April and November.
- Doug: we should have another collaboration meeting early in the fall to agree on progress and steps.
Aveen and Thomas in favour of a half-micron Ta target. Jan: shouldn’t be a problem. Mounting could be a challenge though! Aveen: plan around 1 micron and then it’ll just be easier if we get 0.5.
Mentioned a fabrication account out of which to e.g. hire Chris. Is there an automatically stored clear paper trail? We will use all of this.

22/08/22

General Meeting: https://indico.mit.edu/event/515/

Workshop
- Paying $2000 for 25 papers now.
- Editors will help referee
- Nov 1 is deadline for us, so Oct 15 deadline for submissions
Target tests
- Dosimeter doses not yet available yet
Magnets
- Ernie on vacation still but hopefully back by Thursday
- Sabr recommends 16 piece over 8 for permanent magnet.
- Unclear if quote will be for 8 or 16 but they say it’s the same price. KP responding to obtain quote
Simulation
- KP showed Dean’s sensitivity plots (z axis is s/sqrt(b) equivalent)
- Mike: should we try farther in angles? TODO: try smaller angles
- Richard: are we sure these plots have the same properties as the new spectrometer design? KP: didn’t change anything. Doug: but doesn’t the new magnet also have the same momentum and angular acceptance ranges? Yes. TODO: need to verify and follow up whether the physical size matters in this code or if only the angular and momentum acceptances matter. Do we need to adjust anything?
- KP showed slight discrepancy in limits. Will follow up with Jan
TDR
- Should get collaboration to review soon
- Make list of TODOs? Doug will do.
Accelerator
- When can we redo tests near the beam dump? No schedule yet
- Field emission reduction? Big deal, not in the near future
- Richard: shielding the experiment should be key part of plan. Figure out what that looks like.

15/08/22

General Meeting: https://indico.mit.edu/event/514/

Beam tests.
- Bottom line: very high radiation. Getting 300 kHz where the scintillators were behind the lead blocks + cement 2 m from target.
- Supposition is it’s all field emission from the cavities that gets accelerated down the beam line. Still high with cavities on and beam off. Also still high with scintillators looking only at target area.
- Proportionality of random coincidence to true trajectories not studied
- Discussion of how much rate should be seen at angle behind the target - not entirely sure. 90% of beam loss before dump, but that happens all along beam line, not just at target.
- Link to Overleaf with test results: https://www.overleaf.com/read/nqzzdsbrtyqb View only (since this is publicly posted) - ask Kate for edit permissions if you want them.
- TODO: Move scintillators to the beam dump and do measurements again. Field emission electrons won’t go around the corner. Requires lengthening cables, repositioning scintillators, finding more lead and increasing shielding if possible. Mike notes difficulty in finding spare lead at TRIUMF.
- TODO if possible: rough energy measurement.
  - Could possibly do with different thicknesses of lead in front of scintillators.
  - Bringing more sophisticated detector (e.g. sodium iodide) to TRIUMF possible but probably too difficult on reasonable timescale
- Richard: raising context from JLab. Recorded here: https://www.sciencedirect.com/science/article/pii/S016890021300867X
  - Also saw tons of field emission, using higher energy and higher intensity beam.
  - Suggests shielded setup like they had before. Ideally want shielded from every direction except interaction point.
- TODO: Kate and Mike come up with explicit task list and coordinate with Thomas for day to do it. As long as task is order half a day, could happen any week
Proceedings
- Deadline is based on Moore Foundation money requirements - all receipts due end of August. IOP will provide invoice by then. No refund if we over-pay compared to papers delivered.
- General expressions of displeasure at the rush
- Ross expresses strong preference for paying in advance for maximum expected paper number. Agreed to do it this way.
Response to permanent magnet people
- Ernie and Harald should be back from holiday by next week
- 8 pole solution seems adequate to Doug and people online. Email thread to converge?
- Support frame would be our job. Note also that magnets would be thin and require careful handling.
- TODO: coordinate response by email, then pass it along requesting quote. We can also update them on dose rate given results from tests.
TDR
- TODO: Kate needs to write section with simulation and rates.
- Submission timeline: give to TRIUMF at end of September, so anticipate circulating first full draft to collaboration in mid September.
- KP will request more personnel support at quarterly review this week.
- Michael: grad student has done leak checking on existing GEMs. All tested and good.

8/08/22

General Meeting: https://indico.mit.edu/event/513/

TRIUMF beam tests: Examination of the beam spot - Stan

Presentation of images of beam on scintillator screen for different duty cycles and beam on vs off
Discussion about accuracy of this diagnostic vs standard e-linac ones
Can we lower beam current more? Not lower than 100uA according to Thomas
Mount the same type of screen as other e-linac viewscreens on future target ladder for full experiment so they don’t saturate
Might also be able to image the beam with transition radiation since target is conducting

TRIUMF beam tests: Scintillator results - Doug

Presentation of test setup and scintillator results
Coincidence rate increases as function of SRF cavity gradient
Variations of beam on/off, different target sizes, duty factors, layers of shielding etc.
Future test of scintillators closer to beam dump where actual experiment will take place to possibly reduce x-rays
Can’t move the target until next year as that would break e-Linac vacuum which is done as little as possible.
Could use viewscreens or other existing elements as pseudo targets for any tests near beam dump we do before then
Ultimately looks like will need to significantly shield whatever detectors are put in there
Issue with target ladder - somehow drove itself into the beamline despite controller being disconnected over the weekend - bit of a mystery because its an ACME thread
Put off any other tests that might have been conducted this morning
Need to get Bobby to look at electronics why it could have moved on its own
Need interlock switches for real experiment -> These are reasons for design review in September/October

Conference proceedings - Ethan

Ethan - discussion of authors for conference proceedings

Simulation meeting - Jan

Not many people at meeting
Using Cooker again

TRIUMF beam tests: dosimetry - Thomas

Put pieces of dosimetric film downstream of target chamber to get an idea of dose rate for potential permanent magnet and other electronics
Completely saturated in one day - likely more than 40 Gy
Mostly from x-ray from cavity we assume
Jim Kelsey - if you use the right epoxy can still get an electro magnet that will last for our purposes
Doug - dosimeters sensitive to neutrons were used, can look at those measurements too

Magnets - Doug

Doug - get Ernie to finish the magnet design
Agreed w Haralds poles and fields, but redesigning the return yolks with window so ptcls can come out the back - no final drawings yet
Once we do we can run simulations, see if we get the right resolutions and get moving on actually ordering things for installation next year
Stan - if you add a port out the back can you design it to hold a NMR probe? Concern is these things change over time
Magnet should be perfectly predictable and not change over time - no need for NMR probe
Doug wants to do field mapping b4 installation - at Bates or at TRIUMF without vacuum vessel in place
TRIUMF has a magnet mapping table with hall probe that is functional

TDR - Doug

Doug - reminder that the TDR is on overleaf - please read and make comments and edit
Would like to have finished by mid-august to send around as an initial report at TRIUMF

7/25/22

General Meeting: https://indico.mit.edu/event/509/

Workshop - Ross
- money appears to be all sorted, if there are outstanding expenses let Ross know
- remind people to submit for publication, extend deadline to August 7
- Richard is guiding the work on the white paper for the front of the publication
Simulation - Kate
- short meeting last week with progress on reconstruction documentation
- still unclear on reconstruction, need to work with Jan
- need to do list for future tasks
Quadrupole magnets - Kate and Ernie
- in contact with permanent magnet company 4 mm square but length wasn't clear
- for 16 pole need to magnetize at 45 degrees
- simpler option would be 8 pole
- 16 has smaller higher multipole meetings
- company is reasonable so ask them
- try to meet Tuesday
Spectrometer magnets - Doug and Ernie
- Ernie is happy with design and making modification of frames
- was able to make mesh of the poles
- need to converge on the physical dimensions and interaction to reach smallest angle
- Aveen added that permanent magnets don't require cables or power supplies
ARIEL - Aveen
- Thomas is on holiday, back August 2
- currently running at 30 MeV and trying high power
- trying optics of pairs of skinny magnets with same power supply didn't look so god
Detectors for test - Mike
- hopefully have everything lined up
- discrepancy between oscilloscope 20-30 ns and TDC 80-100 ns
- change design to have 32 rather than 40 channels to better match readout
Doug's visit to TRIUMF
- having trouble with MFA
- requested a service ticket to sort out the problem
Funding - Mike
- request to Ottawa went July 15
- August 15 deadline for provincial funding
- don't expect response before June 2023
- Richard writing report for DOE and maybe that will trigger a response for more funding
- we have approval to spend the carry-over
TDR - Doug
- Richard and I were editing different reports
- will merge changes and add a date to clarify the TDR to use
Minutes - Switching to TRIUMF - Aveen and Kate
Next meeting is August 1 which is a Canadian holiday so we will cancel that meeting

7/18/22

General Meeting: https://indico.mit.edu/event/509/

Richard made some changes to the TDR. So far Richard and Doug are the only ones adding things. Others need to step up.
Doug will go to Vancouver Aug 1-16 but still needs to take the safety training
Simulation - Kate said the meeting was short. Trying to setup angles for studies, etc. Need to understand the background generator better.
1. Richard said the JLab simulations used Fluka. Kate said they are just using GEANT.
2. We will have detectors to measure background with scintillators and neutron detectors
Magnet meeting with Ernie, moving slowly
1. Quadrupole design based on permanent magnets but also electromagnet
2. They are in contact with a company for the permanent magnets
Trigger Detector timing
1. Mike showed slides (posted to Indico) resolution 330 to 500 ps
2. Richard commented we probably only need 1 ns and Mike replied that we will time off the beam which is 1.5 ns so timing should be around 200 ps
Funding
1. Mike reported that UBC submitted to CSI on Friday
2. Need to apply for provincial funding next but it is just 3 pages so simpler
3. Richard said there is no news from DOE
4. Jan's request to NSF returned with recommendation to submit it again
Accelerator
1. Thomas at science week and Aveen was sick
2. currently running at 30 MeV
Richard has added DarkLight@ARIEL into the Snowmass report

7/11/22

General Meeting: https://indico.mit.edu/event/509/

Doug presented the outline for the TDR available of OverLeaf link to outline on Indico page
1. Basically a copy of the old TDR broken into separate files
2. Added a section on Simulation
3. Added an appendix for detail not needed in main body
4. Assign names for responsible people
5. Timeline is mid August so ~1 month
6. Simulation should include event rates, background rates, resolution, and comparison with limits
7. NA64 new result
Workshop
1. Little new information but Richard said there was one meeting on White Paper
Simulation had a meeting last week (minutes on Wiki)
1. Mike said they would use a different platform to generate more data
2. Software is now reasonably well understood
Magnet
1. Jan, Harald, and I meet last Thursday discussed spectrometers and quadrupoles
2. Waiting on Ernie to finish the magnet design
3. Xiaqing will calculate field map from Beijing
4. Discussed fixed magnet option for quadrupole but preferred electromagnet
5. Thomas said the fixed magnet should still be considered in combination with electromagnet
6. Thomas is contacting a company about the fixed magnets
7. Need to have a magnet meeting where everyone is present not spectrometers Thursdays and quadrupoles Wednesday
ARIEL
1. Thomas said e-linac is running now with many tests until the end of month
2. Running at 30.8 MeV will go to higher power
3. Target test is currently envisaged for 3-5 August
4. Oliver said we need to have a written outline of the test plan and request beam time
5. Mike reported that Stan and Kate will also have an optical telescope and scintillator for background rate
6. Doug will send the updated test report and Thomas will make a beam request
Detectors
1. Michael said not much new for GEMs, able to use the LERF lab, using dry nitrogen, will also have a leak test
2. Mike reported on several advances on the trigger scintillator using cosmic rays and a source with a separate trigger detector
3. Tested 17 and 20 mm light guides got 600 ps end to end
4. Using direct coupling got 30-40% better pulse height
5. Likely will use the TRIUMF SiPM which maybe better than Hamamatsu
6. Looking at time over threshold rather than an amplitude measurement

6/27/22

General Meeting: https://indico.mit.edu/event/507/

Beginning the meeting with discussion about the wiki location.
1. Doug does not like the UX of the Github wiki, but the MIT wiki requires an MIT account to access
2. Ross volunteers to look into smoothly integrating images into the GitHub wiki
Doug
1. Raises discussion of the milestones made by Richard
  1. Have a technical design of the experiment by August, implemented in Overleaf
  2. How should we organize who writes what? Roughly aim to have the proposed institutional responsibilities guide the drafting
  3. Doug will implement a draft, and move the existing TDR report into a new Overleaf repo
2. Some kind of holiday next Monday, so we will cancel the meeting
Ross
1. Workshop
  1. Sent around draft call for proceedings to workshop organizers and it was approved, so now formally being sent to speakers
  2. Due August 1, as all Moore foundation money must be spent in the very early fall. Any delay jeopardizes being able to pay for late articles to be published
  3. Some discussion regarding hard and soft deadlines
  4. Likely will be fully published by mid-September
Kate
1. Overview of the simulation meeting
  1. Dean has set up MainzGen code and showed some plots indicating reasonable output of the generator
  2. In some cases coordinate systems are confusing
Doug
1. Had the first magnet meeting
  1. Didn’t get Harald, but had others
  2. Ernie is going ahead with Harald’s design, but with minor changes
  3. Aveen asked Harald to change pole shapes to be spherical, which better integrates into EPICS and design models
  4. Jan is concerned about space constraints
Aveen
1. Other users are present at ARIEL, so spending time in control room
2. DarkLight beam tests are currently scheduled for later July or early August
Doug
1. Thinking about going through the beam time authorization procedure for TRIUM to get on site for tests
Jan
1. DNP
  1. We should have an abstract submitted. Just one talk, not sure who will give it now, but will have several authors to choose later
  2. There is a CEU as well so we should send undergrads
Michael Kohl
1. Working with JLab to find a way to set up the detector in such a way that it is externally accessible
Mike Hasinoff
1. Getting a 600-800 ps timing resolution with existing scintillator
2. New scintillator ordered and will test shortly with Mainz board
3. Prepping for exam
4. Same scintillator as MUSE, so should have same signal rise time, likely board is not fast enough

June 16, 2022

General Meeting: https://indico.mit.edu/event/446/

Doug created an agenda for the meeting, but have a lack of attached presentations
Ross is still working on payment mechanisms at SBU for the workshop. Has identified a single person to approve the process
1. IOP has set up a link to submit conference proceedings
2. IOP require independent referee for proceedings, need someone outside of Darklight
3. Do we have a nominee for referee?
4. It is suggested we reach outside of SBU for a referee
5. Jan suggests a few names at MIT
6. Ross suggests someone at TRIUMF, maybe not on ARIEL
7. Maybe Rouven Essig? Knows Dark Matter from electron scattering
8. Ethan brought up the DarkLight proceedings and suggested adding everyone’s name to the proceeding as it is the first publication for this iteration of DarkLight. General agreement from the attendees.
Kate brings up timing of simulation meeting.
1. We agree to move to weekly rather than biweekly for simulation meeting
2. For new folks we are at a point where we understand the tools
3. Working on creating a limit plot using existing simulation tools
4. Jan has an additional student named Austin Colon who will be joining over the summer
5. Request for Ethan to add Slack invite link to minutes
  1. https://join.slack.com/t/darklight-hq/shared_invite/zt-1ay7gkc4z-owCq7QpadFyVWVW70u1lkQ
Magnet discussion
1. Ernie is on vacation
2. Harald is not present but Jan will speak to him in person tomorrow
3. Aveen wants a map of the field lines with some measurements
4. Harald slides are almost sufficient but missing a little bit of detail
5. Ross wonders if anyone from TRIUMF has had a chance to look at the magnet designs
  1. Aveen mentions Rick Bartman looked briefly and thought it looks reasonable. No obvious blocks for this design. Rick is head of beam physics department
Aveen mentions cryomodules are cooled down and planning some tests.
1. DarkLight tests planned in July
2. Does TRIUMF need extra hands for tests?
  1. Aveen does not think so
3. Need people more for the test experiment next spring
Michael says SSP module has been unpacked and equipped with optical transceivers in LERF lab. Has online zero suppression to alleviate VME readout of GEMS
1. GEMs could produce GB/s of data given how large they are. Zero suppression could reduce by factor of 5 to 10
2. Have FPGA based real time assessment of clusters and fired strips
3. Same as SBS program at JLab
4. Just starting commissioning, leak tests, etc.
Kate has been working on trigger detectors. Using Alpha-G system.
1. Not getting optimal timing. Working on offline corrections.
2. Currently at 1 ns resolution
3. Want to replicate Alpha-G performance before continuing
4. They measure the time resolution using cosmic rays and time difference from double ended readout. 15 cm long paddles, path length variation could be a non-trivial effect on resolution
5. Not using MAGIX board yet
6. System does also record pulse height. Attempted to correct for walk effect
7. Built in amplification is too big for signals, things get clipped at the maximum
Jan had a student who was interested in hardware, but is gone for the summer
1. Ross and Jan want to revisit the hardware at SBU when Jan returns
SNOWMASS discussion with Richard
1. Whole process was paused by COVID, but is restarting
2. Richard is a co-convener for accelerator BSM and precision physics searches
3. Richard can ensure DarkLight is mentioned in the document
4. Can include two page Letter of Interest into SNOWMASS if people are interested
5. Good to do in conjunction with conference proceedings
Doodle poll for next meeting
1. No time works for everyone
2. Monday 1-2 PM Eastern time is best, but missing Harald and Ernie
3. Thursday afternoon might be good, but miss some TRIUMF people
  1. Some schedules restricted by teaching responsibilities which change soon
4. Maybe we schedule a magnet design meeting and have them report back to group meeting
5. Likely will need to schedule a second doodle poll when semester starts
6. Moving to Monday at 1-2 PM Eastern time, but we will skip June 20th given short time scale
Doug will set up a magnet meeting
Doug set up another wiki to upload images
1. Hosted on MIT wikis
Jan and Ross will show how to upload images to GitHub

June 9, 2022

General Meeting: https://indico.mit.edu/event/425/

Discussed restarting the minutes. We will rotate responsibilities monthly, per vote of the attending folks. SBU will have the remainder of the month of June. Then it will move to MIT (and they can nominate the next victim, for now. We should move to something more formal afterward).
Yesterday, Richard led a discussion of the white paper we would like to add as a preface to the proceedings. Ross reports they will extend the paper lengths to 10 pages.
Ross will post Richard's slides from the editors meeting yesterday.
Jan has added the OLYMPUS generator to the suite of DarkLight repos -- it is not in our repo, but in the collaboration set.
Magnet: Ernie took the model from Harald and opened it, but was not able to extract what he needed. Once he has the pole and coil geometry, he can design the rest of the magnet, with the return yoke etc, that fits in the space allowed.
Ernie will iterate with Harald to get the magnet design moving
Harald reports on the thin quadrupoles: He showed slides with the magnetic field calculations and maps, which have ~1% octupole components when zooming in closely. (Ernie described a rule of thumb trick for proportions of pole gap to poletip radius (R=1.15*G)). Harald's slides also show that the resulting geometry allows the spectrometer magnet to get wthin 22.5º of the beamline without issue -- and, in fact, the quad can be moved much closer to the target if desired. He concludes with parameters of the current design. Step files are also available (link). Jan points out our ultimate target of 16º, and we should see if that can be achieved.
TRIUMF (Thomas?) will look at Harald's design from the slides above. If all is well, we can start discussing who will make these.
Aveen will implement Harald's design into the ARIEL optical lattice simulation and see how it performs.
Doug will resubmit the poll for a new meeting time, since many could not respond before many of the times were grayed out.
There was a request from Kate and Mike to fill in some info for the CFI process.

June 2, 2022

Resurrecting this...

September 30, 2021

General Meeting: https://indico.mit.edu/event/197/

Discussed the cabling needed to put some basic radiation monitors near the test chamber. 18.6 m shv cables are the longest folks in Canada have found. Doug believes we have a supply of 5m cables, but these are minimally helpful. Conservatively, we'd like a 50m cable.
The chamber and associated parts are in Washington state, waiting to cross the border (red tape).
Mike et al. couldn't get access to the area yet last week (linac group still running), but now there's the 1 month shutdown, so should have access next week sometime -- will be able to look at the cable routing. Richard asks for a video of the area.
Due to the Canadian holiday today, TRIUMF and SBU folks will push off their meeting on the administrative details of the workshop to next week, pending Jana's availability (vacation?)

August 19, 2021

General Meeting: https://indico.mit.edu/event/149/

Ross will email the organizing committee to begin a separate discussion.
Discussed the CFI grant strategy -- some discussion of how Darklight enables ARIEL upgrade and vice versa, funding-wise.
The SBU side of the Moore grant has been resolved save waiting for a final signature. Original budget is expect to be accepted per the grant specifications. Now we need to start convening the actual Organizing Committee.
Harald Merkel discussed the NINO readout board as it could be used to generate a high-resolution TDC. Readout through SoC FPGA/hybrid board, ~150$ per board.

August 12, 2021

General Meeting: https://indico.mit.edu/event/148/

Ernie will talk with Chris to get the changes to the magnet to match expectations.
Jim, Ernie, Thomas, and Ben will discuss offline (and before the next meeting )the details of what the target chamber needs to mate with.
Thomas will connect us with the group that has been using fiber optic detector instruments in the hall.
Bob Laxdal will forward information on the temperature monitoring for ISAC
NSF meeting on monday, Elena and Bill, seemed to go well. They cautioned against partial/split funding for postdocs for the possible complication of getting benefits etc. MIT gives full benefits if a postdoc is at least 50% funded. There was more follow-up discussion of how to most usefully split a post-doc across our institutions.
Xiaqing showed some changes to the coil design that were made (link). The changes Chris made to the coil and yoke don't match what Ernie expected to be done. Thomas points out that the asymmetry seen in the y direction is a natural consequence of a C vs H yoke. Ernie agrees, and notes other ways to compensate this. Some of these have been applied to this design, but not all. -thomas planche brought up the installation which we hope to do in the september shutdown. Some notes: Beam goes from big pipe to small pipe. Size of the exit pipe is smaller than the beam aperture in the beamline. Jim notes we can supply a different chamber if needed. Just needs dimensions from Thomas: His requirement is no less than 2" diameter pipes. Thomas wants to avoid any small apertures that aren't instrumented to detect beam loss. The resulting chamber wants at least one observation port so we can point an IR gun at the target. They'll assume 18" plug in length and 4" up-stream and down-stream flanging. They need also a bellows on one side, and a superstructure (what does the bottom look like?). Bates will provide a structure at the right height -- just need to know the beam height. -how well can ARIEL currently measure and control the beam? Radiation monitors, beam monitors, steering etc? They have a variety of measurements, including a DCCT -The SRF requires high cleanliness, so we may need to install fast-acting valves, need to consider how to trigger them, in order to prevent contamination fromk damage to the target etc that would force a shutdown, stripdown, and reconditioning. Beampipe is all taken to be UHV -- 10-8 scale or better. -regarding using a quartz window, Thomas mentioned they'd had a window shatter due to radiation damage. Ernie points out that pyrex glass is not vulnerable to that same failure mode, and fiber optic is also possible.
-Stan presented on magnetic field monitoring.

August 5, 2021

General Meeting: https://indico.mit.edu/event/147/

ACTION ITEMS:

Xiaqing will implement the solidworks model from Ernie this evening, then send the results to Jan so he can look at the impact the modified current has on the resolution. This was done, but the model was not what was expected, so they need to iterate.
Ernie will ask where the 1B detector ended up (if it was still mounted when they went to Bates). It was found at Bates.
Bobby is setting the 1B magnet to local control so that Ernie/Bates can run it (with a thermal camera) and see how much current it can accept.
In terms of an experiment early next year, we could use the 1B scintillator patch -- ~5cm x ~10cm?, high amplification, SiPM readout. Details would be in Charles Epstein's thesis. More likely we would like a gem stack from michael (he says march is tractable). Rita has expressed interest in general, but not in time for that test, probably. Mike Hasinoff will look into what is available at TRIUMF, but probably nothing large enough to fully cover.
We discussed also Jan's draft slides for the NSF discussion this coming Monday. One of the central questions from us for NSF is how to package a request for funding - as a single grant, or as individual institutions?
Postdoc sharing between an US and a Canadian institution is probably not practical.
The NSF meeting takes place at 3pm Eastern Time on Monday, Aug 9. The applications we make will depend on the outcome of that meeting (normal NSF deadline is December. These MRI grants are similar to a Canadian CFI )

July 29, 2021

General Meeting: https://indico.mit.edu/event/146/

ACTION ITEMS:

Jim Kelsey will put together a pack-and-go and send it to Bob Laxdal cc some other useful folks, to show the scattering chamber and target ladder
Ernie will reach out to his contact to ask about the right window to use to get accurate temp measurements from outside the vacuum.
Ernie will send Xiaqing a new coil design. Xiaqing will calculate the field, and then pass to Jan to update the resolution plots
NSF meeting coming up. Jan requests that we lay out exactly which groups are responsible for what.
We need to connect Bates eng. and TRIUMF eng still. Jim is on vacation starting shortly, but Joe Dodge should be invited to the next meeting. There is a separation at TRIUMF between accelerator and experiment physics, need some folks to help bridge that gap.
Bob Laxdal put together a preliminary shutdown sheet and submitted it. It needs to be updated with more information. Hopefully those details are not urgent.
Target ladder has a stepper motor that controls it, which can be done from the counting house. To read out temperature monitors etc we will need feedthroughs. Jim showed the chamber: Inlet tube is 3" diam, outlet is 1" diam. THere are a few mini-conflat (1.33"?) ports on the top of the chamber, alongside the ladder actuator. What is the right temperature sensor for this? The TDR contains the solution to the cylindrical heat problem. We discussed an IR/contactless interface. Need to make sure the IR light will pass through a window. ("7056 glass"?) Ernie knows this has been done at Bates -- but doesn't have a write-up handy -- of an infrared viewer that read out the temperature of a 600C crystal.
Foils are 1,5,10um thickness. Jim hasn't opened the box yet (presumably verrrrry delicate).
Xiaqing gave an update on the differences between Opera and Maxwell.
Discussion of the readout devices. Are we talking SiPMs or PMTs? Jan suggests amplifiers can come from MUSE, and TDC can be done on an FPGA. The particular readout/detector design should wait for the magnet design and dispersion to be closer to final.

July 22, 2021

General Meeting: https://indico.mit.edu/event/145/

ACTION ITEMS:

Bob Laxdal and Ernie Ihloff will discuss offline how to integrate the target: Who will provide the initial drawings, and who will return drawings with the interface specified.
TRIUMF will call a meeting when ready, to discuss with Bates engineers what resources (people) are needed to install the chamber.
Richard will send an email to Tomas (cc others) to lay out our intentions in order to get the plan for October moving (and reach the end-of-July deadline).
Doug will deliver the foils (which arrived recently) to Bates.

Harald Merkel would like to join the collaboration, and called in today. There was some discussion of what magnetic field simulation codes A1 uses.
Looking at when we would have to run the test experiment, and what should be involved. October, 2020 is the best time, since the next shutdown won't be until March. Vacuum chamber including a target ladder (with the foils) and temperature sensors would be a baseline. TRIUMF will need to see drawings of the chamber so they understand how to connect it, will need a description of what we intend to send. (interface to vacuum). TRIUMF uses MIDAS, though the 1B experiment ran with homemade software that was quite lightweight. For the October test, we would not expect to send a spectrometer magnet, just the scattering chamber, electronics, and various detectors to monitor backgrounds.
Bob Laxdal described the shutdown procedures: By the end of July (give or take a few days), TRIUMF needs the shutdown project sheet filled in. with drawings, scope of work, resources (people) required. This ensures that when equipment shows up, TRIUMF has the people and resources to receive it. He can put in a placeholder sheet into the shutdown project, but wants a better estimate of what is needed. The advice was to be minimalist in the plan, so that the review board does not choose to punt the installation to the March shutdown.
Canada is open for Americans to travel starting 9 Aug (and Canadians can come south starting 21 Aug). In a worst-case, we could ship the equipment and have Canadian collaborators manage the installation. If travel is possible and return is not in question, MIT will send people to guide/perform the installation. Jim notes that shipping has been particularly difficult lately, in terms of finding trucks and drivers etc.
We need to clearly define the test experiment (counting houses, electronics, DAQ, detectors...). This needs to be fleshed out in the TDR
Note that we need cables from detectors/controls to the 'counting house', in addition to having a counting house area defined.

July 8, 2021

General Meeting: https://indico.mit.edu/event/143/

Discussed stability and measurement of the magnetic field: Wwhat magnetic field stability do we need? How can we measure that? Ernie points out ~100ppm is very easy, current-wise. Stan Yen will write up something about how to measure field directly, at least from time to time, and about what we need in precision for our physics measurement, and what we can do to achieve that.
Xiaqing has ansys maxwell installed and is simulating the field in the magnet now. She showed the application and various slices of the field. The magnet design shows us that the fieldlines route to left and right of the centerline in the steel, which is what we would expect. Ernie says he has tricks he can apply to widen the uniform region of the field in the bore.
Ernie will give xiaqing some contacts to help with learning how to run the simulation -- there aren't good tutorials.
Ross gave a brief tour of the wiki, which you are reading here.

July 1, 2021

General Meeting: https://indico.mit.edu/event/142/ It is Canada Day, so some folks were not in attendance on the Canadian side.

From last week, Mike Hasinoff has been nominated/put forward as the lead investigator on the Canadian side, with kate as the second-in-command.  We discussed the CFI (Canadian Foundation for Innovation) grant that we believe someone has put forward. We're not sure who submitted, or what the context was, but DarkLight was referenced, per an email chain from Richard. That grant doesn't impact the test experiment, but only the The path forward is the same for us: We continue to plan for the test experiment, possibly this fall.
Bates folks worked to remove the detector equipment from HVRL. Everything is back at Bates now, though not yet sorted. Hopefully the field in the existing magnets can be measured in the next week, so we can make more quantitative plans for the test experiment.
Xiaqing Li worked on magnet simulations, now in a Win10 VM which she can run on her machine. She has been working on installing ANSYS on the VM, and has the physical dongle (but this didn't help with the installation). Probably an issue with the customer account. We reiterated wanting to involve TRIUMF in the magnet design. Rituparna suggests that they at least have codes they can share for the optimization.
There was more discussion of the rotating target, the danger that might pose, and hence a question of how much current we can have without a rotating target. Jim Kelsey suggests using a magnetic coupling to the rotating target, so there is no issue of a coupling. a high-vacuum rated motor is also possible, though Jim points out these are generally low torque.
We can put temperature sensors on the foil in the test experiment, to quantify the heating as we go. We might be able to defocus the beam., or raster/wobble in a known pattern that we can correlate to the bunches.

June 10, 2021

General Meeting: https://indico.mit.edu/event/121/

Jan discussed talks at a Heraeus conference: 8Be measurements being planned at INFN and elsewhere, and a recent Atomki carbon bump observation that might rule out axial vector coupling as a mechanism, though details are not yet available.
A discussion will take place on Monday, June 21, at 1pm to discuss responsibilities and next steps for the canadian side of funding.
Canadian travel still not clear, but should change/update on July 1.
Richard highlights upcoming conferences we should consider abstracts for: DNP, PANIC. He will put together an abstract. There is also a Canadian conference (CAP?) where TRIUMF has given a recent talk, but it isn't clear who gave it or if DarkLight was mentioned.
A proposal has been shared to use the PRad detector to search a similar parameter space.
We agreed to set up a github wiki to see if it meets our needs. (This is that.) Not clear how to upload materials beyond images.