Star-tpc-l mailing list

[Richard Witt <witt AT usna.edu>]

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

== Hardware

— Last weekend ran cosmics

— TPC circulation was stopped Monday

— Argon was run for two days and yesterday switched to “summer flow”

— West laser was inspected and has started working again

— replaced a couple of blown fuses

— laser stopped again, but has since returned

— Alexei will start investigating with spare trigger boards

— No official information on start of next Run (24)

— will be at least 18 weeks away

— next run should be 20+6 weeks total

— Discussion about repair of TPC 

— expect a timeframe of September to October

== Electronics

— Report on cosmics recorded was sent to the list (copied below)

—The cosmic FF runs were very successful. Some runs were lost due to west trim coil trips 

— once unnoticed for several hours, and one during night with slower response for help.

— In all we took good data for 34 hours since Friday with

—16.88 M cosmic1-cosmic3 triggers and 50.7 M cosmic wide triggers 

— includes of the the first sets of triggers. 

— This is about 75% more events that Yuri requested for this data sets.

== Software

— FXT 2021 3.85 GeV had higher beam intensity than any other energies

— requires attention on SC 

— Yuhang did simulation with Gene of what SC should be 

— results were used and included in dB

— T0 fields are empty in the dB for this dataset

— Gene uses prompt hits in his method to determine e-by-e T0

— does not correct for the mean T0

— Yuri says there is a T0 offset (jitter) of about 14 ns (1/2 time bucket)

— only seen in 2019 3 GeV data

— but need to check other energies

— need to confirm that trigger decision time has not changed

— Yuri needs ~10k — 100k events and disk space for studies of T0 and vertex resolution issues

— please remove any data from TPC spaces that you no longer need

— Daniel says a preview production of FXT 3.85 GeV would be interesting and useful

— Yuri supports a preview production as well and a dE/dx calibration production

— important to have all primary vertices there and all tracks from pileup vertices as well

— Gene mentioned that the T0 calibration usually done may not be useful for zero bias data

— d+Au SC calibration

— calibration was done for dE/dx and ToF

— day 180-188 is the window

— days 180-182 had collider trying to introduce beam crossing, but introduced high background

— distortions were symmetric between east and west (but should not have been)

— more calibrations work to be done for days 180-182 (see mass^2 splitting in BToF for example)

— days 180-182 account for about 20% of the set, may want to skip that part at least for now

— Yuri on 17.3 Au+Au and 2021 d+Au 

— made first pass over data

— dAu has slightly worse dE/dx resolution 

— would like a few more days to update values currently in dB

— Gene mentioned 17.3 GeV is higher priority if need to choose 

== AOB

— No new items for 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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