sPHENIX discussion of the superconducting solenoid

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

Hi,

At 22:44 (July 20/Sat.), the magnet suffered from a fast-discharge due to 
"dump resistor water flow fault" --- first time in magnet history.   ( It 
lasted since ~8:59 am June 27. )

CAS called in C-AD mechanical support (Adrian and Travis) to help fix the 
"flow switch".   The initial effort didn't work out and Adrian/Travis are 
going back to their shop to try to find components to replace.  At the end, 
though they replaced orifice and other component, it seems that the dirt 
seemed to completely clog the orifice that they needed to clean it up.

The magnet ramped back to the top current at 5:17 am this morning.

Kin

PS:

The dump resistor is not involved when the Magnet is running and it's used 
only when we have a fast-discharge.

The interlock on the cooling water flow for the dump resistor cause the 
magnet to fast-discharge and therefore the ~23 MJ of energy goes through the 
dump resistor is self-damaging/self-destructive.    I've asked Pablo about 
this to see whether we can change this.   It should be just an alarm/alert 
(rather than an interlock) to let them know to try to fix it, instead of

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