Hi,
many thanks for all the responses and especially the deep inside
from Jerry Hirschinger and Yong-wah kim.
The reason for our quench finally with a very high probability was lack
of nitrogen. It's not fully reproducibility, but it looks like, the magnet
became filled, but during the filling procedure the storage dewar became empty,
but the mark about the filling already was done. Later no new storage dewar
was used to add the remaining nitrogen.
But beside this bad story we should have seen this within the log files!
Indeed we see ... if we use the correct logfile.
The full story is a little bit longer.
To monitor a bunch of different parameters - helium level, various temperatures,
lock level, ... - we use munin. A very easy to configure software with a rather ugly
web interface, nevertheless very helpful. munin does nearly all work, you have to
take care how to get the parameters. For this purpose munin uses so called plugins.
That are rather short scripts.
To get the helium level you have some possibilities. One is a direct contact with the
BSMS. For this purpose you might use the programs rstest or bsmsclient. Both are
rather debugging tools and maybe not the first choice to get some parameters in a routine
way. Even more, rstest resets your BSMS keyboard (if you still have one ...).
The easiest way is to extract the values from the file heliumlog.
This file is located within
/opt/topspinxy/prog/logfiles
for TopSpin up to 3.0 and in
/usr/diskless/pro/logfiles
for all newer releases.
Our spectrometer uses TopSpin 2.1 and our munin plugin looked for
/opt/topspin21/prog/logfiles/heliumlog
Tentatively a few days before the quench we tried to install TopSpin3.2. This failed,
we reverted everything. Well, not everything ....
The trial installation changed the creation of logfiles to the new destination mentioned above,
but the munin plugin still was looking at the old position. There was no more change, so munin
always read the last level a few days before the quench.
The logfile at the new position was fine and showed everything. :-(
BTW: the 26 year old sealings were in a very good state. I was really astonished. Nevertheless the magnet
contained a lot of air and water, which diffused inside during the couple of the last 26 years.
Once again thank you for all responses, even if I didn't list all names.
Rainer
Received on Tue Feb 18 2014 - 09:16:21 MST