Hi Anne-Frances
If you don't want to keep the magnet and are not in a hurry, as many have
suggested, the best way to do it is to let the magnet quench by itself.
Stop filling cryogens, and keep measuring the LHe level.
If you have the magnet book and the LHe sensor is still good, you should be
able to tell approximately when coils inside will get warm and start blowing
off LHe gas. Make sure you have good ventillation before it quenches.
Hope this helps and good luck.
Simon
________________________________
> From: main_at_ammrl.groups.io on behalf of Anne-Frances Miller via groups.io
> Sent: Wednesday, December 6, 2023 3:46 PM
> To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
> Cc: Anne-Frances Miller <afmill3r2_at_gmail.com>
> Subject: [AMMRL] planning to decommision a magnet that is too old to refurbish or give away
Dear AMMRL,
We have a very old round-bottom 600 MHz magnet from 1999 that I am told can
no longer be refurbished with any warranty, yet it is becoming too costly
to keep filled. Therefore I am planning to quench it, but want to do so safly.
Do any of you know of ‘instruction sheets' or guidelines available
for this rare procedure?
In case you are willing to comment and correct, I will appreciate it:
my plan is to allow the He level to come down to ≈35% while keeping
up with N2 fills.
Remove all the hardware that is not related to the magnet itself (e.g. probe
etc, lower the legs).
Remove the sealing caps on the tops of the lHe reservoir and lN2 reservoir
so that there are unobstructed exit paths.
Attach a gaseous He tank to the port of the dewar vacuum space, with a low
pressure of He via a needle valve (and of course a regulator).
Crack open the valve on the vacuum space to admit He gas. (I could also fill
a large ‘bottle' with He gas and connect that, instead of a regulated cylinder.)
Promptly back away to a safe distance with good ventilation.
Many Thanks in advance,
and I will know that no advice provided mades the provider legally responsible,
Anne-Frances
Novel Meritorious Research (and teaching)
—•—•—•—•â=
€”•—•—•—•â€=
”•—•—•—•—=
•—
A.-F. Miller, Ph. D. (she/elle/sie)
University Research Professor
Professor of Chemistry
University of Kentucky
https://www.uky.edu/*afm/
Visiting Fellow,
Einstein Foundation of Berlin
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Received on Thu Dec 07 2023 - 06:51:15 MST