From: Peterson <peterson@205.252.116.10>
Newsgroups: sci.physics.plasma
Subject: Re: Gas Plasma Impedance Vs Water Impedance Help!
Organization: Erol's Internet Services


Jason Huckaby wrote:
>
> Help
>
> I am ionizng Ar at low pressure (a plasma) and I am
> running into problems. The plasma is "captured" by a
> magnetic field. I believe that I am losing current
> that should be going into the plasma thru a water
> cooling system.
>
> Questions:
>
> I know my average plasma impedance seems to around 50ohms,
> does it initially have a higher resistance to start the
> plasma than once the plasma is formed?
>
> Does the magnetic "capture" field strength relate in any
> way to the plamsa impedance?
>
> I am using tap water, (and would like to continue to do so),
> but I mentioned, I believe that I am losing current through
> the the water cooling system. Is there a way to minimize the
> electrical loss two plates in water (one charged and the other
> at ground)?
>
> Any help would be appreciated!!
>
> Thanks!
Tap water is a pretty good conductor. Can you get deionized water and
use a closed loop recirculation cooler? That will help.

The resistance of your plasma depends on the extent of ionization, which
is a function of temperature. It can also be influenced by impurities
that get entrained in the plasma gas. We see that in our 150 kW
atmospheric pressure plasma torch reactor at the Naval Research Lab.

Steve Peterson