ic overview - SpiRIT-Collaboration/BeamAnalysis GitHub Wiki

The Ion chamber is used to determine the charge. The energy deposited in the ion chamber scales with Z. To properly calibrate this, the AoQ ratio must be approximately calibrated (set by the TOF offset).

The Ion Chamber requires 4 values to be set, and this changes for each beam. We fit the energy lost in the ion chamber using a linear fit , with ch2mev_0 the offset and ch2mev_1 the slope: ICMeVSqSum=ch2mev_0+ch2mev_1*ADCSqSum

I used ICfitting1.C to find the ADCSqSum for different isotopes, and then used LISE++ to determine the actual energy lost. From that information I manually fit the information together using LINEST in Excel.

After the energy loss has been calibrated, we have to find Z as a linear fit to a function of ICMeVSqSum and beta(the function can be found in standaloneICCalib.C).

Z=zcoef_1+zcoef_0*f(beta, ICMeVSqSum)

standaloneICCalib.C can be used to determine these parameters, and it attempts to do so automatically. The user may need to do some changes to their macro, including adjusting the range of "histICMeV" to have correct peaks.

Within the 112 Sn setting, I have observed that early runs do not match later runs, but I have not created multiple IC files for this setting. The IC configuration should work for the majority of 112 Sn runs.