sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi,

This afternoon, 5 of us (P. Joshi, B. Lambiase, I. Marneris, D. Phillips and myself) have had a very constructive meeting about
the power supplies.  I think we have sorted out a couple things :

(1) For the low-current test, for manpower concern etc.,  we'll use the power supply that Piyush already has in SMD which has been used
with 7 H in the past (so that 2.3 H for the sPHENIX solenoid is not a problem).  There we'll have interlock and put a 125 A fuse to
limit the current.   Piyush's system will have a data-logger which will read out the strain gauge etc.   Piyush has had good suggestions
that we will try to read out those 8 DVxx to understand the voltages and dI/dt etc.  He even contemplates that if time allows, he can
try to optimize his quench protection system during the low-current test (and this may take a few more days).

(2) For the high-current test, we have easily agreed that we'll install the PSI system on the SLAC power supply and use that PSI to control the
ramping of the power supply.  There will be communication between the power supply and the quench protection system, of course.   Piyush's
logger system will read out the same connections (strain gauge etc.) as in the low-current test.   If it's possible (like the manpower of C-AD)
and time permits,  we may even implement some interface between his quench protection system and the future control software system that we
may use for real sPHENIX ---- but this requires some work from C-AD control group and we're not sure whether it's possible in our time frame.


Kin