sPHENIX discussion of the superconducting solenoid

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

Hi,

We had an "operator error" (that we forgot that we put in 20 mV as threshold in order to cause a quench intentionally yesterday evening, and left it there => we

should set it back to the usual 50 mV) which caused us to quench-back just before 4000 A.   We scratched our head for a little while and finally realized

the mistake.

We ramped again shortly after 1 pm and we went to 4596 A (DCCT) --- with setpoint at 4620 A at 2:55 pm.   So, we started our 24 hour experimental run.

At the time of writing, Carl has just left 1008B mezzanine and I'm doing the shift from 4 pm to 12 am (midnight).  And John Haggerty will take the shift

from midnight to 8 am.  24 hours should end around 3pm tomorrow.

The picture attached is one from the C-AD broadcast page : https://cadweb.bnl.gov/dashs/Operations/BroadcastWeb/sPHENIX.dash that you can see

the current and temperature of a thermal sensor for the magnet now (and during the quench earlier today).

Around 3 pm, Chris O'Shea and I originally planned to measure field around the 4 gaps and put ropes around them to signify 5G.  Ed O'Brien came along

and later Mike Dany and Adrian Steinhauff also came.  Ed and Adrian just took the static magnetic field training this morning.   According to the training,

Ed said that there is no real restriction for 5 G except those people with medical conditions like pacemakers, until 600 G.  We don't really have 600 G outside

the magnet.  

We've all agreed that we put the 5G line like at where it's now (just outside the shielding block boundary) --- my original plan all along !  Thanks for Ed's intervention and persuasion 😁  We don't need to find additional ropes.  The 5G line now is both conservative and convenient.

After the discussion, Chris O'Shea and I also measured the field at the staircases going up to the platform, and we found at most 1.5 G (just like the platform).

Joel Vasquez talked with me and two of his guys may work at the upper platform until midnight. 

Kin

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From: Feder, Russell <rfeder AT bnl.gov>
Sent: Tuesday, October 25, 2022 1:29 PM
To: Mills, James A <mills AT bnl.gov>; Pontieri, Chris <cpontieri AT bnl.gov>; Hock, Jonathan <jhock AT bnl.gov>; Toldo, Frank A <fatoldo AT bnl.gov>; Albanese, Marianna <malbanese AT bnl.gov>; Vasquez, Joel <jvasquez AT bnl.gov>; Stoll, Sean <stoll AT bnl.gov>; Schultheiss, Carl <carls AT bnl.gov>; Rosas, Pablo J <rosas AT bnl.gov>
Cc: Yip, Kin <kinyip AT bnl.gov>; Fliller, Raymond <rfliller AT bnl.gov>; Steinhauff, Adrian <steinhauff AT bnl.gov>; Warkentien, Andreas F <andyw AT bnl.gov>; Michnoff, Robert J <michnoff AT bnl.gov>; Haggerty, John <haggerty AT bnl.gov>; Dany, Michael <mdany AT bnl.gov>; Sheth, Chintan <csheth AT bnl.gov>
Subject: Re: Daily Briefing on ongoing work

 

All

At 3 PM Chris O'Shea is going to meet up with Kin out at 1008 and formally mark off the static magnetic field safety boundary.  Once that happens access to sPHENIX will be allowed even when the magnet is at full field.

However, we also discussed suspending work today and overnight because the magnet is going to be taken up to full field for 24 hours.  If there are any issues with this penultimate test, we don't want people around.  This will give the magnet operations team the most flexibility to get out there and trouble shoot as well.

So...by the end of the day tomorrow access to sPHENIX should resume for all other work.  If the magnet needs to be ramped up again for any reason work can continue.

Russ

Russell Feder

Brookhaven National Lab

sPHENIX Chief Mechanical Engineer

https://www.linkedin.com/in/russell-feder-engineer-manager/

631-655-2491

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