Star-tpc-l mailing list

[videbaek <videbaek AT bnl.gov>]

TPC meeting June 20, 2024 (solstice)
Present Frank, Jim, Yuri, Alexei, Gene, Matheu, Flemming, Tommy

Hardware:
Progress with the NMR probes. Could not readout through the RS232 port. 
Turns out the $88 paort (GPiB) works, Tim purchases readout board. 
Further discussion will take place with Alexei, Tim and David how to 
incorporate this into slow control readout and data storage. Will need 
interface to IP readout so it can be stored. Discussion on absolute vs. 
relative readout. Certainly, it is very useful to understand time 
stability; much better the current readout. The value should be 
calibrated vs. analysis e.g of K0s mass. We already learned since 
installation that the current readout in not a proper reference, 
stability not good.
The nominal value readout is 0,4988(6) ie. A 1.2 gauss deviation for the 
nominal 5kGaus field.
After meeting Alexei supplied informationon position:
“There are two probes sitting on East side of TPC, Z position is about 
1300mm from magnet center. So Z is -1300mm,  and X is about -60mm, Y is 
about. +/-70 mm.
After this run I'll order survey service to have more accuracy. Now my 
estimation is about 20-30mm.”

Laser operations by crew is not always good. Alexei will (again) 
instruct crew as one has to refocus during the datataking as it drifts.

Electronics:
Tonko fixed 4 RDO today, had to mask one FEE out. Due to power issues 
for RDO

Software:
Gene
1)  Space charge calibrations for run 22 pp proceeding well. On pass 2. 
Had to redo about 10% a the had failed (overwrite of files). Looks 
pretty good and will proceed (soon) to pass 3.
2)Joe Nam (Temple) who earlier had done space charge, looked on some 
data from pp 22 to look at h+/h- for a few fills. Does see fill to fill 
effect. Lokks like a good tool to confirm new calibrations.

3) Gene have discussed with (QCD) pwg full production time for run 22. 
With default setup it looks like >= 1year, so no time for additional 
repeats.
Look to see for ways of improved time. Showed that skipping ~ ½ itpc 
rows in a couple of different configurations could improved reco time by 
~ 50%. Have not demonstrated (task of pwg) if this affect the physics. 
Cold QCD sees this favorable, but other pwg not yet asked.

4) Gene had e-mail from dAu flow analysis group that had observation of 
loss of hits near central membrane. Different of observation from FXT 
group. Wa mentioned tha flow group always have taking such in eff into 
account (Jim). There was possible difference between STI and STICA.

5) observation by Zach (?) UCD  that there is a low pt de/dx difference 
expected and observed. Was requested through Matheau to get 
documentation- possible presentation next week by Yuri, so he knows what 
to look for.


Software II
Yuri had nothing new to report. Reviewing alignment found and presented 
last week.

Frank presented the current exceptions that the proton-cumulants is of 
high importance in view of the recent very successful presentation of 
the collider data at CPOD and upcoming publications. DOE & BNL 
management have requested that a timeline has to be presented this FY 
that contains milestones, that will be followed, that can lead to 
presentation of final results by QM25, and subsequent publication. Based 
on PWG discussions and timelines for analysis, discussion, and approval 
it seem that production of the FXT energies (3.2, 3.5, 3.9, and 4.5) has 
to be done by end of September. Thus having the newly obtained alignment 
that resolved the track-breaking observed by UC Davis group incorporated 
into standard software as a first step, and confirmation of quality  
sufficient for next calibration steps should be given high priority.
Frank asked Yuri to prepare for a presentation at next weeks mgt meeting 
for a status and baseline.
Frank reaffirmed that mgt would help with expediting the approval to 
incorporate into GitHub, strongly recommending to split it into several 
smaller, better manageable requests.



--
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