RE: starship-design: plasma sources

["L. Parker" <lparker@cacaphony.net>]

Strictly speaking, oxy-acetylene (or any standard welding apparatus) is not
a plasma. There are, however, commercially available plasma torches. They
are quite expensive, but not as expensive as a commercial laser welder for
instance. A lot of work has gone on recently using RF heating as has been
previously mentioned. In fact, the only system that meets the definition of
high impulse and high thrust that is anywhere near operational testing is
based on RF heating (it is a huge microwave tube heating a standard
magnetically confined plasma). If you are experimenting on these lines, look
for information on VASIMR, however, I have found that a great deal of what
WAS posted on the web has been censored...and is no longer there!

Lee Parker

> -----Original Message-----
> From: owner-starship-design@lists.uoregon.edu
> [mailto:owner-starship-design@lists.uoregon.edu]On Behalf Of
> N. Lindberg
> Sent: Friday, August 20, 1999 9:40 AM
> To: Paul-V Khuong
> Cc: Starship Design
> Subject: Re: starship-design: plasma sources
>
>
>
> On Thu, 19 Aug 1999, Paul-V Khuong wrote:
>
> > Kevin Houston <Kevin@urly-bird.com> wrote:
> > > I tried the microwave method, and it's pretty cool,
> > > but I worry that it may
> > > damage my 'wave.  Isn't a plasma not very different
> > > from a piece of tinfoil
> > > in this respect?
> > Yeah... Good Question!
> > Especially when you live at your parent's place 8)
> > > At 09:48 AM 8/19/99 -0700, N. Lindberg wrote:
> > > >Fred,
> > > >	I'm no expert on plasma physics, but here are some
> > > ways that
> > > >immediately spring to mind:
> > > >	1) Spark gap + RF heating of the air.  Plasmas
> > > couple very well to
> > > >RF, and most of the energy gets turned into heat.
> > > >	2)High temp combustion + RF.  Sometime, bend a
> > > toothpick so that
> > > >it stands with one end pointing up, light that end,
> > > and put it in your
> > > >microwave. I think they're kind of pretty.  Also,
> > > the Oxy-Acetylene
> > > >reaction is the hottest type of combustion I know
> > > of, at a few thousand
> > > >degrees,  Kind of dangerous stuff though.
>
> Paul,
> 	I'm not really sure if Oxy-Acetylene is a plasma by any strict
> definition. However, there is electron transfer occuring, and
> I wouldn't
> be surprised if the part of the flame where actual combustion occurs
> reacts to RF just like the toothpick.  Maybe try making a
> coil attatched
> to a transmitter and turn on the torch.
> Nels
>
> > Oxy-Acetylene is plasma???
> > Well, anyway, how energetic has the RF to be??(It'd be a cool
> > project... make your own plasma for less than 15 bucks(±))
> > And, how can you make the needed RFs(except than with a
> microwave 8)?
> > ===
> > Vive le Québec libre... dé souverainistes!!!
> >
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>