Jul 16, 2015 Calorimetry
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Contents
Video Conferencing Information
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
Action Items
- Change BCAL and FCAL coordinates use the global coordinate system (not the target center). Action of this item is under discussion
-
Understand BCAL efficiency estimates (cluster vs enhanced) for m7 and m8 data taking modes (Ahmed)Under active study -
Provide feedback to Will on shower fragmentation (All) -
Modify mcsmear to produce digihit outputs (Tegan)Completed and checked in.
References
Tentative Agenda
- Announcements
- Time for meeting
- Action Items
- FCAL Update
- BCAL Update
- Calorimetry F250 Firmware Discussions
- Reconstruction and Simulation
- Early look at BCAL Clusters https://logbooks.jlab.org/entry/3346051
- Calibration
- Any other business
- Testing
Minutes
Attendees: David, Elton, Jon, Manuel, Mark, Adesh (JLab); Zisis, Ahmed (UofR); Sean (NW); Curtis, Will, Mike (CMU); George (Athens).
- Announcements
- Start meetings at 11 am, including BCAL reconstruction meeting.
- Action Items
- FCAL Update
- Base / firmware (Jon)
- Updated all firmware and testing on a single strand. Waiting for feedback from Hovanes, which will take about a week.
- Will need to decide on a timeline and criteria for replacing poor performing bases. There are about 10 that need to be checked.
- Before changing any hardware, the new firmware will be updated and problems verified.
- FCAL efficiency (Jon)
- Starting to study exclusive omega p event with omega->pi0 gamma for determining FCAL efficiency
- Gain calibration. See Log Entry 3346084 (Adesh)
- Gain calibrations (in ccdb) were determined by minimizing the pi0 width using B=0 runs
- Nonlinearities (i.e. variation in pi0 mass with energy) were observed
- Approximate nonlinearity corrections were added to ccdb, but were ineffective, so they have been backed out.
- This calibration applied to B=not 0 runs result in a pi0 peak ~ 117 MeV, sigma~9 MeV.
- An electron sample from the B=not 0 runs were used to determine gain constants for 20 < r < 60 cm, and used as a see for further pi0 width minimization. See Log Entry 3345736. The iteration used B=0 runs.
- Output shows non-linearity for B=0 runs. However, non-linearity is not apparent in the B=not 0 runs.
- Zisis: Suggest to limit range of fit of two-photon distribution to better reproduce the pi0 peak.
- -> It appears that the B=0 and B=not 0 runs have different systematics
- Eugene suggested yesterday to take LED data while ramping the magnet to assess the influence of B field on the pmt response.
- Will: Suggests to start the pi0 width minimization with the pi0 peak centered on the physical mass. It could be that the fit is being because of the wrong overall normalization.
- Elton: No pi0 peak is visible in the 500<E<600 MeV photon bin. Why not, and is it due to trigger thresholds. Need to understand this to better plan for more calibration runs next period.
- Base / firmware (Jon)
- BCAL Update
- Time-walk (Zisis for Noemi)
- Noemi has had some issues with generating timing plots. Versioning of gcc, Jana, etc have been resolved, but still nominal monitoring plots show a lack of entries. They are investigating if there is a problem with scale and events falling outside the nominal range.
- Mark had sent early analysis of timing using LED data. Zisis asked if he used the unified hit quantities? Mark: Could not remember precisely, but thought he might have taken the data from DAQTree, but they should work with unified hit objects.
- Time-walk (Zisis for Noemi)
- Calorimetry F250 Firmware Discussions
- Reconstruction and Simulation
- Early look at BCAL Clusters https://logbooks.jlab.org/entry/3346051
- digiHits (Tegan)
- Checked in digiHits, so that MC should now produced these objects.
- Elton: The e-mail implied that with the new code the resulting MC showers would have a gain that was about 3 times too large.
- Tegan agreed to update the variation=mc of gains to yield the (approximately) correct energy scale. [Note already completed. See e-mail]
- Calibration
- Any other business
- Testing