Hi there fellow spinlanders!
Here at UVM we are in the final steps of designing a new STEM building,
which will house the NMR facility on the ground floor. We have two
500MHz magnets, one that is shielded (no problem) and one that is a 1994
genre unshielded Oxford magnet (problem). In the original plans the
architects did not allow for enough floor-to-floor space to contain the
entire 5G stray field of this magnet. Above this magnet they have
designed an ADA-accessible hallway & entrance to the building, so
potentially wheelchairs, gas cylinders and floor polishers are going up
and down this hallway. Approximately 9" of the 5G dome would protrude
into the hallway above.
To eliminate this problem, the architects have proposed (don't laugh)
...a pit, about 18" deep. This is for a 1994 Varian Inova 500 system,
that ideally would be replaced in the next 5 or so years. The
architects are saying that the pit would cost 'zero dollars', so the
administrators and the folks sporting the bill are liking this proposal.
Through NMR people on this list, I was able to obtain a reasonable quote
for the design of a shielding plate, to be installed on the ceiling of
the new NMR facility. With this quote, I was able to convince the
powers that be, that a shielding plate would be the better way to go,
avoiding having to fill in the pit once we do get a shielded magnet (and
cost less money in the long run). However, some are having second
thoughts... so I am wondering:
Does anyone out there have such a shielding plate and how effective is
it? Have you measured the magnetic field above and below this plate?
Have you noticed effects on the lock level when shimming (ie. if there's
moving metal objects on the other side of the plate)? Also, if you have
such a plate, who did you contract to design and install it? ...and how
much did it cost?
Your response is very much appreciated! ...because life is much better
without pits! ;-)
See you in a few weeks at the ENC,
Monika
--
Monika Ivancic, PhD
NMR Facility Manager (A-212)
Department of Chemistry
82 University Pl.
University of Vermont
Burlington, VT 05405
(802) 656-0285 office
(802) 656-0279 NMR lab
Monika.Ivancic_at_uvm.edu
Received on Tue Mar 31 2015 - 06:16:58 MST