sPHENIX discussion of the superconducting solenoid

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

Hello,

 

The cool-down started yesterday and the significant/sharp drop (from ~60K) stopped around 4:30 pm at ~5.5K.   Now, it’s typically between 4.9 or 5 K.

Occasionally one may see some higher peaks.   It’s still not really stable yet.  Roberto explained:

“The fluctuations are from our 4K wave activities in the Blue magnet ring.

Until we get the 4K inventory densification "wave" recooler fill underway the R-line pressure will remain high and unsteady.”

 

Last year, when we got to around 4-5 K, the RHIC magnet has been stable for a week.  This year, we’re at the same status as the rest of RHIC.

 

Nevertheless, we (Carl Schultheiss, Theo Samms and myself) have done a hipot for the sPHENIX Magnet at 520 V successfully (leakage current ~ 0.1 mA => 5.2 MOhm).

 

Pablo Rosas and his teams are putting back things together and prepare for the ramp-up.

 

We’ll be consulting with Roberto when it’ll be good/ready enough for the ramp-up, hopefully tomorrow or Thursday.

 

Kin