sPHENIX discussion of the superconducting solenoid

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

Hi,

 

I noticed that Tim and Chris came in to work on 1008B mezzanine at 7 am … as I called, though they had monitor problem for a bit 😊

 

First of all, they told me that they had solved the “ground fault reset” problem last evening.   When I visited them, they wanted

to ask for help from Ralph Schoenfeld’s group.   I found Ralph and he sent Peter Zimmerman to 1008B to help.  

 

Long story short, as John Morris’ hunch, the two cables for the two PSI modules (one for driving the setpoint and the other for readback) were swapped by mistake.

After swapping back, we started to get readings.   Pablo adjusted some reference …

 

I left 1008B mezzanine when Pablo and his colleagues were taking a break.  They’ll connect the pole-tip door interlock signals and then test everything (with the

pet page ramp) together again.

 

When I asked Pablo whether he could sign off on the check-off list after that, he said “he’d think about it” 😊

 

Meanwhile :

 

1. Pablo told me that the Lab. LOTO experts are talking with Jon Sandberg and Ray Fliller about the way CAS pass the lock from one shift to another --- which is something that we have been doing in C-AD
   for years.   The Lab experts may want it to be one person… I hope Jon and Ray will help us sort this out.  ( We don’t need this before we can connect the power supply and magnet. )
   
   
2. The Cryo permissive signal --- which we need only when start ramping up the current and not afterwards --- seemed to drop to bad status sometimes.  From Brian van Kuik and Roberto Than, the permissive
   signal would be good after it’s been > a certain flow rate for 30 seconds.   They’re trying to figure it out whether it’s some noisy readback or something …

 

Kin