From: j.wendelstorf@tu-bs.de (J.Wendelstorf)
Newsgroups: sci.physics.plasma
Subject: Re: abnormal arc mode
Date: Wed, 30 Oct 1996 13:11:10
Organization: IfS,TU-BS,Germany


In article <553jh5$p5c@ulowell.uml.edu> eckard blumschein <eckard.blumschein@e-technik.uni-magdeburg.de> writes:
>From: eckard blumschein <eckard.blumschein@e-technik.uni-magdeburg.de>
>Subject: abnormal arc mode
>Date: Mon, 28 Oct 1996 16:02:13 -0800


>Sudden mode transition is well known in plasma physics for decades, on
>principle. As a rule, one of the two possible in bi-stable operation
>stages is unacceptable in practice, and the hysteresis may cause
>instability. However, despite of practical importance, we have found
>rather a few papers on such phenomena. Since we have been dealing with
>arc welding, we performed research on transition from normal arc mode
>into an abnormal one and return, and we have found a lot of new stuff.
>Maybe, someone has similar experience.
>--------------------------------------------------------------------------------
Indeed, there are only few papers dealing with the underlying processes
responsible to mode transitions -- especially for arcs, not for fusion
plasmas. In general the overal stationary arc discharge is not easy to
explain and mode transitions mostly deal with electrode phenomena such as
the onset of evaporation or the change in the electron emission process
at the cathode.

If there are specific observations or questions it may be interesting to
discuss them!?

+----------------+---------------+---------------+----------------------+
|Jens Wendelstorf|Inst.of.Welding+TU-Braunschweig|j.wendelstorf@tu-bs.de|
+----------------+---------------+---------------+----------------------+

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