Π polarizability Meeting Jun 1, 2022
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09:30 EST (JLab time) Weekly Meeting
REMOTE during Covid-19
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Meeting ID: 160 862 8791
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Elton Smith is inviting you to a scheduled ZoomGov meeting. Topic: CPP Weekly Meeting Time: This is a recurring meeting Meet anytime Join ZoomGov Meeting https://jlab-org.zoomgov.com/j/1608628791?pwd=bXhtZjdNRi8xeXZqWFh5T1R3TDBFdz09 Meeting ID: 160 862 8791 Passcode: CPP One tap mobile +16692545252,,1608628791# US (San Jose) +16468287666,,1608628791# US (New York) Dial by your location +1 669 254 5252 US (San Jose) +1 646 828 7666 US (New York) +1 669 216 1590 US (San Jose) +1 551 285 1373 US 833 568 8864 US Toll-free Meeting ID: 160 862 8791 Find your local number: https://jlab-org.zoomgov.com/u/acZK7hDWFf Join by SIP 1608628791@sip.zoomgov.com Join by H.323 161.199.138.10 (US West) 161.199.136.10 (US East) Meeting ID: 160 862 8791 Passcode: 112160
Action Items
-
Produce vertex distributions using MC to verify the software is be available for full/empty target commissioning (Andrew) </string> Plots have been produced but the reaction specification had a bug, so few entries were generated. Should work on next try -
Schedule training for FCAL Darkroom and Pb shield alignment (Elton)Training scheduled for Friday at 9:30.
Preliminary Agenda
- Previous CPP meeting: May 18, 2022
- Previous CPP Software meeting: Π polarizability Software Meeting May 5, 2022
- Announcements
- Action Items
- CPP-NPP Trigger (Sasha)
- CPP and NPP Run Conditions
- Photon beam / tagger / diamonds
- Software/Calibration, Simulations
- hdview2 event display
- MWPC Testing
- CPP and NPP Experiment Configuration
- DAQ and Electronic Setup (Sergey and Beni)
- Documentation (Elton and Simon)
- See List of Approved Procedures
- Description of FMWCP and CTOF for Shift Takers
- Tim has drafted a procedure to align the Pb picture-frame.
- Other business
- Next meeting
Minutes
Attending: Albert, Alex, Andrew, Beni, David H., David L., Elton, Eugene, Ilya, Sergey, Simon. [Note: I forgot to check on the participants list. Please add your name if it is missing].
- Previous CPP meeting: May 18, 2022
- Previous CPP Software meeting: Π polarizability Software Meeting May 5, 2022
- Announcements
- Run Coordinator Meetings
- Rory: At the collaboration meeting, Curtis suggested that we use 45/135 instead of 0/90 orientations. David H: At the Crystal Ball they moved from 0/90 to 45/135 because the detector had openings at 0 and 180deg, generating systematics with the 0/90 configuration. Alex: In 2016 we used only 0/90 and false asymmetries were seen because the beam was off center in the horizontal direction. We decided to use the 45, 45, 135, 135, AMO configuration. Elton will close the loop with Alexandre and Hovanes.
- Rory: How much should we change the beam current (photon flux) for the empty target runs, relative to nominal? Running at x2 nominal seems reasonable. Ilya: We should take a run at the full target current to check for systematics.
- Action Items
- CPP-NPP Trigger
- Sasha was not present
- Ilya: Reviewed data in raw mode taken in December. Initial rate estimates showed a 25% increase relative to previous studies (although under slightly different conditions). Plot of TOF pulses shows that increasing the threshold from 175 counts -> 400 counts, still low relative to minimum ionizing peak at 1000 counts, gives a rate back in line with original estimates. Beni: Goal of TOF calibration is to set the Landau peak at the same location for all counters (~ 800 counts). Noted that there are two thresholds: trigger threshold and readout threshold. The readout threshold should be lower than the trigger threshold in order to be able to easily monitor effect of trigger thresholds. Elton: What is the attenuation length? Beni: About 400 cm. Note the the (full length) TOF scintillators are 252 cm long -> Change in pulse height from center to edge is exp(-126/400) ~ 0.73.
- CPP and NPP Run Conditions
- Elton to update table based on previous discussions.
- Photon beam / tagger / diamonds
- Software/Calibration, Simulations
- hdview2 event display. David L: In the process of updating event display to show CTOF counters. Elton: If one filters on the trigger type, it might be easier to investigate BH muons.
- Vertex distributions. Andrew: Generated 500k e+e- BH events with Rory's generator. Only about 6 satisfied the reaction filter. (The problem was traced to the event filter definition).
- MWPC Testing
- FMWPC Log Book
- halldweb/talks/CPP_NPP
- Beni: FMWPC LV tripped, apparently due to DIRC interlock that shares a common crate. This needs to be sorted out. Beni will contact Nick.
- Data taken with the CTOF trigger can be useful in checking data, even with cosmics. CTOF FP trigger does not show up in monitoring plots. Alex will update plots to histogram CTOP bit 6 (counting from 1).
- CPP and NPP Experiment Configuration
- Andrew: Path to recent BH e+e- events has been added to the list of MC files.
- DAQ and Electronic Setup (Sergey and Beni)
- Documentation (Elton and Simon)
- See List of Approved Procedures
- Description of FMWCP and CTOF for Shift Takers
- Tim has drafted a procedure to align the Pb picture-frame. Elton needs to add this to the shift-taker's page.
- Other business
- Next meeting