sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi,

1. When Carl and Pablo tried to turn on the power supply, they realized that there was no (cooling) water !   At least, the internal interlock of the power supply worked !
Apparently, during the last weekend, while the ODH system gave our Cryo colleagues problems, the fan blowing at 10 F also broke some water pipes.  The result
is that there is no deionized water for the power supply.   Joe Scaduto's colleagues knew about this (but just we didn't know until today).  They have been and are now
working to fix it.   They have found the obvious leaks which are not too difficult to fix; but after they fix those obvious leaks, they'll run the entire water system to see
whether there are other leaks in the skid, pump etc. etc.  which may take more time.  Joe kind of promises that they will get it fixed by next Tue. (even if he needs
to bring some guys during the weekend).  If we're lucky, it could be sooner.

Carl/Pablo tries now to do some as much interlock test (with the power supply control system) as they can now.  When the water supply is available, they can finish
the interlock test and the new ramp function (provided by John Morris).  


2. Nevertheless, Rob Karl and his colleagues will start to work on the MCM cables and support structure (for support and clamping the cables to prevent them from
moving down).   Mike Lenz will go there to meet with them to have some understanding so that everybody's works will be optimized.

We'll put back the short-circuit copper bar when Carl/Pablo can do thest short-circuit test again.  ...  ( There is also a hipot test which needs cables disconnected with the Current Leads.  )   There will be some connecting and disconnecting.  Rob told me that once their support system is built, it might be easier to connect and disconnect.


3.  It seems that the He Plant has more than 50% Liquid He ... Sometime tomorrow, they will have enough Liquid He and they'll try to switch to 4K cooling.  This would
cool the system to ~10 K in a couple days probably, ie. during the weekend.  Next Tuesday, the Cryo group can try to test their "return to the Plant" mode in cooling to 4K
to see whether they can run in that mode almost indefinitely.



Kin