TPC
General Information
This page serves as a centralized page for TPC group's meetings (starting May 1, 2019).
TPC Group Hypernews [Used before October 2019]
https://www.star.bnl.gov/HyperNews-star/protected/get/startpc.html
TPC Group Mailing List
star-tpc-l@lists.bnl.gov
TPC Group Meetings
2020
2019
- 2019-12-18
- 2019-12-11
- 2019-12-04
- 2019-11-27
- 2019-11-20
- 2019-11-13
- 2019-11-06
- 2019-10-30
- 2019-10-23
- 2019-10-09
- 2019-10-02
- 2019-09-25
- 2019-09-18
- 2019-09-11
- 2019-09-04
- 2019-08-28
- 2019-08-14
- 2019-08-07
- 2019-07-31
- 2019-07-24
- 2019-07-17
- 2019-07-10
- 2019-07-03
- 2019-06-26
- 2019-06-19
- 2019-06-12
- 2019-05-29
- 2019-05-22
- 2019-05-15
- 2019-05-08
- 2019-05-01
TPC meetings are held on Wednsesdays at 15:00 Eastern Time. Meeting room 1-189 in physics building 510 @ BNL.
The Bluejean connection
Title: STAR TPC Weekly
Description: Weekly TPC meeting for the STAR Collaboration
Community: STAR
Phone Dial-in
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Meeting ID: 628 045 566
Direct link: https://bnl.bluejeans.com/628045566
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
agenda
- hardware status
- operation
failures, humidity, magnet current measurement by C-AD
additional FF cosmic?
- software
- calibration status
- plans for shutdown (reminder)
Topic: TPC weekly
Time: Jun 23, 2021 03:00 PM Eastern Time (US and Canada)
Every week on Wed, until Aug 4, 2021, 7 occurrence(s)
Jun 30, 2021 03:00 PM
Jul 7, 2021 03:00 PM
Jul 14, 2021 03:00 PM
Jul 21, 2021 03:00 PM
Jul 28, 2021 03:00 PM
Aug 4, 2021 03:00 PM
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Weekly: https://bnl.zoomgov.com/meeting/vJItdOmurDksH_3czqVgkBAd421P_ZMYLYo/ics?icsToken=98tyKuiurjgqHNaXthzBeI89EqPga-nFiWJmlfBehg7TBCtxQweiZLNyDYhSKfTp
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TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
agenda
- hardware status
- operation
failures, humidity, magnet current measure
- software
- calibration status
- plans for shutdown (reminder)
Topic: TPC weekly
Time: Jun 23, 2021 03:00 PM Eastern Time (US and Canada)
Every week on Wed, until Aug 4, 2021, 7 occurrence(s)
Jun 23, 2021 03:00 PM
Jun 30, 2021 03:00 PM
Jul 7, 2021 03:00 PM
Jul 14, 2021 03:00 PM
Jul 21, 2021 03:00 PM
Jul 28, 2021 03:00 PM
Aug 4, 2021 03:00 PM
Please download and import the following iCalendar (.ics) files to your calendar system.
Weekly: https://bnl.zoomgov.com/meeting/vJItdOmurDksH_3czqVgkBAd421P_ZMYLYo/ics?icsToken=98tyKuiurjgqHNaXthzBeI89EqPga-nFiWJmlfBehg7TBCtxQweiZLNyDYhSKfTp
Join ZoomGov Meeting
https://bnl.zoomgov.com/j/1603062265?pwd=Tm9Nb3lpcWt0L1ZUcUg0TjV0T2Vydz09
Meeting ID: 160 306 2265
Passcode: 880354
One tap mobile
+16692545252,,1603062265#,,,,*880354# US (San Jose)
+16468287666,,1603062265#,,,,*880354# US (New York)
Dial by your location
+1 669 254 5252 US (San Jose)
+1 646 828 7666 US (New York)
+1 669 216 1590 US (San Jose)
+1 551 285 1373 US
Meeting ID: 160 306 2265
Passcode: 880354
Find your local number: https://bnl.zoomgov.com/u/aM2ZS218b
Join by SIP
1603062265@sip.zoomgov.com
Join by H.323
161.199.138.10 (US West)
161.199.136.10 (US East)
Meeting ID: 160 306 2265
Passcode: 880354
| Time | Talk | Presenter |
|---|---|---|
| 15:00 | dE/dx from express production 3p85GeV_fixedTarget 2021 ( 00:05 ) 0 files | Yuri Fisyak |
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
Present:
Prashanth, Gene, Alexei, Babu, Dan, Ben,Yuri, Hongwei,Flemming
Hardware:
Two major issues.
- West laser is unstable, and difficult to tune. Probably not mirror issues.
- Sector 15 HV section 3 (itpc) tripped yesterday afternoon (June 15) and cannot hold voltage. Turned to 0 overnight. Today it held 1035 for 10 min but then tripped. AL left it at 500 V.
- Alexei will investigate further on Monday’s access day.
• Since last week 21-4 is now masked out. Tonko report in his records
• iS21-4 dead [11 Jun]
o comes up but then looks like it loses power and dies again
o perhaps a FEE is shorting out?
o Masked
S24-4 masked out for reminder of run.
Included the bad HV section about 6-7% of iTPC is out
Run-20 calibration (Babu). Has problem with failed jobs. Not enough jobs has completed to finish period 1 dynamic. Will discuss failures with Gene.
Yuri reported no progress on FF calibrations and understanding.
Reports that dE/dx for the FXt is down ~8% compared to 7.7 GeV where it was first calibrated, and additional drift down by about 4% here in June.
Gene reports that for run 22 there are ideas to increase rates, reduce data volume by masking out ~10 innermost row of iTPC. These are ‘black in pp 500 anyhow. Gene will run some simple simulations (Jim Thomas macro’s) to see what effect in tracking will be w/o these. Full simulation may also be needed. There will be a talk at the analysis meeting on this by Tonko.
Hongwei confirmed that the discrepancy between HLT good and offline is about 3-4% after dealing properly with vertex selection in his offline runs.
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- operation
- calibration status
- FF field
Yuri posted additional slide on FF DCA_y
https://drupal.star.bnl.gov/STAR/system/files/OO200GeV2021RFvsFF_0.pdf
Tpc meeting June 9, 2021
Present: Gene, Yuri, Dan, Babu, Alexei, HongWei, Flemming
Hardware:
Humidity has been creeping up a bit. Yesterday some high current in fieldcage due to humidity.
Quote from Gene
“I find that the blower A/C being off on June 5th did raise the inner field cage currents during two physics runs:
22156024 and 026
I propose simply to mark these two runs as bad. I would advise in situations like this to stop the fill and address the blower ASAP rather than waiting for RHIC operators to reach their own end-of-fill.
The number of auto-recovery has gone up during the 3.985 GeV FXT . Beam is likely dirtier. Date for 24:s4 looks fine
Operation:
The ops crew noted alarm for magnet current at ops meeting. It seems to be correlated to the lower mean current observed the last day. This was observed earlier in the run by Yuri see https://drupal.star.bnl.gov/STAR/blog/fisyak/averaged-star-magnet-current-table. The large oscillation is due to measurements (+-2A)– this is understood. The drop today as well as drops earlier in the run is not. The oscillation gives a K0S mass change of ~0.4 GeV/c**2.
Yuri was asked to look at mean of K0S mass for the periods (or a period) where the mean is down to -4112 for average to identify if it is due to measurement or to change in magnetic field.
Alexei has earlier noted that for next year we should have a NMR installed with high precision field measurement.
Calibration:
At this point the TPC calibration are done for run-19.
Babu plans to have an update next week for the run-20 iterations.
Yuri had an additional plot of the FF local DCA_y ivs. Sector number
https://drupal.star.bnl.gov/STAR/system/files/OO200GeV2021RFvsFF_0.pdf
The fits correspond to a rotation around the vertical axis of the field relative to TPC, and is of similar magnitude as the measured difference between field and TPC at zero-filed and incorporated in the ‘twist distortion correction. Yuri has discussed with Alexei and Bill C, to see if this can be understood i.e why changing the field to result in such change.
iTPC sector 24
Unfortunately managed to delete conent when trying to insert table of runs with this issue.
Will restore later. (5/28)
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- hardware update
- operations
- calibration updates
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC meeting April21 minutes
Present:
Alexei,Babu, Flemming,Gene,Hongwei,Yuri
TPC running well. The pizo driver for the laser failed , no power,was adjusted during quick ccess, and then rebooted today during access. Lost about one laser run during. Will investigate how remote reboot can be done. Such failure has happened 1-2 per run.
Flemming present a few more observation on the single bad pad hot due to values this seem to have pedestal subtracted incorrectly. This is intermittent and usually, but not always clears on next run. Also it only 5-10% of events with this failure. See https://drupal.star.bnl.gov/STAR/blog/videbaks/tpc-qa-2021
for more details
The 19.6 GeV calibration sample is complete. Includes dynamic space charge, and event by event t0 correction. EPD had time offsets calibrated/changed at some point in time during the 19.6 GeV data sets. This change is now in DB. The 14.5 GeV should be done by the weekend. Babu will start looking at the run 20 soon.
The sample(s) can now be checked for BTOF calibrations, and dE/dx.
If the mass square difference seen in east persists with the DbTpcMaker that was updated, there will be additional work to identify this issue. The TOF group will not sign off with a mass split of approx. 1%.
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- hardware status
- operations
- calibration status
| Time | Talk | Presenter |
|---|---|---|
| 15:00 | Averaged STAR magnet current table ( 00:10 ) 0 files | |
| 15:00 | Averaged STAR magnet current table ( 00:10 ) 0 files | |
| 15:10 | 2nd round with Run XIX calibration production for 19GeV and 14p5GeV samples ( 00:20 ) 0 files | Yuri Fisyak |
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC minutes April 5, 2021
Present: Alexei, Hongwei, Gene, Turi and Flemming
Hardware:
- TPC running well.
- Used access to put pizo driver on remote PS
- Adjusted methane content.
Operation:
Sector 20 RDO 3 had to be masked out. Unfortunately, the crew did not reboot iTPC on run control, so there are ‘fake’ cluster in the data. The manual for masking out has been updated to remind people to get this done.
There is currently no code to perform masking in the offline code. i.e. skipping hits in masked sectors.
Calibrations:
Gene summarized impressions from S&C calibration discussion. There are small deviations in M**2 plot with newest calibration. The deviation seen corresponds to order 0.2% in momentum. Indicates imperfect calibrations in TPC and/or BTOF. What are requirements to physics analysis to be performed? PWG should define?
It is important to have clarifications if current alignment and calibrations is sufficient to do physics for at least some physics analysis, since redoing / improving alignment will take several months
Yuri iterated the deviation is ~40% (at what momentum?) of mass**2 width. Have requested plots from BTOF group to get additional finer divided information. Is not convinced its TPC; Needs additional info to separate. Example: plotting tray numbers rather than phi.
Babu has done first pass on run-20 9.2 GeV dynamic distortions. Run 19 is done.
Yuri is revisiting dE/dx for both 19 and 14.5 GeV. Not satisfied with aging effect treatment.
If I recall, there was an early fast drop after installation of iTPC reported by Yuri long time ago.
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC meeting May 12, 2021
Present: Alexei, Gene, Yuri, Hongwei and Flemming
Hardware:
Basically in good shape. Struggled with HV GUI’s likely due to ITD scanning during the access day. Sector 20 outer was repaired by Tonko and Mike, bad RORC card.
Has observed the part short of west filed cage.
Alexei has the calibrated NMR in house.
Operations:
The O+O running very clean. The 1.5mrad crossing angle and levelling at ~3-4kHz Mbias results in very little if any dynamic space charge.
This bodes well for the FF setting to be run in about a week.
For the central collisions to be run right after the RFF 400 M Mbias the Mbias rate will be possibly ~20kHz.
Calibrations:
Gene looked at h+/hi ratios vs. pt for the 19.6 Gev au+au and reports seeing sector to sector variations;
https://drupal.star.bnl.gov/STAR/blog/genevb/h-h-run-19-196-gev
These variations are at similar level as after run 12 alignment calibrations i.e little overall effect but sector to sector variations.
The sectors showing largest effect correlates with Zaochen's findings in mass2 splitting in BTOF
Thus the variation is most likely due to TPC calibrations.
Yuri commented that until we have the FF data its unlikely that underlying reason, and improved calibration can be made. It is also likely to be a large effort, not a few weeks.
Yuri reported that dE/dx calibration for 14.5 and 19.6 is completed
It was also reported to S&C management
https://drupal.star.bnl.gov/STAR/system/files/19%20and%2014p5%20GeV%20dEdx%20Calibration.pdf
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- hardware status
Gene: humidity impacts seen on inner field cage currents. See image shown further down, below agenda. More on this topic in general in my blog.
- operations
- calibration status
| Time | Talk | Presenter |
|---|---|---|
| 14:00 | OO 200 GeV 2021 RF vs FF ( 00:20 ) 1 file |
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- hardware status
- operations
- software
- big events
- update on test productions
Minutes:
hardware: There was a failure of LV for TPX. broken fan; replaced with spare available in IR.
Have ordered 3 more fans, special. 3 mo. delivery
After a massive trip, one HV section 20-4 itpc seem not to have been brought up and not noticed. Asked David
to check the readouts during this event.
We see very large events in run 19 reconstruction, and in current data taking
a) current activity is related to the beat-squeeze; discussed also at ops meeting. Under discussion what to happen
b) run-19 reco is related to some store with BMM running throughout some runs.
Discussion on TPC calibration. Good progress is being made. Additional discussions later this day.
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
-hardware
-operation
- test production progress
- AOB
| Time | Talk | Presenter |
|---|---|---|
| 14:00 | new schema for Inner Sector alignment ( 00:20 ) 1 file | Hongwei Ke |
TPC weekly
virtual , at 19:00 (GMT), duration : 00:00
- hardware status
- operations
- software
- cluster quantization
-update on test productions
TPC weekly
virtual , at 20:00 (GMT), duration : 00:00
No issue with TPC hardware
-Have adjusted methan content to make Vdrift more constatnt; there were several period in Feb with variations.
- powerdips and magnet trips during last weeks running.
The two runs in day 38 and 66 had outer sector 19 exhibit large excess of charge that extended for all pad and rows for about 150 timebins. See blog entries in https://drupal.star.bnl.gov/STAR/blog/videbaks/tpc-qa-2021 near top of page
Most likely a faulty GG driver board . Alexei suggested looking at signals from board during next maintanence day (unless it get really bad). Will talk to Tim on this.
Gene reported looking at laser un running 7.7 GeV for local clock vs. coll clock. Did not see any different between laser positions. Now looking at prompt hits for two conditions, (UPDATE: small shifts seen for the entire TPC by 14.1 ns, but not on the scale of 1 time bucket; documentation is here)
Yuri show plots
these are references for plots which we discussed today
1. Comparison RF and FF https://drupal.star.bnl.gov/STAR/system/files/TpcCSTransformations_0.pdf
-- the FF has only 34k events.Alignment same for two settings.
2. QA plots for RunXXI (express production) : https://www.star.bnl.gov/~fisyak/star/BES/
---
3. Lasers for different fields
-- no clear pattern. Sector 20 seems consistent for all fields. 20 has best lasers
4. Prompts for different VPD timing cuts
-- shows dependence on collisions timing (sum of VPD timing)
The last plots on meeting page only