From: Arthur Carlson <carlson@ipp.mpg.de>
Newsgroups: sci.physics.plasma
Subject: Re: Help explain Floating Potential Oscillations
Organization: Rechenzentrum der Max-Planck-Gesellschaft in Garching
References: <78i90l$21c$1@jupiter.cs.uml.edu>



sbushman@students.uiuc.edu (stewart samuel bushman) writes:

> ... I'm seeing
> an oscillatory signal - the floating potential, to a first order,
> resembles a damped sinusoid. ...
>
> These oscillations (mostly the first big one) cause the theoretical
> equations to blow up, leaving me with a discontinous plot of ne and Te vs
> time. I can't really figure what the oscillatiions mean physically in
> the plasma, as I'm pretty sure the phenomenon is real. It has been
> demonstrated at different locations in the plasma and in triple- and
> single-probe setups (to ensure the other probes were not interfering
> electrically). The oscillatory signal is also highly repeatable (although
> it differs somewhat at different plasma locations, but that is to be
> expected).

I don't get it. A floating potential oscillation of itself does not
cause any problem with the triple or single probe equations. Is your
problem a spatial gradient of the floating potential? Also, are you
sweeping the single probe fast compared to all oscillations?

Art Carlson

--
To study, to finish, to publish. -- Benjamin Franklin

Dr. Arthur Carlson
Max Planck Institute for Plasma Physics
Garching, Germany
carlson@ipp.mpg.de
http://www.ipp.mpg.de/~Arthur.Carlson/home.html

As usual, if I am caught or killed, the Institute
will disavow any knowledge of my actions.