May 28, 2020 Calorimeter
Meeting Time: 11:00 a.m.
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Participant Direct Lines
- JLab Phone in CC L207 is 757-269-7084 (usual room)
- JLab Phone: in CC F326 is 757-269-6460
- Phone in the Regina Video-conference Suite is 306-585-4204
- Athens Phone: in Christina's office is 011-30-210-727-6947
- FCAL HDFCAL log book
- BCAL HDBCAL log book
- Calibrations: 2020 Data Production; RunPeriod-2019-11 Validation; Offline Monitoring Data Validation
Goals for Calorimetry Group
- Determine preliminary photon reconstruction efficiencies as a function of E, phi and theta in data and simulation with a point-to-point precision of at least 5%.
- Measure systematics of pi0/eta mass calibration as a function of detector position to a precision of at least 5 MeV.
- Demonstrate agreement of photon reconstruction efficiency and resolution between data and simulation as a function of E, phi and theta to within 5%.
- Check switches on FCAL board with high scaler rates and make sure it is set to 2 V full scale. (Colin and Sasha)
- Long term items
- Action Items
- Run Updates
- BCAL LED (Varun): Monitoring Update 
- BCAL (offline)
- FCAL (offline)
- Photon efficiencies for different run periods
- Any other business
Attending: Igal, Mark, Varun, Zisis, Tolga, Jon, Elton, Christina, Colin, Sasha, Churamani, Karthik, Sean, Matt, Susan
- Director's newsletter and MEDCON5 plans: https://www.jlab.org/div_dept/cio/cni/all_hands/May-26-2020-AllHands.html
- Run: 6 hour shifts with local people: Lab staff plus others in the viscinity, following a 15 day quarantine if they have travelled.
- Action Items
- Keigo presented at the Collaboration meeting. Things have been very stable since Mike S. did his study. This action item is considered closed.
- Sasha will undertake trainiing from Colin for FCAL bases. There is a Wiki page and Colin is updating documentation by Adesh and Jon. This is a short-term solution. A senior person should be tasked with FCAL oversight. This should be brought up with Eugene.
- Run Updates
- Inner base status Inner base map to show ones in good condition/repaired, ones needing attention and some not found in JInventory. This work will happen in the fall. Sasha mentioned the need for better alignment.
- Log Entry 3810885 (Nick Sandoval) Chiller alarms where a communications issue that is being resolved. At our next CALWG meeting we will go how to turn things back on when the time comes.
- FCAL (Igal - PrimEx):  Gain matching with focus on outer rings. Clear pi0 peak (Ilya's method) w/o tracking. Matt: look at plots with old calibration constants to verify the size of the effect. Recalibration is done every 8 days, moving to 4 days. Eta peak position changes w.r.t. pi0 peak possibly due to threshold. Matt: change 5 MeV threshold in HG4 and recompile to study this. Bug in FCAL factory went undetected because it is small, but still worth looking at this. Matt: no good mechanism was found to study these effects in data at low energy.
- BCAL (Karthik - PrimEx): Nonlinearity Update Monitoring plots show an increase in the pi0 mass value at higher energies. Ask Alex A about vertex in these skims. Igal: iwas this studied versus polar angle? Karthik: no. Mass ratio shown for symmetric photons (adequate stats up to 2.5 GeV). Emax/Emin method probes higher energies. Primary source of nonlinearity after SiPM saturation correction is leakage; this can be modelled. Nonlin method may over-correct at higher energies for PrimEx. Elton summarized the non-linear function and process based on the J/psi results from ~2 years ago. MC is better now, more stats, perhaps we should revisit this. Mark: we should be suspicious as electron radiation not taken into effect. Sean cautioned using the monitoring plots and fits (3rd order pol for background). These are a red heering and the monitoring plots should be fixed so as not to mislead people. Next meeting: Mark will report on his simulation studies and energy correction.
- BCAL LED (Varun): Monitoring Update  Slide 3: each point is a fit of the time variation. The plot shows an azimuthal variation. Checks: i) make sure that jump in 150-250 nA is not due to tuning runs. ii) check continuity from module 48 back to module 1. Mark: effect is ~2%, but we are looking at 1% on the non-linearity; if we divide into batches we will have ~0.5% effect per batch. Mark will look more carefully at the up/dn ratios. Sean: take a constant set of gains (from pi0) and compare batch 2 to 8 (all 350 nA runs).
- BCAL (offline): new batch/plots available soon.
- FCAL (offline): new batch/plots available soon.
- Reconstruction: nothing
- Photon efficiencies for different run periods: Sean: apply studies to 2018 data sets. Matt/Jon are redoing Jon's FCAL efficiency study. Elton will pass his costheta_cm code to someone else (maybe contact IHEP again).
- Comparing simulation and data (Colin) Deferred to next meeting.
- Any other business