Jun 4, 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)
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- Athens Phone: in Christina's office is 011-30-210-727-6947
Action Items
- Keep events reporting z outside the BCAL physical boundaries in the "curvature" reconstruction (Tegan)
- Change BCAL and FCAL coordinates use the global coordinate system (not the target center) (who?)
- Understand BCAL efficiency estimates (cluster vs enhanced) for m7 and m8 data taking modes (Ahmed)
References
Tentative Agenda
- Announcements
- Action Items
- Summer plans
- Power Outage in Hall D (Tim)
- Shutting power down (Fernando)
- FCAL Update
- BCAL Update
- F250 firmware discussion
- Reconstruction and Simulation
- pi0 peak reconstruction (Tegan)
- Calibration
- Any other business
- BCAL - Radial Dimensions (George)
Minutes
Attendees: Elton, Matt, Mark, Adesh, Manuel, Will (JLab); George (Athens); Sean (NW); Noemi, Ahmed, Tegan (UofR).
- Announcements
- Action Items
- Summer plans
- Power Outage in Hall D (Tim)
- Shutting power down (Fernando)
- FCAL Update
- FCAL studies of Pedestal and Pulse Integral (Manuel)
- See Log Entry 3342815
- Study of pedestal widths depending on number of samples, either in a single event or over multiple events
- Consider using a rolling average (using multiple events)
- Data set from last summer taken at about 100 Hz
- Finds variation of peak/peak ~ 1.5 %.
- Sean: Studies of optimal NSA should look at beam data, since pulse shapes may be different between pulser and physics data.
- Elton: Should look at the pulse height variation of the widths.
- Calibration (Adesh)
- Working on plugins, but debugging in progress
- Goal is to create pi0 and electron skimmed files with ROOT trees for ease in calibration
- Other
- Jon is working on firmware for bases.
- FCAL studies of Pedestal and Pulse Integral (Manuel)
- BCAL Update
- LED bias scans (Mark)
- Completed analysis of bias scans.
- Some interesting results. Results depend (very slightly) on which LED side the pulser is flashing.
- At the Vover=0 V we still measure a small signal (~5% of nominal) indicating that the break down voltage is not precisely set (to within about 50 mV).
- Estimating the gain changes between the fall and spring run gives (T=18 deg V=1.2 / T=10 deg V=1.4) ~ 0.73. The ratio of gains determined by Will using pi0s gives a ratio of 0.69. Consistency is within 6%. The remaining difference might be able to be explained by temperature changes of the LED and could be investigated by taking data with opposite sides set a different temperatures. However, in practice we will need to calibrate with data at the settings of the experiment, so detailed understanding of these systematics are probably not necessary.
- LED bias scans (Mark)
- F250 firmware discussion
- Reconstruction and Simulation
- pi0 peak reconstruction (Tegan)
- Comparison of mcsmear output using original and updated code.
- Comparison is reasonable, but differences remain.
- Pi0 peak for both reconstructions is at about 100 MeV. Suggested that variation=mc for ccdb should be used. [Note added: Tegan already made new plots with this setting and indeed peaks went up to about 120 MeV]
- [Note added] Elton: At this point, the comparison between new/old is not as important as understanding how the generated energies in geant are propagated to simulated hits with new code.
- Efficiencies (Ahmed)
- Trying to investigate differences in efficiencies between mode 7 and mode 8 by targeting events which are not reconstructed
- Finding some inconsistencies between hdview2 and analysis, which needs further investigation
- Calibration
- BCAL - Effective Velocities and Time Offsets (George)
- Good progress. Systematic differences between layers is notable, but is smaller for cosmic-rays compared to beam data.
- Sean: Mike Staib is working on CDC alignment, and may have useful tracking updates
- Will: Could consider using beam data with B=0 for comparison to cosmic runs
- Elton: Concern that there is bias when choosing the radius of intersection for track based on the measured value of z in shower.
- First report on time offsets between upstream and downstream, which are close to zero.
- Any other business
- BCAL - Radial Dimensions (George)
- Differences found in the geometry between different ways to access them. Elton will check with David L.