Difference between revisions of "Jan 11, 2018 Calorimeter"
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# Announcements | # Announcements | ||
+ | #* BCAL paper submitted to NIM. It is also on the archive at [https://arxiv.org/abs/1801.03088 https://arxiv.org/abs/1801.03088] | ||
+ | #* Accelerator is running a couple of days ahead of schedule. Shifts are being taken by local volunteers. | ||
# Action Items | # Action Items | ||
# FCAL Update | # FCAL Update | ||
## Run preparations | ## Run preparations | ||
− | ## | + | ##* [https://halldweb.jlab.org/wiki/index.php/File:Screen_Shot_2018-01-09_at_11.50.59_AM.png FCAL Health] |
+ | ##* On Tuesday, all bases were on and at voltage. There are now a few bases that are sagging. | ||
+ | ##* LED data shows 2 dead channels. The bases and pmts were replaced. Matt: The only pmt failure is due to loosing vacuum, which can be seen by visual inspection when the copper-colored cathode disappears.Colin: At least one pmt had lost the photocathode. | ||
+ | ##* There was a discussion of "hot channels" that could affect trigger performance. Colin will check with Sasha to get a list. | ||
+ | ##* Discussed a threshold scan for the FCAL to see if the readout threshold can be lowered. Time to do this test was scheduled for late in the afternoon. [Note added: Colin took the data last night] | ||
+ | ##* The pedestals needed to be set before the scan. [Note added: Serguei set the pedestals for all FADCs (except start and TOF) at noon]. | ||
+ | ##* Comment: We should setup a systematic time to reset pedestals (e.g. on maintenance days). | ||
+ | ##* LED script to cycle through FCAL configurations (3 colors and 2 voltages) is operational (Mark). | ||
## Other updates | ## Other updates | ||
+ | ##* Monitoring plots for FCAL (pi0 peak). Colin will work with Thomas to make the existing plot more useful. | ||
# BCAL update | # BCAL update | ||
## Run preparations | ## Run preparations | ||
+ | ##* BCAL has been setup with the same parameters as last spring: chiller at 5 deg C, 1.4 V overbias, LED configurations cycling at 10 Hz. | ||
+ | ##* Zisis: It would be useful to take some dedicated LED data during the maintenance day for dedicated checks. | ||
+ | ##* Zisis: What is done about the poor quality channels from last spring. Elton: The main problem was fixed (loose cable connection). The others had some shifts in their gain by a few percent sometime during the run. We haven't done anything special, but we should check on them when the data come. | ||
## Other updates | ## Other updates | ||
# Calibrations | # Calibrations | ||
# Reconstruction and Simulation | # Reconstruction and Simulation | ||
+ | ## [https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3500 FCAL Energy Resolution Study] (Cristiano Fanelli) | ||
+ | ##* Cristiano showed pi0 MC and data and showed that the distributions were consistent with the expectations from energy and angular resolution. | ||
+ | ##* Matt: The angular resolution is taken from MC and could contribute significant systematics to the energy resolution extracted at large energies | ||
+ | ##* Elton: The distributions are compared to 5.7%/sqrt(E) + 3.5%. Where did these values come from? Matt: The schocastic term is taken from RadPhi adjusted for increased light collection in the present FCAL. The floor term is a conservative estimate for contributions from calibration accuracy. | ||
+ | ##* Elton: It appears that the flat behavior that was seen in the Fcal energy resolution may be explained by the angular resolution term. Colin: It is also the case that the pi0 peaks extracted for high energy may suffer from poor fits to peak and background. | ||
+ | ##* Notes added by Zisis (Elton had to go to his shift): A discussion took place on whether Cristiano’s analysis should be attempted on inclusive pi0. Matt stated that CF’s method is the best way to measure the width (background manageable) . The old FCAL plots on slide 6 were a decent early attempt, but CF’s method gives more robust results. Christina asked about the opening angle between two photons at 4 GeV and Matt said that it is 2.5 deg; Cristiano added that his cuts that the two photons have angles greater than 2 deg and be apart more than 12 cm eliminates extreme opening angle events. | ||
# NIM articles | # NIM articles | ||
# Any other business | # Any other business |
Latest revision as of 17:21, 12 January 2018
Contents
Video Conferencing Information
Meeting Time: 11:00 a.m.
- To join via a Web Browser, go to the page [1] https://bluejeans.com/907185247.
- To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 907185247.
- To join via phone, use one of the following numbers and the Conference ID: 907185247.
- US or Canada: +1 408 740 7256 or
- US or Canada: +1 888 240 2560
- Upon connection all microphones are automatically muted. To unmute your mike on a Polycom or equivalent unit, enter *4. Unmuting on a computer is trivial as there is a microphone button than can be clicked.
- More information on connecting to bluejeans is available.
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
Action Items
- Check in the code, including scripts, that is used for recent calibrations into git (BCAL: Mark)
- Add monitoring plots for charged particle clusterizer [Will to suggest plots and collaborate with Mark]
- Checks of MC calibrations for BCAL. Timing (Sean and Mark), non-linearities (Will)
Complete after new launch
- Report back on study of eta with in FCAL [Mark]
- From Mike's work: -cos(phi) type dependence in the data and a phi dependence at the downstream end of the bcal
References
- FCAL HDFCAL log book
- BCAL HDBCAL log book
Tentative Agenda
- Announcements
- Action Items
- FCAL Update
- Run preparations
- Other updates
- BCAL update
- Run preparations
- Other updates
- Calibrations
- Reconstruction and Simulation
- NIM articles
- Any other business
Minutes
Attendees: Elton, Colin, Mark (JLab); Matt (IU); George, Christina (Athens); Andrei, Zisis, Ahmed (UofR); Sean (FSU); Cristiano (MIT).
- Announcements
- BCAL paper submitted to NIM. It is also on the archive at https://arxiv.org/abs/1801.03088
- Accelerator is running a couple of days ahead of schedule. Shifts are being taken by local volunteers.
- Action Items
- FCAL Update
- Run preparations
- FCAL Health
- On Tuesday, all bases were on and at voltage. There are now a few bases that are sagging.
- LED data shows 2 dead channels. The bases and pmts were replaced. Matt: The only pmt failure is due to loosing vacuum, which can be seen by visual inspection when the copper-colored cathode disappears.Colin: At least one pmt had lost the photocathode.
- There was a discussion of "hot channels" that could affect trigger performance. Colin will check with Sasha to get a list.
- Discussed a threshold scan for the FCAL to see if the readout threshold can be lowered. Time to do this test was scheduled for late in the afternoon. [Note added: Colin took the data last night]
- The pedestals needed to be set before the scan. [Note added: Serguei set the pedestals for all FADCs (except start and TOF) at noon].
- Comment: We should setup a systematic time to reset pedestals (e.g. on maintenance days).
- LED script to cycle through FCAL configurations (3 colors and 2 voltages) is operational (Mark).
- Other updates
- Monitoring plots for FCAL (pi0 peak). Colin will work with Thomas to make the existing plot more useful.
- Run preparations
- BCAL update
- Run preparations
- BCAL has been setup with the same parameters as last spring: chiller at 5 deg C, 1.4 V overbias, LED configurations cycling at 10 Hz.
- Zisis: It would be useful to take some dedicated LED data during the maintenance day for dedicated checks.
- Zisis: What is done about the poor quality channels from last spring. Elton: The main problem was fixed (loose cable connection). The others had some shifts in their gain by a few percent sometime during the run. We haven't done anything special, but we should check on them when the data come.
- Other updates
- Run preparations
- Calibrations
- Reconstruction and Simulation
- FCAL Energy Resolution Study (Cristiano Fanelli)
- Cristiano showed pi0 MC and data and showed that the distributions were consistent with the expectations from energy and angular resolution.
- Matt: The angular resolution is taken from MC and could contribute significant systematics to the energy resolution extracted at large energies
- Elton: The distributions are compared to 5.7%/sqrt(E) + 3.5%. Where did these values come from? Matt: The schocastic term is taken from RadPhi adjusted for increased light collection in the present FCAL. The floor term is a conservative estimate for contributions from calibration accuracy.
- Elton: It appears that the flat behavior that was seen in the Fcal energy resolution may be explained by the angular resolution term. Colin: It is also the case that the pi0 peaks extracted for high energy may suffer from poor fits to peak and background.
- Notes added by Zisis (Elton had to go to his shift): A discussion took place on whether Cristiano’s analysis should be attempted on inclusive pi0. Matt stated that CF’s method is the best way to measure the width (background manageable) . The old FCAL plots on slide 6 were a decent early attempt, but CF’s method gives more robust results. Christina asked about the opening angle between two photons at 4 GeV and Matt said that it is 2.5 deg; Cristiano added that his cuts that the two photons have angles greater than 2 deg and be apart more than 12 cm eliminates extreme opening angle events.
- FCAL Energy Resolution Study (Cristiano Fanelli)
- NIM articles
- Any other business