Energy Calibration in Each Target

To get the corresponding energy per bin in each target histogram, following methods are used:

With PIBEAM trigger, fill fastbus ADC from each piece of target into 9 individual histogram. From each histogram, the energy range corresponding to a pion stop in that target was extracted.
With information obtained above, pick out events meetimg following cuts:

   (trig[0] & TRIG_PI_BEAM)    &&                           
   cadc[306+i] < tgt_high[i]   && 
   cadc[306+i] > tgt_low[i]    &&   
   fabs(dtim[280+i]) < 3.      && 
   daps[280+i] > 5.
Fill DADCs which was the peak closest to the trigger timing into DADC histograms. the peak around 400 bins is due to energy deposited by stopped pions.
Fill DAPSs which was the peak right after the pion-stop peak, in this case most of them are muons, into DAPS histograms. The peak at around 40 bins should be corresponding muon peak. After fitting the muon peak, the energy per bin is obtained for each piece of target.
To be convincing that we picked out the muon peak, we also calculated timing difference between pion peak(DTDC) and muon peak(DTPS), results were put into histograms.

Runs used to get above histograms are run36560-run36569(execpt 36562). Energy per bin for each piece target is listed below

TGT # Muon peak in bins Mev/bin
0 78.20 0.0345
1 37.763 0.0715
2 44.154 0.0611
3 42.086 0.0642
4 48.872 0.0552
5 47.071 0.05736
6 94.613 0.0285
7 103.83 0.0260
8 54.321 0.0497

Summary

After using the new waveform.dat taken from run36803, the fitting results are much better, which can be examined from the timing histograms.

© January 20001. by Weidong Li for PIBETA collaboration.