Dear group,
Many thanks to everyone who replied. Here is a summary:
There was a clear consensus that we should not move the magnets, if
possible. 23 people responded to my email, and of those, 13 people
thought that not touching our magnets is the best option. 3 people
thought that moving and refurbishing the magnets would be the best
option, 0 people thought that moving but not refurbishing was the best
option, and 7 people didn't offer an opinion.
The opinion, "don't move the magnets", in addition to being more
frequent, was also much more emotionally held. There were several
responses along the lines of "you should fight like hell not to move
them". There were also several people that cautioned me about Magnex
magnets in particular. Apparently Magnex magnets have a reputation for
not coming back to field after a warmup. Also, several people cautioned
against moving the magnets cold - the vibrations can stress the vacuum
seals, which could lead to a vacuum leak, or change the lay of the coil
windings, which could lead to problems trying to reenergize the magnet.
Bottom line: moving cold and refurbishing both have significant risks.
"Refurbish the magnets" was held as the best option by only 3 people,
but as the 2nd best option by many people. Our magnets are very old (one
is 20 years old and has never been refurbished, and the other is ~32
years old and was refurbished 23 years ago), and the seals may not last
too much longer. This would be an opportunity to have the seals replaced
and to reset the age of the magnets. I didn't get any stories about
magnets that were too much older than 20 years, so clearly we're already
pushing the limits.
A couple of people stipulated that refurbishing was a good idea only if
the magnets had come to field initially with no problems (ie - no
training quenches). In our case, both magnets came to field on the first
attempt.
Seven people had no definite opinion about what we should do, but
offered some advice about how we should proceed if we do decide to move
the magnets. Two of these were vendors, who helpfully offered to assist
with any moves or refurbishing that we might decide to do.
Thanks again to everyone. This was extremely helpful!
-Robert
-------- Forwarded Message --------
Subject: AMMRL: moving/refurbishing older NMR magnets
Date: Wed, 27 Apr 2016 15:09:24 -0700
From: Robert Peterson <peterson_at_mbi.ucla.edu>
To: AMMRL <ammrl_at_ammrl.org>
Dear group,
I have some questions about moving (and possibly refurbishing) old magnets.
We have 2 old NMR systems that we're considering moving into a different
room. The magnets are:
*600 MHz: installed in 1996 by Bruker, Magnex magnet, currently an
Avance III HD.
It has never been refurbished.
*500 MHz: installed in 1986 (it was a GE GN500, manufactured ca.
1984), currently
a DRX. It was refurbished once in 1993.
The magnets are both extremely stable. The boiloffs haven't changed one
bit since they were installed. Incidentally, both have cryoprobes and
are workhorse instruments for bio-NMR.
The move is basically optional. Some of the faculty here want to do it
because it would make things nicer for their research groups, but
nothing would be disrupted if they left the magnets where they are.
At the moment, 3 options are being considered:
1) Don't touch the magnets. Just leave them where they are.
2) Move the magnets into the other room.
3) Move the magnets into the other room, and refurbish them.
(If we move them, we will de-energize them and move them cold)
How advisable do you think options 2 and 3 are? Are there any opinions
about moving and refurbishing vs. just moving them? I know there's a
possibility that if you deenergize an old magnet, that it might not come
back to field. Does anyone have a good idea how likely that is?
Or a related question: if you have an NMR magnet that is 20+ years old
but that shows no signs of aging, and you have the money to refurbish it
- should you do it?
Thanks in advance, and I will post a summary of the responses.
-Robert
--
-----------------------------------------------
Robert Peterson, Ph.D.
Facility Manager - NMR Technology Center
UCLA-DOE Institute for Genomics and Proteomics
UCLA Dept. of Chemistry and Biochemistry
phone: (310)825-1816
fax: (310)825-0982
peterson_at_mbi.ucla.edu
-----------------------------------------------
Received on Tue May 03 2016 - 12:50:45 MST