Hi,
Recently we've experienced "slow quench" on 600MHz/54mm Bruker UltraShield
magnet. During He refill the lock signal was lost, and we saw field
drifting few megahertz in short time. It happened almost a week ago, now
boil-off rate of Helium is stable, ca. 12% per day, but the field is still
very strong (although we don't have means to measure it exactly now). Does
anybody know how much time it can take for the magnet to stabilize (or
discharge completely), before anything can be done to bring it back? Has
anybody had experience with such situation? Any ideas what might be the
reason for the quench (the transfer line was ok and cooled down, there was
enough LHe in the transport dewar, and the pressure was within recommended
limits)?
thank you.
Alex
--
Dr. Alexander P. Golovanov
Department of Biomolecular Sciences
University of Manchester Institute of Science & Technology (UMIST)
P.O.Box 88,
Manchester M60 1QD
Tel. No: ++44 (0) 161 200 5814 Office
++44 (0) 161 200 5812 NMR room
Fax. No: ++44 (0) 161 236 0409
e-mail a.golovanov_at_umist.ac.uk
Received on Thu Mar 14 2002 - 17:40:46 MST