sPHENIX discussion of the superconducting solenoid

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

Hi Steve,

 

Thanks for the “new” conclusion that the “big card” (G10 board) is the problem.  ( I attach the PDF that I sent to Steve, with some more editing ------ each time I read, I find something wrong and worth editing, including my email. )

 

Kin

 

From: Plate, Stephen
Sent: Thursday, May 10, 2018 10:20 AM
To: Yip, Kin <kinyip AT bnl.gov>
Cc: Anerella, Michael D <mda AT bnl.gov>
Subject: Re: Anything suspicious ?

 

Kin,

My analysis that concluded earlier that the "big card" was not a problem assumed that the card was in good thermal contact with the bus bar.  After careful review of the pictures it was determined that such an assumption was no longer justified.  Therefore, I revised my conclusion and agreed that the method of attachment of the card to the bus bar is the primary contributor to the sensor reading high.  I believe the sensor reading is accurate for the card, but the card does not reflect the temperature of the bus bar.

 

Steve P. via Motorola Droid

"Yip, Kin" <kinyip AT bnl.gov> wrote:

Hi Stephen,

I hope you remember the occasion/discussion, that we have tried to figure out why the temperature sensors (RTD's) TT1786/1787 were like ~20K higher than the other two TT1788/1789, during our sPHENIX Magnet High-Field test.

I attach a PDF file.  At the bottom of the 1st page, there is a description ---I was trying to write a report and so I copied and pasted somebody's paragraph.  ( I had to modify a few typos such as from "raped" to "wrapped"  and adding "conjuctions" etc. )

>From this detailed description, do you see anything that may cause the big temperature difference ??   Since the Magnet worked, it had to be superconducting and couldn't be really at 25 K (instead of 5 K or so).    We've suspected the "big card" but Mike Anerella told me that your calculation doesn't believe that that "big card" should make a difference ???

Kin

Attachment: How RTD was mounted.pdf
Description: How RTD was mounted.pdf