Dear All,
We have a 400 MHz spectrometer consisting of a new console and an older (20
years) narrow-bore magnet. Next year we are supposed to move the
spectrometer to a new location and thereby some questions have arisen.
1. What is the approximate lifetime of NMR magnets? What are the most
important factors (except keeping the vacuum good and not dropping the
magnet during the move!) influencing this lifetime?
2. If there is a lifetime not much longer than 20 years, in which way does
the performance of the magnet suffers? Stability, homogeneity, more quenches?
3. Moving a magnet cold is cheaper. On the other hand, one hears that
moving a magnet warm is safer. Does this mean (i) safer for the persons
moving the magnet or (ii) safer for the magnet as concerning its
performance after the move? Can anybody direct us to some written
instructions or checklist about moving NMR magnets?
4. The 400 magnet has been performing extremely well in the past. Any
experience concerning the behavior of magnets after warming up, securing,
re-pumping, and re-charging? Does one usually get back the same performance
on such an old magnet?
Answers and suggestions will be compiled and distributed. The eventual
first prize for the best suggestion (in case we do not follow it and
thereby render the magnet broken) is a shiny cylindrical object that cannot
be magnetized any more but it is still sufficient to use as garden pond or
as a pot for larger till medium-size palm trees...
Sincerely
Istvan Furo
************************
Dr. Istvan Furo
Division of Physical Chemistry
Department of Chemistry
Royal Institute of Technology / KTH
Teknikringen 30/36
SE-10044 Stockholm Sweden
Tel: +46 8 7908592
Fax: +46 8 7908207
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