Commissioning and running of sPHENIX

["Yip, Kin" <kinyip AT bnl.gov>]

Hello,

 

When I drove back home, I remember that I had observed similar events a couple/few months ago.  I looked for my own mail in the mailing list and found that it’s my email on Nov. 21, 2023.

 

Last Wed. (Jan. 31, 2024), the TPC group was able to operate all the (72) GEM’s of TPC at the operating voltage (~4400 V) for 4 hours before they went home (for dinner).   After that, we have

been doing a lot of works for cooling --- purging air from the water pipes, fixing leaks, connecting/fixing temperature probes etc.   At the same time, the TPC group has also turned on the TPC again

without and with the FEE’s (front-end electronic cards) and observed the temperature variation with a few temperature settings on the chillers (that we didn’t use during the 2023 run).  They have

also tested the FEE’s and fixed the problems when they found any.

 

This evening, I spent a few hours observing what the TPC groups tried to take cosmic rays with the HCAL trigger.   In addition to local DAQ experts, we have called upon the experts in Colorado for help.

The rack of 2E2 (in the 1008-IR) was not working and we had to power-cycled it.

 

Finally, we were able to use the (not-yet-optimal) online-monitoring program to see tracks.  I attached probably the earliest one tonight that I took with my phone.  There were some noises that you

can see on the plot and the auto-accumulative online monitoring plots also made observing individual events difficult.  We have had to go to very low trigger rate to avoid the plot full of and saturated

hits/tracks.  

 

Nevertheless, we have reached another milestone after 78 days (from Nov. 21, 2023).  Tomorrow, we’ll need to fix the FEE’s before we’ll install line lasers in the South side of TPC.  Because the installation

of line lasers will prevent easy access to the FEE’s.     I have seen some young INTT folks in 1008 and they’re also waiting to install their ROC’s sometime next week.

 

Kin

 

 

From: Yip, Kin
Sent: Tuesday, November 21, 2023 7:44 PM
To: sphenix-l AT lists.bnl.gov; sphenix-run-l AT lists.bnl.gov
Subject: "White smoke" (TPC test succeeded) → prep. for the South starts tomorrow

 

Hello,

 

Thia evening, I can cheerfully report that the long-awaited "white smoke" has materialized (after preparing for two full days .... Well, we started turning on normal flow for TPC gas last Thursday).

 

This afternoon/evening, I spent some time in 1008 room observing the TPC group (Tom, Charles, Evgeny and Luke) , John H., Martin, and Dan Cacace, completing the TPC test successfully.

 

Under Tom's and John's leadership, we have tried to do the most comprehensive TPC test (using the CAEN power supply and the long bundle of cables) that we can do in a very timely manner.  At the end of the test, we saw tracks successfully in the two sectors (611 & 612) in the North side of TPC in which we have installed the new equipment (along with other sectors).  One of these two sectors was pathologically bad before the repair/upgrade whereas the other sector had no defect.  

 

We have demanded this test to convince ourselves that the  TPC repair/upgrade scheme works and so we can start to prepare for the same TPC repair/upgrade for the entire TPC including both the North and South sides).

 

Now, we have reached this point and we will start to prepare for the South tomorrow (Nov. 22), which would (at some point soon) include taking out the MVTX.

 

 

Kin Yip

 

 

PS:

 

During the few hours in 1008, I also copied the "2023" files to the "2024" directory and we now have the "2024 run page" : 

https://sphenix-intra.sdcc.bnl.gov/WWW/run/2024/

 

Of course, I have changed only the "2023" to "2024" and the name of Run Coordinator on the above page.   Everything else has to be updated ...😅

Attachment: screenshot_for_firstTPCtracks.jpg
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