sPHENIX discussion of the superconducting solenoid

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

Hi,

 

Today (before noon), we’ve switched to the He Plant cooling and from my attached plot, you can see that the temperatures of the Coils

are dropping at a rate of 1-2 K/hour (quicker at later hour).  They’re now at ~80 K.

 

Carl/Pablo have tried to ramp up the power supply with John Morris’ function (in pet page) using a short-circuit.  They met a problem

of false interlock of water leak in the dump resistor which was due to a bad “mat”.  Pablo and his colleague have replaced the mat.  Later,

they couldn’t quite ramp  … When they left ~4:30 pm, they believed that they had solved the problem but they needed to test it again

tomorrow.  Since Rob Karl’s guys didn’t seem to come to 912 to work on overtime tonight --- at least by 6 pm (Rob was not sure about

tonight … but more sure tomorrow night and Sat.), Carl and Pablo should be able to continue and hopefully finish their “ramp” test.

 

Kin

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