Glow Cleaning: How to ??

[Mark Rowley]

What exactly is "glow cleaning" and what are the procedures on how to do it so you can lower your vacuum in a bell jar system ?

Advanced apologies if this has been discussed before. However, I just cant seem to locate the thread.

Mark Rowley

[Roberto Ferrari]

Mark,
Surely there are other alternative procedures but just 100 microns of dry gas and 200/300 DC V @ no more that 100mA will help a lot.
Check Sam's Laser FAQ for typical laser tube processing.
Roberto

[Roberto Ferrari]

Mark,
The Search option got me to a better and detailed procedure by Dave Cooper (The "Drydown Zone" R/D magazine), posted 2003-12-23, 01:32.
Roberto

[Roberto Ferrari]

Mark
Here we go again. I forgot your question about what is "glow cleaning".
It is related to "glow discharge" condition. Gases at low pressures under high voltages go into a ion conduction discharge. (See "Paschen's law"). Under this condition you apply energy to all the inner surfaces helping to release all sort of substances and gases adsorbed. This procedure is specially good to release water, the all present ghost in high vacuum systems. Large pumping sessions and heat helps a lot to clean vacuum systems. Glow cleaning shorts your time.
Richard posted Danielson's web site, an expert in high vacuum practices and a teacher as few remain. Look into it to learn a lot.
Roberto

[Mark Rowley]

Thanks Roberto. I knew the info was hiding somewhere.

Mark Rowley

[Richard Hull]

In glow cleaning mode you are turning the fusor into an ion pump of sorts. I used to glow clean for over an hour at pump down.

Richard Hull

[DaveC]

Key thing with glow cleaning, is to keep the voltage as low as possible and the current high...You want bombardment, not implantation. Also the pump should be on when you apply potential.

As your system cleans, the current will diminish, and the voltage will climb.


Dave Cooper