Jan 29, 2015 Calorimetry
Revision as of 13:44, 30 January 2015 by Zisis
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Meeting Time: 11 a.m.
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Participant Direct Lines
- JLab Phone: in CC F326 is 757-269-6460 (usual room)
- JLab Phone in CC L207 is 757-269-7084
- Phone in the Regina Video-conference Suite is 306-585-4204
- Athens Phone: in Christina's office is 011-30-210-727-6947
- Collaboration Meeting February 19-21 at Jefferson Lab.
- Action Items
- FCAL HDFCAL log book
- BCAL HDBCAL log book
- Reconstruction and Simulation
- Any other business
Attendees: Matt, Manuel, Adesh, Will M., Mark D. (JLab, Ahmed, Tegan, Noemi, Andrei, Zisis (Regina)
- Announcements: Noemi arrives in NN on Sunday, Feb 1. She will come to the A-wing on Monday to meet with GlueXers. Her main task is to run cosmics for the month. The BCAL Group will have a meeting early next week to plan details.
- Collaboration Meeting February 19-21 at Jefferson Lab; Zisis slotted two 45 min talks. Tentatively, Matt will give the FCAL and Mark the BCAL one.
- Action Items: none! Shocking. Actually, many things are in flux and in progress so this is why we do not record them as Actino Items.
- FCAL HDFCAL log book: There is a sizable task list for the FCAL, presented below by Matt.
- Switching noise: Discussion took place with Sascha to determine if this noise impacts the trigger. At low energy threshold it is best to use the FCAL-START trigger to minimize the noise. Going to compressed mode may help. Sascha is also investigating a mysterious class of events.
- Impact of noise on physics quality. IU is skimming pure events (real gamma in pi0 peak) and looking at clusters to get the probability of noise in those events. Cosmic runs can help as well, by providing events that mostly contain noise.
- Peak-finding algorithm in FADC: is it good enough? Are there pathologies? Again, look at good cluster samples (pi0) and search for clusters or blocks way out of time.
- Adesh has looked at the pedestals over all runs. No drifts observed (except in 1 run, which is under investigation). Decision is to use set pedestal values and perform periodic spot checks to make sure things do not drift.
- PMT bases. About 60 of them started to draw more current, leading to sagging of the HV on the bases. IR camera shots revealed no hot spots. Most of these 60 are from the first production run of 500, that were made by the vendor and had issues mostly connected to dirt on the components before the conformal coating, and the dirt may becoming conductive. A sample of the bases will be sent to Paul Smith for evaluation. We have 200 spares for FCAL, so these could be cycled through if necessary.
- Work on the control system with Hovannes. Issues will be separated in critical ones and longer term ones (firmware).
- John at IU continues to work on the energy calibration. Matt provided him with skimmed two-track pure pi0 events with good purity (as verified also by Justin), and John is seeking the optimum cuts for the calibration.
- BCAL HDBCAL log book
- Mark is working on the timing of independent channels, to determine if we need individual channel timing offsets, and if yes, what should be the procedure to determine them. By looking at showers, Mark sees that the time of hit to average cluster time exhibits large differences, for some channels, dependent on layers: tails go one way for the inner layers and the other way for the outer ones. Perhaps this is related to the "shower curvature effect". Some weird double peaks appear as well. Work in progress.
- Will M is running Tegan's pedestal plugin on all runs, and this should be done by the end of the day. He is also working with John at IU on the energy-gain calibration with the view to apply the method to the BCAL. Work in progress.
- Noemi and Andrei are ready to start cosmics runs on a BCAL prorotype at Regina, aiming to investigate reflections at the ends of the module. Irina is preparing to rerun the cosmic simulations using the attenuation lengths extracted by Mark. Mark will provide these in an ascii file on the logbook.
- Pedestals: Values Media:Modules-1-48-UD-PED.pdf, Sigmas Media:Modules-1-48-UD-SIG.pdf. Just like for the FCAL, the BCAL pedestals are very stable. See attached plots.
- Reconstruction and Simulation: nothing to report.
- Calibration: see above.
- Any other business: none.