Hello:
We are looking for a new supplier of liquid Helium for our 200 MHz
Varian Magnet. We are considering 3 suppliers who provide different
grades between 99.999%-99.995%. I looked through our literature and
couldn't find any specs from Varian suggested purity. I understand
that having the purest Helium is best for maintenance; however, we
need to consider the cost different for 30 liters $197 (99.995%) vs.
$450 (99.999%).
So, What level of purity is acceptable? If you have used a lower
grade (99.995%) liquid He, how long have you gone without a
spontaneous quench? Or what have you heard considering lower grade
liquid He?
Thanks in advance for your replies.
Brian
--
Brian Myers, Ph.D.
Assistant Professor
Department of Chemistry and Biochemistry
Meyer Hall of Science (rm 258)
Ohio Northern University
525 South Main Street
Ada, OH 45810
419-772-2350 (voice)
419-772-2985 (fax)
b-myers_at_onu.edu
http://www2.onu.edu/~b-myers/
Received on Wed Nov 03 2004 - 12:01:21 MST