>1. How long is the (insulated) air line which runs from your heat exchanger
>(with isopropanol, etc.) and the probe?
We do not use any isopropanol, etc. We use direct cooling of
the Nitrogen flowing past the 26 in. cold finger which is
stuck in an insulated 1/2 in. dia. rigid "L" copper tube bent
90 deg. so that it rises to near the probe. Thus, I have less
than 1 ft. of air line going to the probe, and most of that is the
Varian provided glass vacuum line. The original version
of this design I am using came from Sykes' lab.
>2. How far from the magnet do you have the CC 65 II box?
9 ft. This is a special model of the CC-65-II called part number
225103230602
>3. Is the hose and/or cold finger non-magnetic?
Yes. Furthermore, you can make the cold finger longer by
removing some of the insulation since the cold finger is
merely the end of the hose. I would also recommend adding
a layer of 1 1/8 in. ID, 1/2 in. wall insulation to the hose
over the thin Neslab-provided layer.
-- Bruce D. Ray bray@indyvax.iupui.edu Operations Director NMR Center IUPUI Physics Dept. 402 N. Blackford St. Indianapolis, IN 46202-3273