From: adder_black_the@yahoo.com (Steve Ivy)
Newsgroups: sci.physics.plasma
Subject: Effect of rapid rise time B field on dense plasma?
Organization: http://groups.google.com/


Assuming one has a moderately dense plasma
contained in a moderate B field at some time.

And then one subjects that plasma to a very strong,
very fast rise-time, magnetic pulse say like
what would be accomplished by a "can crusher"
type single turn solonoid.

Even without the flying mass of a "magnetized
target" mechanism withs it's disposeable liner
couldn't one get a substantial compression just
using the B field acting on the plasma alone?

Most of the experiments that I have read about
that have attempted to create "magnetic bottles"
have tried to do so with superconducting DC type
coils. They were apparently trying to establish
a static magnetic bottle that would then
supposedly contain a plasma indefinitely.


I won't waste time on that since apparently most
everyone has given that up as a lost cuause.


Instead I will elaborate on some ideas I have
mentioned here earlier.


I am suggesting that this whole magnetic bottle
idea migh have gotten further if they had borrowed
more from the pulsed power school of thought.

I am not talking about the Z machine. That is a complex
disposeable mechanism and making it work on a
repetitive basis would be likely be tricky.

How about this instead.

Take a "high pressure" gas. Where "high pressure"
is undefined at this point but let's just say that
it is a significant portion of room pressure (or most
likely much higher).


Now if you want to effect that gas with a magnetic
field you will need it to be in a plasma state.


So you hit it with a very intense (laser pulse
,neutral beam or, microwave beam) So at least for a
brief instant you have a very dense and at least
moderately hot plasma.

Now you fire your main "can crusher" charge and you
should get a very hot very dense plasma that will
last at least a few microseconds.

Basically I say the heck with all the fancy efforts
at containment because a strongly riseing B field
will act to collect the hottest ions right as you
need them to be contained the most.

On the other hand a static B field will become less
effective at containment as the temperature of the
plasma is raised by whatever means (neutral beams,
microwaves or, laser pulse)

As the ions push out harder due to higher temperature
and gas pressure the magneti field will press that
much harder inward. All this happening at just the
right instant and no energy wasted maintaining or
heating the plasma before it is needed.


I suppose people have already tried this?

If so can anyone suggest any experiments I can
look up and see why this approach doesn't work well?


I realise that counter currents generated by the plasma
itself to oppose the rising external B field are likely
to be a big issue but it seems to me that an extreme
pulsed B field compression technique would be best able
to deal with that sort of counter reaction.

Also I don't see why one can't just create the needed
plasma right at the last instant in a dense gas rather
than wasting lots of energy trying to maintain it for
long periods time in less dense gasses?


Thanks for any pointers: Steve