Star-tpc-l mailing list

[James H Thomas <jhthomas AT berkeley.edu>]

Present:  ShinIchi Esumi, Gene, Flemming, Yuri, Alexei, Frank, Jim

 

== FST Material Discussion

    -- Material budget due to FST & Cables & stuff is large in the forward region

    -- 3 layers, 1.5% per layer & large angle tracks (+Cables, etc) adds up to ~10% RL

    -- This may affect tracking in any future BES studies (esp. 4.5 GeV)

    -- FST installation and material budget discussed in some detail here:

        https://drupal.star.bnl.gov/STAR/blog/videbaks/FST-geometry-and-material

    -- STAR NIM for FST is also useful and very comprehensive

    -- Yuri showed slides with current Geant3 geometry.  FST and STGC included.

    -- 2025 additions to the model include 3 FST layers but not cables, cable trays, or Novec 

       cooling lines etc.  Model needs improvement.

    -- Yuri plans to run simulated tracks through the current model to see how much the current 

       model affects fixed target tracking and analysis.  With and without material.  If significant

       effects are seen, then we will have to work harder on the model.

    -- No material included for STI tracking, yet

    -- Some FST components can be removed but we would have to remove the pole tip to do it.

    -- We do not want to prematurely remove the FST and/or STGC in case we have a p-A 

        or d-A run

 

== Hardware

    -- Hardware working smoothly

    -- West laser not working well.  May need a new lamp.  Takes 1 hour inside cave to fix it.

    -- Supply of gas is OK.  Another 12 pack arrived so we have about 80 days of methane.

    -- One outer sector HV has been reduced to 1200 volts because it keeps tripping with 

        high luminosity beams

 

== Electronics

    -- Tonko is back from vacation (yippee)

    --  Up to 7 RDOs masked out, recently.

    -- Tonko and Flemming will start to look carefully at the list this afternoon

    -- Flemming has started a Blog for Run 25 RDOs, FEES, etc. to track their status

    -- Ops meeting group decided to limit luminosity to 90 kHz at start of run because 

       auto-recoveries are taking too much time out of the run.

 

== Software

    -- Yuri has finished 3p85 GeV fixed targe dE/dx calibration.  Calibration is now in the DB.

    -- Gene is reviewing whether we are losing an unreasonable number of hits on tracks 

       due to the high luminosity beam. 

    -- High occupancy is affecting tracking. We may have to deconvolute the clusters 

       due to high Luminosity

    -- Need good space charge calibration before this study can go too much further

    -- Work in progress.  Baoshan is helping and making excellent progress.

    -- Fast offline has a quick and dirty space charge calibration in the DB, already.

    -- STAR has started ½ field running due to high temperatures.  These runs will 

       need a custom space charge calibration, too.

    -- Note that ½ field data from 2023 has not been calibrated yet.  Manpower needed.

    -- The magnet cooling tower struggles when the temperature exceeds 90 F, forcing us 

        to go to ½ field running.  How many 90 degree days will we get in July and August

    -- AI result: “Based on available data for nearby areas, Upton, NY likely experiences 

       around 15 days with a high temperature of 90°F or above each summer.”  

    -- More detailed analysis suggests as many as 10 days in July and 10 days in August, 

        with 5 days each month as a lower bound.

Cheers,
Jim

--

Jim Thomas

Email: jhthomas AT berkeley.edu

Phone:  USA  (510) 759-4936

Homepage: https://sites.google.com/berkeley.edu/jhthomas

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