sPHENIX discussion of the superconducting solenoid

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

Powerpoint: https://indico.bnl.gov/conferenceDisplay.py?confId=4115):

 

 

1.       I mentioned that we had and completed an External Technical Review for the Cryo system in 1008 last Friday.  The reviewers came up with several recommendations.

2.      Hipot tests were completed and passed for the Magnet and even dump resistor at about 13-14 K (Coil temperature).  The one for the Magnet saw no current increase up to 520 V.

( For the dump resistor, it seems to have ~500k Ohm as an increase of 50 Ohm would increase 0.1 mA. )

3.      Dave Phillips told us that Rob Karl promised to finish making the copper bar support and connecting all the cables by the end of tomorrow (Thursday).

4.      So, the plan is that Mike Lenz will install the box on Friday.

5.      Paul Orfin reported that their effort to get the Magnet outlet back to the Plant (so that we may run continuously) failed ---- they tested it last night (~ 7 pm).  
So far, he’s been using very little flow into the system and running various tests.  He’ll test the flow seriously tomorrow and put in real liquid He.  Then he can
calculate how much consumption the system will be and figure out how long we can run the Magnet.

6.      Carl et. al. were worried about the temperatures at the splice (of the Extension) seems to be higher than others.  Yesterday, when coil temperature were 4.x K and others
5, 6, 7K, the splice temperature seemed to be > 20 K.   Paul Orfin told us that he had not really put in real flow and when more flow is put in, we shall hopefully see
improvement.   So, we’ll wait for his test tomorrow.

7.      People mentioned about strain gauge.  I’ve sent a couple of heavy documents to John Haggerty and he’ll try to compare the BaBar strain gauge values with what we had.
Then, we may come up with something to look out for strain gauges.

8.      Carl told us that he’ll need to do a few things:
-- investigate why the offset changed for his voltage tap channels (maybe after cool-down) ?
-- check whether there are interactions between channels
-- test the interlocks again with power supply
-- do resistance/inductance compensation

9.      Tentatively, if everything works out great, we can start working with the Magnet at 4.x K at 10 am next Monday (Jan. 22).   I’ve reminded people that we need to do a
few mundane things such as putting up the 5 G line and sign off all the items in the checkoff list before the test can really start.