[3dem] small flashes in glow discharger?

[Andreas Engel]

Dear Tobias and all,
Thank you so much for bringing this up.
We all know that the glow discharge (GD) has a tremendous influence on the
grid quality. One key reason for failure is a dirty glow discharger,
contaminated by hydrocarbons broken down by the plasma. This is creeping up
on us, as oil contamination takes time - Wim gave excellent counter
measures.
We also know what the best GD time is and what the mA should be for a
specific GD system. Comparing different systems, we should know the
electrode Ø to calculate the plasma current density, which I presume to be
a reasonable parameter for the plasma intensity. The geometry is
certainly important, but not easy to nail down. At least all systems look
similar.
According to my measurements, the top electrode of the GloCube has a Ø=55
mm, the EasyGlow a Ø=122 mm.
I would highly appreciate these values and those of other systems to be put
together.
All the best
Andreas



On Tue, Jul 16, 2024 at 2:57 PM Tobias Furstenhaupt <furstenh at mpi-cbg.de>
wrote:

> Dear colleagues,
>
> we use the PELCO easiGlow to glow discharge our grids before plungefrezing
> (and for other uses) and pretty happy with it. But we noticed small flashes
> from the bottom (see attachment - sorry for the unstable focus). Cleaning
> with ethanol or isopropanol has no effect. Also the metal in this area
> looks less shiny and potentially has now a slightly rougher surface.
> The quality of the glow discharge on our grids seems unchanged. Has
> anybody experiencied similar things and should we be worried?
>
> cheers
> Tobias
>
> PS: if the attached video does not work for you, here another version:
>
> https://urldefense.com/v3/__https://owncloud.mpi-cbg.de/index.php/s/ox67qdfPrREwrDn__;!!Mih3wA!BNvMHT2jzp_k9qHObg52qygdEWsHhp4-R065xzSAIV9B9qL0fXMnbJhrdBXxSoKtDvoCYoUwjjLBzARFAovGysA$
>
> -----------------------------------
> Tobias Fürstenhaupt, PhD
> head of Electron Microscopy
> Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)
> Pfotenhauerstrasse 108
> 01307 Dresden, Germany
>
> mail: furstenh at mpi-cbg.de
> phone: (+49) (0)351 210-2690
> cell: (+49) (0)176 / 44498706 (NEW!)
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>


-- 
Andreas Engel, PhD

andreas.engel at unibas.ch
andreas.engel at cryowrite.com
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