sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi Paul,

(1) I've just discussed with our Electrical Engineer in sPHENIX Magnet, Carl Schultheiss.  In short,  if you can buy a ceramic which can endure about 300 V, it should be OK.  Slightly longer story is as follows :

If you check Carl's talk about the Magnet, e.g.

https://indico.bnl.gov/event/6950/contributions/32241/attachments/25080/37363/DirectorsReview_10_16_2019_Final.pptx

Carl typically said 300 V.  But in reality, we've shorted ground in the middle, so it's generally -150 V and 150 V (half of 300V).

But in the some very weird scenario, we may lose the ground in the middle, then the max. voltage is current*dump_resistance (68 mOhm) => it's 4596*68E-3 ~ 313 V

or (5% higher 4825.8*68E-3 ~ 328 V .   But this would need a few weird things to happen at the same time esp. as this is the helium line and in principle, the current doesn't flow through it (unless there is a fault somewhere and the current has no other place/ground to go to).

Therefore, if you can buy a ceramic insulator which can endure > ~300 V (or 330 V), it'll be acceptable.

(2) The last one similar to this inside the Valvebox that Ray Ceruti helped replace can be found here on the Sept. 8, 2015 calendar piece:

https://brookhavenlab.sharepoint.com/sites/sPHENIXMagnet/External/Lists/Calendar/DispForm.aspx?ID=35

( More description on the meeting on Sept. 9, 2015 :

https://brookhavenlab.sharepoint.com/sites/sPHENIXMagnet/External/Lists/Calendar/DispForm.aspx?ID=34 )

That's why I know it's "10 mm" electrical insulator when I talked with Ray earlier in our "meeting" at 912.  Thanks Ray for his help and agreeing to help in the replacement process.

I've placed the pictures that you showed me here (to document this leak) :

https://brookhavenlab.sharepoint.com/sites/sPHENIXMagnet/External/Lists/Calendar/DispForm.aspx?ID=268

Usually nobody reads all these except myself.  ( But everybody can read. )

Kin