sPHENIX discussion of the superconducting solenoid

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

Title: sPHENIX Magnet LN2 cooling restarted last Friday

Hello,

Last Friday morning (Dec. 20), Dennis Donaldson and his colleagues found out that there were some mechanical problems with the new switch which probably got damaged during the transport.  They couldn't provide "Normal/Emergency" power.   The Cryo controls at 1010 were originally connected to "Normal/Emergency" power.  But with a bit of persuasion, Len Masi was able to start the compressor by using "Normal" power for both the compressor and the controls.  The LN2 cooling was restarted in mid-afternoon (Dec. 20).

During the week of shutdown (Dec. 16-20), Ken Riker replaced the leaking relief valve with a new one.  The frost situation is much better (as shown in one of the pictures below).  At least, there is no visible gas fume leaking.

I also attach a plot of the LN2 cooling since last Friday.   It's very obvious for the temperature sensors at both ends of the Magnet Extension but quite slow for the mandrel (MT01).

Kin

PS: The above is actually my entry in the sPHENIX Elog (of C-AD):  http://elog.pbn.bnl.gov:8080/elogs/entryList.jsp?ELOG=sPhenix&PAGE=1&ELOGTYPE=Project#1954492

From: Yip, Kin <kinyip AT bnl.gov>
Sent: Friday, December 20, 2024 7:08:54 PM
To: Than, Yatming (Roberto) <ythan AT bnl.gov>; Sampson, Paul <sampson AT bnl.gov>; Chan, David <dchan AT bnl.gov>; Reilly, Kevin <kreilly AT bnl.gov>; Vogt, Lawrence <lvogt AT bnl.gov>; Albanese, Marianna <malbanese AT bnl.gov>; Hanson, Cory <chanson1 AT bnl.gov>; Lederle, Dewey L <lederle AT bnl.gov>
Subject: RE: Will this affect your compressor : RHIC 1010 area power shut down plan. 12/16~12/20

 

Hi,

 

In case you wonder, it worked out at the end.

 

At 1010, after lunch, before Dennis and I found Len Masi and his colleague, Len actually already powered up the control system in 1010 by plugging to the Normal power.  He didn’t

really need the help from Dennis.  ( In retrospect, he could have done so 2 days ago. )

 

The Cryo group tech turned on the compressor and restarted LN2 cooling in mid-afternoon for sPHENIX Magnet in 1008-IR.

 

My little push worked out today; otherwise the Magnet won’t be cooled for quite a while. 🤔

 

Kin

 

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