sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Agenda and powerpoint : https://indico.bnl.gov/conferenceDisplay.py?confId=2241

1.  I showed the calculation done by Bob Lambiase on the extension during a quench.  He found that there would be an increase of only slightly over 20 Kelvin => which is OK :-)   

1.1 We further discussed about adding voltage taps and current-limiting resistance to the extension before/during the assembly.  During and after the meeting, it seems that we would like to add voltage taps basically at every joint and Piyush and Carl come to  2*5 = 10 voltage taps.   Talking with Paul Kovach, we should have flange there and we just need to figure out how the connections are made to the new DAQ system.

=> Piyush/Sonny will make sure that we will have the voltage taps/current-limiting resistance added to the extension;

   Paul Giannotti will try to figure out the connections from the extension ... to the DAQ system ;

   Carl will make up the electrical diagram .


2.  I mentioned and showed a couple plots showing the force distribution on the walls for the high-field test using Opera with Wuzheng's model and his instructions.   I used to be able to get the total force on each wall and now after a lot of help from Wuzheng, I can find the force distribution using Wuzheng's macro and the method of "maxwell stress" in Opera to obtain detailed force distribution on the wall.
 
3.  Paul Orfin mentioned that what we did to insulate the two Current leads during the low-field test may be too crude.  He wondered whether we can do better for the high-field test which is close to  the eventual sPHENIX configuration.   We're going to ask  Dave Phillips about this.

4. John Cozzolino showed a plot of deflection (deformation) which looks exaggerated but are only a few mils.   His figure can be found in the above URL/link.   He further said:

"But this value is certainly an underestimate of the actual deflections expected, because bonding has not been removed from many mating surfaces that should instead be in frictional contact.  Plus there are a few issues with the solid model that need attention. 

So please consider this as only a first pass and only for the purpose of demonstrating some amount of progress on my part.  Right now, I’m just happy that I even got the thing to run!"

 

5.  After the meeting, Zeynep, Carl, Piyush and myself went to the 902 lower production floor where his DAQ system is now --- which used to be the DAQ system for the low-field test.   In addition to Zeynep copying the entire Labview project of Piyush, we also discussed about the quench detection system & DAQ as well as the voltage tap issue.