From: "nwaivio" <nwaivio@comcast.net>
Newsgroups: sci.physics.plasma
References: <bfsjhb$f486$1@saturn.cs.uml.edu>
Subject: Re: Need help with a microwave plasma deposition problem.
Organization: Comcast Online


10-100 Torr seems to be relatively high pressure.
the higher pressure would cause a more prevalent skin effect to
only heat the surface of the plasma. I am not sure a magnetic
field would confine the plasma away form the surface of the
tube. Perhaps different tube materials would help things or
a different tube geometry where the plasma would come into
contact with the tube less. I know that in many of those higher
pressure devisees they would use vortex stabilization or
other fluid mechanical techniques to isolate the plasma away
from the tube but with something like that you may need more
power :). When you use these techniques you must remember
your heat transfer in fluids and that to sustain a plasma the temp
must be upward of about 5000K. Some times starting with a
low pressure then bleeding it up works. All depends on your
setup.

Plasma Engineering: Where you listen to a theory guy then try
a million different things until it works or the money runs out.
Of course the setup breaks alot too and that needs to be fixed
costing more time and money.

Nathan.



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