Star-tpc-l mailing list

[Richard Witt <witt AT usna.edu>]

Present: Alexei, Jim, Flemming, Tommy, Prashanth, Yuri, Gene, Irakli, and myself

== Hardware

— ready to measure magnetic field

— cause of drop in drift velocity is still not certain

— new gas remains primary suspicion

— expecting some leak in methane

— Alexei is watching

— access yesterday

— restored driver for laser, both now operational 

== Electronics

— no significant update this week

— things are going well

— watching for persistent effects in QA

— Yuri asks for a final date when TPC is completely upgraded

— no solid date, but group expectation is a couple weeks

== Software

— dE/dx calibration production for 19.6 and 14.5 was done 

— will also requested

— 200 GeV d+Au space charge calibration is being examined

— was symmetric which was puzzling

— perhaps a large part of SC is not coming from collisions

— meeting with Temple group later this week 

— discuss Run 22 500 GeV p+p SC calibration

— Yuri reported on check of dE/dx calibration for SL23c 19.6 and 14.5 AuAu

— resolutions are same so issue considered closed

— Yuri also reported on look at Run23 

— anomalous drift velocity drop began after methane bottle was changed 

— extended from May 24th to May 31st

— DV began to recover after bottle was changed again on May 30th

— no severe effect observed on dE/dx (effect is ~10%)

— some offset observed in z direction (need start time adjustment)

— some offset (~.6 cm) observed between east and west with opposite sign charges

— expectation is it’s due to space charge

— K0short is slightly heavier than expected 

— Yuri has posted slides shown above to the list

— Irakli reported on supersector alignment

— anomalous shift in local y (radial) as iterations appear to be converging in x and z

— small group of closely clustered sectors

— Irakli will post a link to the list with current results

== AOB

— nothing new 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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