Parameter files - ATTPC/ATTPCROOTv2 GitHub Wiki

There are a number of experiment/detector specific parameters that need to be specified for the code to properly function. There are all set in a parameter file and managed by the class AtDigiPar. NB: Some of the names are a bit misleading, in particular ZPadPlane and TBEntrance, due to historical reasons. Please pay attention to the comments in the example file below which describe the physical meanings of the parameters.

Setting the parameter file

FairRuntimeDb *rtdb = run->GetRuntimeDb(); // run is type FairRun*
FairParAsciiFileIo *parIo1 = new FairParAsciiFileIo();
parIo1->open("path to parameter file", "in");
rtdb->setFirstInput(parIo1);
rtdb->getContainer("AtDigiPar");

Example Parameter File

################################################################################
# Parameters used throughout ATTPCROOT software
# Format:
# parameter_name:parameter_type(Int_t-integer, Double_t-double) parameter_value
# AtDigiPar
# Description of parameters
################################################################################
[AtDigiPar]
EField:Double_t               70000   # Longitudinal E-Field [V/m]
BField:Double_t                0.0   # Longitudinal B-Field [T]
TBEntrance:Int_t               455   # Beam position at detector entrance in TB. The detector enterance is the side opposite the Pad Plane (regardless of orientation)
ZPadPlane:Double_t          1000.0   # Position of the micromegas pad plane w.r.t the entrance. In other words, the length of the detector. [mm]
EIonize:Double_t             42.70   # Ionization energy of gas (w-value) [eV]
Fano:Double_t                 0.24   # Fano factor of the gas
CoefL:Double_t              0.0055   # Longitudinal coefficient of diffusion [cm^2/us]
CoefT:Double_t              0.0038   # Transverse coefficient of diffusion [cm^2/us]
DriftVelocity:Double_t        0.82   # [cm/us]
Gain:Double_t                 1000   # Average gain of micromegas
SamplingRate:Int_t             3.125 # [MHz]
GETGain:Double_t              1000   # Gain of the GET electronics [fC]
PeakingTime:Int_t              720   # Electronic peaking time [ns]
################################################################################