SUMMARY: EPR and NMR nearby?
Steve Philson (philson@nmr.chem.umn.edu)
Thu, 26 Jan 1995 14:47:12 -0600 (CST)
Many thanks to all those who replied. The consensus was that an EPR
instrument over 20 feet from an NMR would not be a problem. No one
actually had quantitative data, but there were quite a few experiences
with electromagnets around supercons, and almost all detected no
adverse effects. The one exception was a Jeol FX90Q 15 feet from a
400 MHz instrument; turning off the magnet caused lock to be lost on
the 400. Since the field at 20 feet from an EPR is probably an order
of magnitude less, and since our resolution requirements for the
solids are also lower by an order of magnitude, with the positive
experience of others in similar situations, I conclude we are probably
safe to at least try them in the same room.
A couple of people pointed out an aspect of this which I hadn't
thought of -- the fringe fields from each magnet will be mainly
perpendicular to the other magnet's main field, and adding them
vectorially will predict much less perturbation than just the
magnitude of the fringe field.
Once again, thanks for the help.
--
Steve Philson philson@nmr.chem.umn.edu
Director NMR Lab 612-626-0297
Chemistry Dept. University of Minnesota