sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi Piyush,

Have you figured out how to get the temperature from ohm or voltage ?    The ohm or voltage should be the same thing if you have "constant
current" (especially high-precision).

Paul Giannotti told me to look at 2.4.   So, in //bnl.gov/c-adnas/babar/Volume 2 DESCRIPTION OF COMPONENTS/2.4 GAUGES AND INSTRUMENT CONNECTIONS,

there is  the "2.4 Gauges & Instrument Connections.pdf"

There are 369 pages with many nos. and curves.   I'm not sure whether the latter stuff are relevant (as they refer to various instrument).

But on p.7-11,  they have 3 resistance and 3 temperatures (temperatures are 4.2 K to 77.4 K to 295 K).

I took a snapshot6.png.    Since there are 3 points, I can do a quadratic fit which almost looks linear (but not quite).   I show you the
fit on TT01.gif for TT01.

So, temperature (K) = a + b*ohm + c*ohm^2 and the following are the coefficients from my fit :

TT01: -1017.35 , 5.05676 , -0.00187896

TT02: -916.28 , 4.22621 , -0.000191854

TT03: -868.795 , 3.88358 , 0.000384459

I've assumed the resistances  are in ohm.  


I hope this helps.

Kin

Attachment: snapshot6.png
Description: PNG image

Attachment: TT01.gif
Description: GIF image