Star-tpc-l mailing list

[Richard Witt <witt AT usna.edu>]

Present: Alexei, Jim, Flemming, Yuri, Gene, and myself

== Hardware

— some laser problems

— east laser failed upon attempted start

— replaced lamps and now is working

— last set of spare lamps has been used

— east and west are now very good 

— east laser now needs to be tuned each day

— trigger all okay for now but need to check cables if problems arise again

— if not drastic loss of TPC gas, should have enough methane to last until mid-July

== Electronics

— Unusual feature after magnet trip 

— large noise on sectors 3 and 4 (inner only)

— by Tuesday the unusual peak was gone but still noisy

— by Wednesday it was all gone

— seemed to be positively affected by pedestal runs

— not well understood yet

— looking for diagram of connections with gating grid (one possible interaction)

— HV on sector 11 (most outer) is running at 1100 V rather than 1300

— shows-up as reduced number of tracks in last 8 rows

== Software

— need to get beam-beam data sets calibrated 

— Work on SC

— 3.8 FXT high lumi was done by Gene

— low lumi was low enough that no SC correction was needed

— other data sets that don’t need SC calibration are ready for dE/dx and so forth

— Yuri 

— see: https://drupal.star.bnl.gov/STAR/event/2025/03/27/TPC-group-meeting

— dE/dx pp500 Run22 is considered finished

— some pt resolution difference (1% at 1 GeV) noticed in new alignment vs. old alignment (pp500)

— GMT cosmics (old alignment vs new alignment); several mm differences noted

— new TFG25c released for Alma Linux

— also working on iTPC RDO geometry  

== AOB

— Nothing new reported this week

Best Regards,

  Richard

Sent from my iPad

-- 
"Education is the most powerful weapon which you can use to change
the world."

--Nelson Mandela

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 Richard Witt, Professor of Physics     Phone (USNA): 410-293-6675
    United States Naval Academy         Email: witt AT usna.edu
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