Star-tpc-l mailing list

[videbaek <videbaek AT bnl.gov>]

TPC meeting June 29, 2023
Present: Gene, Jim, Yuri, Tommy, Alexei, Flemming

Hardware-
Summer is here. TPC handle pressure variation during storms well.
Laser ok. Vdrift dropping to 5.42. There is gas in the current six-pack 
for another 5 days.
Alexei on staycation,  and will follow gas situation closely.

The quote for new HV for Cathode HV supply was finally pinned. BNL 
wanted US firm, but we ended up having Wiener approved for this 
purchase. 28 wks delivery
Discussion on connectors for wiener different from Glassman, and how to 
implement. Alexei will consider and discuss with Tim C. how to do this 
(for next run)

Question on Gating grid performance. No issues with device. Gene will 
still like take several runs
with same beam condition and rates from 1 to 5Hz. Will come with request 
again, as it was not well received at 10 o’clock meeting.
Suggestion in retrospect: send the request to ops list, and outline 
plan; indicate it was discussed already at trigger board.


Electronics
DAQ5K is now operational, with all of TPX and iTPC firmware updated. 
Some TPX RDO’s have issues at high rate. Likely related to electronics 
components. Some FEEs have been masked out.
Some tuning still to be done for iTPC part. MB-zdc triggered data runs 
at ~4.2 kHz, and optimal at 13 KHz input trigger rate and ~50% dead.

Software

Yuri discuss work by him and Tommy regarding the RRF vs FF data.
See 
https://drupal.star.bnl.gov/STAR/system/files/OO200GeV2021RFvsFF_2023ReV_1.pdf
For details. Main point is that only run 21 OO FF data shows issues. 
Implement a non-understood fix of having additional 1 mrad rotation for 
run 21 FF running.
Not in agreement with measurements taken before this years run. Will 
have to be revisited by measurements at end of run23 (September) FF 
filed cosmics and measurements,

Yuri also show results from de/dx calibrations of the 7.7 and 19.6 GeV 
data. Overall looks good, but small differences looking at decays of phi 
and lambda’s
See https://drupal.star.bnl.gov/STAR/system/files/RunXIX_XXFXT.pdf
 For details.

Yuri also pointed out that the new clusterfinders and pad respeonce has 
to be investigated. Important for embedding.

Some progress on space charge (Gene)
 Three prongs
1.      Looking a dA data , symmetrc (background) vs asymmetric (dA coll)
2.      Pp500 Temple work; identifying runs, trining new person
3.      Initial run23 SC particular for HLT online.


Have a good July 4th.



--
Flemming Videbaek
senior scientist, emeritus
videbaek @ bnl.gov
Brookhaven National Lab
Physics Department
Bldg 510D
Upton, NY 11973

phone: 631-344-4106
cell     :  631-681-1596