From dortwegt@aps.anl.gov Sun Mar 14 15:29:02 2004
Date: Mon, 16 Feb 2004 13:19:46 -0600
From: dortwegt <dortwegt@aps.anl.gov>
To: Douglas S. Robinson <drobinsn@iastate.edu>,
     Eric M. Dufresne <dufresne@umich.edu>, Thomas Gog <gog@anl.gov>
Subject: Thermal equilibrium of LN2

I spoke with each of you last week, and it was pretty interesting.  I 
wonder if you could all give me your thoughts on this:

The low pressure side of the cryo-cooler operates at atmospheric 
pressure.  Atmospheric pressure varies with the weather changes and 
could be on the order of as much as 1psig total variation out of 15pisa. 
 This would correspond to a temperature fluctuation in the low pressure 
reservoir of around 0.5 deg C.  Since the high pressure loop is cooled 
against this cold sink temperature, do you think the possible 
temperature variation of the low pressure sink is causing any thermal 
drift on your high pressure side?

I am very interested to hear your thoughts on this.  If you'd like to 
phone, that is no problem.  E-mail OK too.

Thanks,
....Bob (2-6058)

P.S....you can page me at 4-1740.