SoLID Ecal Weekly 20230727

SPD Timing discussion

Carter showed his slides from previous week. SC_C - SC_D seems reasonable. See comparison table at SPD page, 2nd table from top. Note that HRS S2 was 50mm thick and had ~300ps resolution. Scale by 1/sqrt(Npe) or 1/sqrt(thickness) we expect 474ps for the 2-cm thick scintillators we are using. (This also means our PMT might have better "Transient Time Spread(TTS)" than the S2 PMTs.
For LASPD timing, should plot (T+B)/2 minus another scintillator.
Mike will post PMT information soon

from previous week, it was obvious that MIP for Shower shifted to higher values for high rate runs. Pulse deconvolution might help
- Mike will check with Jixie on the code and technical note availability. The note should contains the 2 simpler options (fixed vs. dynamic pedestal subtraction, no deconvolution). Perhaps co-writing the note?
Ye showed 10uA run comparison throughout the 18-deg run period and the MIPs remained stable
Jixie's pedestal study (on redmine) is without beam. Did we have one with beam?
Ye showed SC-B pulses and it had significant higher rates and baseline shift than front scintillators. (SC-B had no beam-side shielding.) THis is okay if we want to cut on half-MIP, just need to shift the MIP position accordingly.
For longer term we need to simulate pulse shape in SoLID full sim. This will give us: baseline shift, timing, etc.