Difference between revisions of "May 4, 2017 Calorimeter"
From GlueXWiki
(→Tentative Agenda) |
(→Minutes) |
||
Line 48: | Line 48: | ||
# [[GlueX-Collaboration-May-2017|Collaboration Meeting]] May 15-17, 2017 | # [[GlueX-Collaboration-May-2017|Collaboration Meeting]] May 15-17, 2017 | ||
# Action Items | # Action Items | ||
+ | #* Matt: Add maintenance of FCAL bases to action item | ||
# Activities during the down | # Activities during the down | ||
− | # FCAL update | + | #* Elton: We have had discussions with Chris Stanislav regarding repair of some BCAL channels. |
− | # BCAL update | + | #* Zisis: Tegan will arrive on May 17 and Zisis on May 23 and would like to take more LED data, especially turning off selected HV for better understanding of individual channels. |
+ | # FCAL update (Ahmed) | ||
+ | ## 4 ns shifts | ||
+ | ##* Offsets have been determined relative to a reference run. At first he found 0, +/- 4 ns offsets. Speaking to Mark, we only expect 0 and 4 ns offsets. Adjustment of the reference run allows al offsets to be set to 0, 4 ns. This is being implemented. | ||
+ | ##* A second pass will determine offsets of one channel relative the others by referencing these to the RF signal. | ||
+ | ##* These time offsets are expected to be completed in about 2 weeks, likely not before the production launch. | ||
+ | ##* Mark: Will need a new table in CCDB to hold the offsets | ||
+ | ##* Mark: What is the timing used for? Matt: hit selection based on timing, e.g. eliminating EM showers that are out of time. Sean: Timing selection are being made to the RF bucket. Matt: Uncomfortable making such tight timing cuts on the FCAL at this stage of calibration. | ||
+ | ## Low intensity runs / normalization | ||
+ | ##* Finds that for the low intensity runs, the pi0 mass peak shifts down by 4-5 MeV. This is not understood, but is confirmed by LED data, which shows a 5% drop in intensity. There also appears a non-trial geometry dependence to this systematic. During that period the pedestals and HV remain constant. | ||
+ | ## time walk corrections | ||
+ | ##* The time-walk corrections to correct for slewing in the FCAL timing has been implemented in Adesh's local branch. Source of slewing is unclear but corrected away. | ||
+ | # BCAL update (Mark) | ||
+ | ## 4 ns offsets | ||
+ | ##* Offsets for 4 ns have been completed and entered into the CCDB run-by-run | ||
+ | ## Other higher level calibrations (attenuation length, gain ratio, position offsets, time difference offsets and time sum offsets) completed | ||
+ | ##* These calibrations have been extracted once and seem to be valid over the entire run | ||
+ | ##* Sean initially saw some discrepancies in PID variables, but they seem to be related to his software installation | ||
+ | ##* All of Mark's calibrations are being used in the current monitoring launches. | ||
+ | ## LED timing (Elton) | ||
+ | ##* Timing offsets using the time difference between (down-up) were derived for runs available on /cache. They show good agreement with Mark's constants except for one run. | ||
+ | ##* All 4ns offsets have been applied to the downstream end, as implied by comparisons to TDCs as well as raw times compared to the trigger. | ||
# Calibrations | # Calibrations | ||
# Reconstruction and Simulation | # Reconstruction and Simulation | ||
# NIM articles | # NIM articles | ||
# Any other business | # Any other business |
Revision as of 12:21, 4 May 2017
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
- Disable red LED string in dark room to avoid leaving it on in the future. (Adesh)
References
- FCAL HDFCAL log book
- BCAL HDBCAL log book
Tentative Agenda
- Announcements
- Collaboration Meeting May 15-17, 2017
- Action Items
- Activities during the down
- FCAL update
- BCAL update
- Calibrations
- Reconstruction and Simulation
- NIM articles
- Any other business
Minutes
Attendees: Elton, Adesh, Mark (JLab); Will (CMU); Sean (NW); Christina (Athens); Matt (IU); Zisis (Regina)
- Announcements
- Collaboration Meeting May 15-17, 2017
- Action Items
- Matt: Add maintenance of FCAL bases to action item
- Activities during the down
- Elton: We have had discussions with Chris Stanislav regarding repair of some BCAL channels.
- Zisis: Tegan will arrive on May 17 and Zisis on May 23 and would like to take more LED data, especially turning off selected HV for better understanding of individual channels.
- FCAL update (Ahmed)
- 4 ns shifts
- Offsets have been determined relative to a reference run. At first he found 0, +/- 4 ns offsets. Speaking to Mark, we only expect 0 and 4 ns offsets. Adjustment of the reference run allows al offsets to be set to 0, 4 ns. This is being implemented.
- A second pass will determine offsets of one channel relative the others by referencing these to the RF signal.
- These time offsets are expected to be completed in about 2 weeks, likely not before the production launch.
- Mark: Will need a new table in CCDB to hold the offsets
- Mark: What is the timing used for? Matt: hit selection based on timing, e.g. eliminating EM showers that are out of time. Sean: Timing selection are being made to the RF bucket. Matt: Uncomfortable making such tight timing cuts on the FCAL at this stage of calibration.
- Low intensity runs / normalization
- Finds that for the low intensity runs, the pi0 mass peak shifts down by 4-5 MeV. This is not understood, but is confirmed by LED data, which shows a 5% drop in intensity. There also appears a non-trial geometry dependence to this systematic. During that period the pedestals and HV remain constant.
- time walk corrections
- The time-walk corrections to correct for slewing in the FCAL timing has been implemented in Adesh's local branch. Source of slewing is unclear but corrected away.
- 4 ns shifts
- BCAL update (Mark)
- 4 ns offsets
- Offsets for 4 ns have been completed and entered into the CCDB run-by-run
- Other higher level calibrations (attenuation length, gain ratio, position offsets, time difference offsets and time sum offsets) completed
- These calibrations have been extracted once and seem to be valid over the entire run
- Sean initially saw some discrepancies in PID variables, but they seem to be related to his software installation
- All of Mark's calibrations are being used in the current monitoring launches.
- LED timing (Elton)
- Timing offsets using the time difference between (down-up) were derived for runs available on /cache. They show good agreement with Mark's constants except for one run.
- All 4ns offsets have been applied to the downstream end, as implied by comparisons to TDCs as well as raw times compared to the trigger.
- 4 ns offsets
- Calibrations
- Reconstruction and Simulation
- NIM articles
- Any other business