Elevated N2 evaporation rate

From: Eugene DeRose <derose_at_niehs.nih.gov>
Date: Tue, 01 Oct 2002 11:12:49 -0400

Dear all,

We have an Oxford AS600 magnet with a slightly elevated N2 evaporation
rate of 380 - 400 cc/hr (spec < 375 cc/hr). The He evaporation rate is
only 20 cc/hr. The drift rate is less than 1Hz/hr and the lineshape is
excellent. The warranty on the magnet is about to expire, and we are
concerned that the elevated N2 evaporation rate may indicate a poor
vacuum that will only get worse with time. I would appreciate it if
anyone with an AS600 magnet would let me know what the N2 evaporation
rate is on their magnet.

Thanks in advance,

--
Eugene F. DeRose, Ph.D.
NMR Laboratory Manager
National Institute of Environmental Health Sciences
NIEHS ITSS Contract
PO Box 12233, MD MR-02
Research Triangle Park, NC 27709
TEL: 919-541-1981  FAX: 919-541-5707
derose_at_niehs.nih.gov

Received on Tue Oct 01 2002 - 11:01:14 MST