[3dem] SUMMARY - icing with Gatan ELSA 698

[Tim Gruene]

Hello everyone,

thanks a lot for the great wealth of suggestions. Most suspect the
column vacuum and suggest a thorough column bake-out. Some suspect the
retractable holder tip, which can be checked with the pumping station.

I already contacted JEOL about their recommendations. The instrument
was installed in April this year, i.e. very recently.

We do have a custom made flunge for our detector (which we previously
used on our CM200 without problems). Maybe this is the source of the
leak (O-ring not quite in place, groove for O-ring too deep...).

It is new for me that a leak can be so small the microscope actually
operates. I don't have a record of the vacuum from the commissioning,
which was done without our detector. Maybe I am lucky an it is in one
of the documents - I will check asap.

Thanks a lot everyone - now I know better how to tackle the issue.

Best wishes,
Tim


On Fri, 21 Oct 2022 00:25:10 +0200 Tim Gruene <tim.gruene at univie.ac.at>
wrote:

> Hello erveryone,
> 
> our Gatan ELSA 698 holder produces ice such that we see the ice rings
> in the ED diffraction pattern. The ice evaporates at -130C, but
> returns as soon as we reduce the temperature again below about -140C.
> 
> This also occurs when we insert the holder at room temperature and
> only cool it once fully inserted into the TEM (JEOL JEM2100Plus)
> 
> Would there be any ideas for the cause of this icing, and maybe even a
> cure?
> 
> Thanks a lot!
> Best regards,
> Tim
> 



-- 
--
Tim Gruene
Head of the Centre for X-ray Structure Analysis
Faculty of Chemistry
University of Vienna

Phone: +43-1-4277-70202

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