X-Message-Number: 9520
From: Ettinger <>
Date: Sun, 19 Apr 1998 11:20:35 EDT
Subject: Cryostats

CRYOSTATS

A couple of quick comments on Paul Wakfer's Cryonet #9497:

First, the oldest CI fiberglass unit now in active use is, as John Bull says,
about 11 years old; but the oldest one we have (the first one built) is much
older and still available if we need it. (The capacity is only one full-body;
we will probably use it for other purposes.)

Second, the maintenance problem with MVE type units, as I understand it, even
in the absence of leaks or gross damage, is from the outgassing or even minor
permeability that very slowly degrades the very hard vacuum required. Unless
this has changed, at some point the vacuum must be hardened again, and the
procedure in the past, at any rate, was to bake it and add new getters. Of
course, this would require removal of patients. The ten year estimate of MVE
was undoubtedly conservative, and several units have served longer; the actual
rehabilitation time remains to be seen.

Third, Paul says all existing types will become obsolete with respect to new
vitrification technology--when and if successful--that will use storage at
higher temperatures than that of liquid nitrogen. (I believe something like -
135 C has been mentioned.) That is not necessarily true. We have preliminary
plans on the drawing board for fiberglass units that will employ liquid
nitrogen, but will nevertheless provide stable temperatures in the desired
range, and that will use less nitrogen than present types. To build and test
models is one of our many research projects awaiting implementation. (Yes, I
have heard that the "cold room" technology of 21CM is intended to apply to
preparation as well as storage, and perhaps they believe both must be
integrated; but that is another long story.) 

And that reminds me to remind members that research donations (tax deductible
if made to the Immortalist Society) will be used for many worthy purposes,
some of them not contemplated by any other organizations. 

Robert Ettinger
Cryonics Institute
Immortalist Society
http://www.cryonics.org

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