Newsgroups: sci.physics.plasma
From news@newsstand.cit.cornell.edu Fri Feb 3 00:06:38 1995
From: mac5@cornell.edu (Marc Cohn)
Organization: Cornell University
Subject: Re: onset of plasma effects

In article <3goegg$rhf@mojo.eng.umd.edu>, ggraef@alpha1.csd.uwm.edu (Gerald Luther Graef) says:
>
>Suppose we could fill a box with ionized hydrogen. Should we expect
>to see plasma effects at room temperature? If not, does anyone
>have a general idea of the temperature necessary for macroscopic
>effects to manifest? Or do we have to wait until kT = binding energy?
>
>Thanks...Gerry
>

There are several factors that would contribute to the critical temperature
at which macroscopic effects occur. The mean free path of each ion would
have to be large enough as well as the mean time between collisions
so that the attractive potential doesn't force the ionized H to return to
its gaseous form. If your density is low enough or you add an excitation
energy externally (for instance, the E-field in a neon tube) you may be able
to sustain such a plasma.