The talk will be posted on BNL indico
https://indico.bnl.gov/event/10740/

This page will be used for draft talks

agenda
- hardware status
- software updates
- calibration review

 minutes:

hardware
- the west laser had a LV power supply with a bad fuse. Alexie got an access fand fixed in < 1 hour
- Alexei monitor gas and will adjust methan concentration slightly.
- new hot channel in sector1. Have asked Tonko to mask out

FF request.
Gene summarized the FF request as it had emerged from the calibration review. It is important to run FF setting to seperate alignment, E*B distortins
but having data from both polarities. Yuri & Gene confirm that the 20M RF is a good sample from RFF and it was concluded we should request a change as soon as practical and on Wednesday access day at latest. Alexei brought up request to at at the time of switch that a high stat laser run ~20k is taken jest before magnet change and another one is taken with FF after the change, and magnet stabilized.

Yuri showed the dedx for his run 20 calibration for collider data and fixed target.There is some room for improvement in particular for the FXT target data.
Yuri showed that the readout of the magnets current fluctuate on a 15 sec time sacle between two distinct values. Current code only has one magnet value per run so it gives rise to distinct bands of say K0_as there is a scale factor between current read and Field suggest to use average value for future.

Gene discussed a Minor problem in sector alignment distortion correction as shown in attached slide on web page.
Looked at run 18 distortion maps and notice a missing featue that he expected namely spikes missing between inner and outer sector. This is due to an un intentional change of code in 2014. Demonstrated with differences that these effect are likely small. One measure of #primary tracks is sub-promille.

aAgenda
- hardware status
- run progress
- software
- TPC Review Planning


Charge to committee

  We just formed the STAR TPC calibration review committee. It is timely and critical to look at the offline calibration tasks and issues. The committee is charged to evaluate the readiness of the TPC calibration for the BES-II data production and provide answers to the following questions by the end of March 2021:

 

1.     What is the status of the tracking and production calibration? 

2.     Where is the bottleneck of the TPC calibration procedure? 

3.     Are there enough collaboration manpower and resources for the tasks? 

4.     How are the online/operation/fast-offline/PWGs efforts coordinated to accomplish the goals? 

5.     Is there a clear document of procedures in calibration and what are the unexpected and expected issues in BES-II datasets? What are the steps in calibration, and how are the current responsibilities assigned?

6.     What is the timeline and path toward completion of whole BES-II calibration for production? 

7.     Any lesson learned toward future runs?

 

The members are:

Zhangbu Xu (Chair)

Bill Christie

Carl Gagliardi

Frank Geurts

Marian Ivanov

Ivan Kisel

Tonko Ljubicic 

Maria Stefaniak

Jim Thomas

Qinghua Xu

Xin Dong (ex officio)

Rongrong Ma (ex officio)


Talks and subject area.
Geometry & alignment (Yuri)
•  Drift velocities
•  dE/dx
•  Specifics for Run 19
•  Cosmic data
•  Beam data
•  Laser data
•  What is the procedure for alignment; How is it documented
•  Bottleneck in timely calibrations
•  Validation procedures and QA
•  Lessons and procedures learned from iTPC prototype commissioning
•  Present/summarize clearly the open/unknown issues and potential concerns (all talks)

Surveys done (Flemming)
• Alexei, Jim and Yuri (operation survey)
• Other detectors as calibration tools (GMT, TOF,  BEMC)
• How they are included in the calibration procedure

Correction Distortions (Gene)
• Dynamic distortions: SpaceCharge & GridLeak
• Static distortions

Resources for Online and express stream (Hongwei)
•  Recap of resources
•  Activities
•  Relation to FastOffline

Calibration (Irakli)
•  T0
•  Long bunch timing, FXT and collider BES-II
•  How is express and fast offline used in calibration
•  Resource/tools/datasets use

QA,QC (BES-II)   (Dan)
•  Recap of resources
•  How are working groups involved in this
•  Feedback, requirements to calibrations

 agenda
-- hardware
-- run preparation
-- software
    + Gene: Residuals with the iTPC

TPC meeting Jan 20, 2021

 

Hardware:

Inspection walk tru done. Checked HV. Leak rate is good < 2l/min after rep of valve.

Prepare for low Ar flow Friday, high flow Sunday. Blue sheet Monday

Laser Need to replace 3 windows- ordered. East side very good West some rafters missing due to windows.

 

Run Prep:

DB for TPC should be initialized. Yuri

Discussed HLT running for cosmics. HLT will be commissioned during cosmics, files should be kept as they are useful.

 

Discussed the proposal for running FF. With the current  schedule for beam injection Friday evening in Blue, and Gas flow starting Tuesday morning at best one can get about ~ 1 day worth maybe 10M. As it will also be the first day of running it will probably be used for commissioning (e.g GMT triggers) the sample can be less. The EPD and BBC installation will also take place Thursday/Friday when magnet has to be off.  Yuri said it could be useful for checking but not enough for full calibration.

 

Gene presented his ongoing study of inner-outer matching looking at very low-luminosity run from 19.6 , and under different conditions. See blog https://drupal.star.bnl.gov/STAR/blog/genevb/residuals-itpc

The 2020 calibration gives large track residual at the lowest pads (1-6 or so), while the ‘old’ does not show this but slightly larger values. Irakli pull up some plot and see similar effects in some of his results (from maybe a year ago).

 

Yuri is working on alignment. No results yet.

 

 

 

 agenda
-- hardware
-- software


Minutes

TPC weekly meeting

 

Hardware;  Alexei excused. Is working on laser and gas system

 

The GG driver modules have been installed (Christian, as Tim is out) One module does not provide HV. There are two spare modules.

David is communicating with Tonko how best to provide the SC for the Gating Grid.

 

Software

Irakli had at LBNL meeting; provided an update to me after meeting

 

“I talked to Yuri last week about progress and the calculation of the distortions.

 

I also pointed out to him a little problem in the reading of the inner sector position parameters from the database. We reached out to Dimitry and he changed the readout for that table. It hopefully was not affecting anything, but now I have a good way to compare apples to apples as far as the inner sector position parameters are concerned.

 

While doing so I noticed that that is where a huge shift in z direction originates, so now I want to see if that is the right result or an artifact from what I've been saying – one can end up in a local minima for the alignment procedure. I will keep you guys updated I the days to come. I am running these jobs as fast as possible (Dmitry's fix has been applied only Monday).”

 

Yuri presented some intermedial results on his investigations of showing effect of his modified equations as discussed in the previous meeting 12/9/2020 that also have the documents

https://www.star.bnl.gov/~fisyak/star/Tpc/Distortions/

 

Unless there are updates we need to discuss in person this was the last TPC meeting for 2020. Please send updates to the mailing list until then 1/5/2021

zoom info

 

Minutes:
Tim reported on Gating Grid status
Crate has all modified modules. It was tested locally.
The web based script by Tonko does not seem to work after the upgrades. He is aware of it.
The polarity is swtiched at the connector for all. 
The sector 8 is special and should be checked.

FV will contact David on the slow control of the gating grid; how should it be implemented?

Alexei has been working on laser system
- optics replaced; signal looks good
- started with alignment of akll rafters
- propbably will need another week

Software
- no discussion as some key people could not join the meeting today. There was a longer discussion on the run-19 alignment at the monthly S&C meeting
- It is of high priority to get this resolved; will have as agenda point next week