Objective
At the first beamtest workshop in Pisa in March 2006, I (=Dave Smith) presented 5 studies that the CAL experts (=mainly Sasha Chehtman) thought should be done. You can flip through http://glast.pi.infn.it/glastdocs/cernbeamtest/workshop/slides/CALstuff.ppt
The five studies are
1) excercise the FHE triggers in realistic conditions and quantify their response ;
2) Check and refine the intercalibration of the Lex8, Lex1, Hex8, Hex1 ranges ;
3) Verify the performance of the autorange feature (ULD circuit) ;
4) Study how the non-linearity corrections obtained using charge injection data fare when applied to scintillation signals ;
5) Quantify the pedestal recovery after large charge deposits in the photodiodes ;
Here is who is doing which:
(1) & (3) are being pursued by Tomi & Jan, with Thierry, Denis, & Dave kibbitzing heavily.
(2) is well underway by Fred & Thierry and will appear at https://confluence.slac.stanford.edu/display/BeamTest/Calibrations.
(4) & (5) require large energy deposits and are primarily SPS studies, even though a PS pre-study would be useful, given that time may be tight at the SPS. Denis may undertake (5), to be confirmed.
As these studies mature they will hopefully spawn separate pages. For now, the rest of this page is for (1), the FHE trigger study.
Data Taking Configurations and Relevant Runs
The FHE trigger study requires TEM diagnostics to be ON and a high energy beam to deposit lots of energy. Further, we need a series of at least 3 different energy FHE discriminator settings files. 0.5, 1, and 2 GeV would be good. Johan Bregeon will prepare these. For his 1 GeV examples see http://www.slac.stanford.edu/exp/glast/ground/LATSoft/nfsLinks/u37/BeamTest06/rawData/700000770/latest_G15_MeV1000_fhe_CAL_FM101.xml
I'm not sure how much statistics we'll need... Nota bene, as of this writing we have yet to see FHE fire at the PS testbeam! The above settings files went in for only run 770, taken with 5 GeV electrons this afternoon, and no CAL HI triggers were recorded. Other urgencies have precluded our making progress on this...
Predictions from MC Simulations
My Geant 3 simut 4
Possible Experimental Backgrounds
In the attachment
Results and Discussions
In the attachment