Hello all, we have had ongoing intermittent conflicts with a physics lab next door to our NMR facility. The architects of our new science building initially sited our instrument too close to an elevator. A reassignment of rooms placed the NMR facility adjoining a physics lab where instruments are reportedly perturbed by stray fields. This was not noticed until the plans were baked in, and the physicist has been upset about it ever since.
Yesterday I was informed that the physics department is requesting we quench the NMR for a month this summer so the physicist can calibrate one of the instruments in the adjoining lab (this is what I mean by "ongoing conflicts").
Disregarding the questionable logic of such a request, I need to identify risks of the proposed plan and ideally some alternative paths forward. I know some relevant information, but this excellent forum is my go-to for higher order questions about magnetic resonance. We need to make the strongest case we can that quenching is Not A Good Idea, because otherwise we may be given no choice except to quench.
Risks:
I understand that any time a magnet is quenched, it may not be able to be brought back to field. Is it also true that quenching can potentially shorten the lifetime of a magnet/make it more susceptible to spontaneous quenching?
I also know (the hard way) that after a quench, the magnet is relatively unstable and needs frequent re-shimming.
History of this instrument: put in service 2010. Quenched by accident ~2016 when a fill jockey was driving too fast. Quenched again intentionally 2018 for a warm move to our new science building (warm was recommended by Bruker to ensure no residual ice dam after the prior quench).
Alternative ideas:
My initial counter-proposal was to request that the college separate the two labs: relocate either the physics lab or the NMR facility to a different room. This is the only path I see as providing a long-term resolution to the conflicts. If our facility were relocated to a different room in the same building, I THINK a cold move would be an option. Does a cold move pose the risk of a quench? Are there other risks involved in a cold move that should be considered?
Another idea was to cold-move the magnet to storage for a month, then cold-move it back. I don't like this because we still have the problematic adjacency, and likely conflicts with physics in future. But if that's as viable as a single cold move, it would help to know so we can include this in the options.
Does a cold move require the same extensive re-shimming like what is needed when a magnet is brought back after a quench?
If moving:
We designed the new facility with Bruker's site planning guide ( care taken with ductwork, sprinkler and piping placement, ceiling height, etc. etc.). We won't be able to retro-fit a new room to EVERY specification, so I'm wondering: what are the mission-critical parts of a room to enable it to house a 400 MHz Ultrashield Plus NMR? I'd nominate the following, but there might be other things I'm missing:
* no less than 8m from an elevator (from site planning guide)
* adequate ceiling height for rigging
* adequate air exchange (per site planning)
* doors opening outward
* "adequate" spacing from pipes, ducts, etc. and not under a sprinkler head
And here we reach the point where I know there are more questions I should ask, but I don't know what they are....other feedback/suggestions/cautions are welcome. Thanks to all, and happy spring.
Heather Schenck
hschenck_at_uwlax.edu
Received on Wed Mar 01 2023 - 09:27:51 MST