sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi,

From his message, right from the first sentence, it's clear to me that they didn't enforce any soak time for the reasons that Wes has explained.
6 hours is something that he made up in this email that it's good/nice to have, not that BaBar waited for 6 hours each time it started to inject high
current.  Carl would like to wait for 24 hours if possible/practical.

Kin

On 01/18/2018 10:36 AM, Phillips, David B wrote:

Kin,

 

Not sure I would interpret Wes saying “I would guess an extra 6 hours would be prudent” as not worrying about soak time.

 

Dave

 

From: sPHENIX-magnet-l [mailto:sphenix-magnet-l-bounces AT lists.bnl.gov] On Behalf Of Kin Yip
Sent: Wednesday, January 17, 2018 5:26 PM
To: sphenix-magnet-l AT lists.bnl.gov
Subject: [Sphenix-magnet-l] Fwd: RE: How long did you soak the Magnet before running high-current ?

 

Hi,

It seems that Wes and Pasquale didn't worry about the "soak time" too much.  They suggested checking the "thermometers" for
temperature stabilization.   I attach the reply from Wes Craddock and Pasquale below.

Kin

-------- Forwarded Message --------

Subject:

RE: How long did you soak the Magnet before running high-current ?

Date:

Wed, 17 Jan 2018 21:18:02 +0000

From:

Craddock, Wesley W. <wwc AT slac.stanford.edu>

To:

'fabbric' <pasquale.fabbricatore AT ge.infn.it>, Kin Yip <kinyip AT bnl.gov>

We didn’t really spend much thought on soak time for the magnet once it was filled with LHe.  In part this was because there are a number of hours involved in filling the magnet storage vessel in the valve box and checking out the magnet (voltage test to ground, looking at magnet position, etc.).  If there is residual heat in the magnet, it will be difficult to fill the LHe pot.   Also the two magnet layers are mostly high purity aluminum with high thermal conductivity. 

 

I would guess an extra 6 hours would be prudent, but as Pasquale points out the best thing is to look at temperature sensors.

 

Hope this helps.

 

Wes

 

From: fabbric [mailto:pasquale.fabbricatore AT ge.infn.it]
Sent: Wednesday, January 17, 2018 12:28 PM
To: Kin Yip; Craddock, Wesley W.
Subject: Re: How long did you soak the Magnet before running high-current ?

 

I only participated at the magnet commissioning and this question
was not raised. However there are thermometers on the coil
and  one can look at the temperature stabilization.

I think that Wes has much more experience on this magnet after years
of operation and can give a more appropriate answer

Pasquale


Il 17/01/2018 21:20, Kin Yip ha scritto:

Hi,

In the past BaBar operation (or whatever), did you guys need to soak the Magnet at 4.x K for   some nos. of hours before you put in high
current into the Magnet Coils   ??

Kin

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