Hi Junfeng,
May not be too helpful here.
Sorry, I am little confused about your dual system setup.
First, my understanding is that two different shim files are used for the
wide-bore shim and standard-bore shim stacks.
Secondly, the wide-bore shim stack is temperature controlled by running water
through a separate chiller. There is no flush gas involved in the wide-bore
micro-imaging shim stack. The flush gas is mainly used for the probes,
particularly for low and high VT in NMR, as far as I know.
Just my 2 cents.
Good luck.
Simon
________________________________
> From: main_at_ammrl.groups.io on behalf of Ïò¿¡= ·æ via groups.io
> Sent: Saturday, May 23, 2026 3:55 AM
> To: main_at_ammrl.groups.io
> Subject: [AMMRL] problem about shim coil temperature control in two shim system
Dear Colleagues
Recently, we have faced one problem which come from the temperature control
in two shim system of Bruker NMR spectrometer. We have a wide-bore 500 MHz
magnetic for microimaging as well as high resolution liquid NMR. To realize
these two functions, two shim coils have been provided: one for microimaging
and another for high resolution. When the NMR spectrometer was setup, the
Bruker engineer try to use the shim coil of microimaging for everything,
everything looks fine thereafter. But years later, high resolution could
not be achieved because of some unknown reason. We have to switch to the
shim coil of high resolution. An unexpected problem occurred during the
low-temperature measurement. When the sample temperature has dropped to
-60 oC or below, a warning message appear that "the shim coil temperature
is too low£¨lower than 5 oC£©£¬then the experiment is stopped
by the topspin. We have checked the setup for gas supply in the webpage,
nothing wrong was found. Shim coil gas is normal and we can hear the gas
sound. We have consulted with local Bruker engineer for help. They said this
problem may be due to no gas flow for the new shim coil and they could not
provide a good solution. I wonder whether anybody have similar experience
which could let the flush gas work both for the two shim coil.
Best wishes
Junfeng Xiang
ICCAS, Beijing China
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Received on Sat May 23 2026 - 08:19:28 MST