sPHENIX discussion of the superconducting solenoid

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

Hi,

 

I just left 1008B mezzanine and Pablo’s colleagues (Tim & Chris) were still working there when I left. 

 

1. After we put in the old scaling factors from 2018 (high-field test), I saw on the pet/Logview, the two currents (Power Supply Current and Magnet Current, the latter from DCCT)
   were different by 1000 A or so (3800 vs 4800 or so).

 

Carl and Pablo’s team together found a couple other problems (like a missing connection to the DCCT rack).  At the end of the day, when Carl left, they agree well --- the current goes
through the dump resistor and so the real Magnet current (DCCT) observed would be always somewhat less than the Power-Supply Current.    Carl seemed happy.

Carl said that the only thing that he needs to do is wire the two voltage taps from the current leads to his board on the platform.

 

2. According to Tim and Chris, the real remaining issues are:
   (i) Ground fault reset --- which they are nearly resolving it when I was leaving;

(ii) PSI problem in the power supply --- this is important because we need this working so that we can ramp the magnet from the Pet page as we plan/want to.  Ralph Schoenfeld and his new colleague came
this afternoon to check that the wiring between the Quench Detection rack and the Power Supply are good.  This problem is inside the Power Supply.

(iii) Tim/Chris still need to connect the Pole-tip door interlock signals.   Joel Vasquez gave them a new and more direct path (so that there is no intermediate processor which may cause problem).  So, they
need to make these connections, too.

 

3. Jesse Fite (and Chris O’Shea) came to 1008-IR to meet with Russ Feder and me.   Jesse (from C-AD) was not satisfied with our sweep as there are too many “loose” metallic objects that he could find.  He said that
   we need to do it better.  We’ll ask people to clean up more and Russ said that he’ll walk with Frank over the 3 levels to “sweep better” 😊

 

 

So, even though we have run the Power Supply for more than 24 hours successfully (which is good !), we still need another day to finish solving the remaining issues, before we can connect the braids to the Magnet.

( We have to make Jesse Fite happy 😊 )

 

Kin

 

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