From: adder_black_the@yahoo.com (Steve Ivy)
Newsgroups: sci.physics.plasma
Subject: Re: New Hybrid MM ICF Approach.
Organization: http://groups.google.com/
References: <a1hjom$a6hm$1@saturn.cs.uml.edu> <a1k4qr$13p4$1@saturn.cs.uml.edu>


Mike Rosing <rosing@neurophys.wisc.edu> wrote in message news:<a1k4qr$13p4$1@saturn.cs.uml.edu>...
> Steve Ivy wrote:
> > Fix # 1 (for the holes in the ends)
> >
> > Instead of jumping through endless hoops trying
> > to cap the ends magnetically why not just plug
> > them with a couple of powerful laser beams?
>
> Because the power level would require most of the
> energy from a 1 GW nuke plant. Photons have no mass,
> so they can't push very hard.
>
> > Fix # 2 (What to do about diffusion)
> >
> > I suggest we provide a set of electodes within the
> > solonoid. Picture a squirrlle cage assembly of non-
> > ferrous electrodes. lining the inside of the solonoid.
> >
> > Now sequentially apply a high positive voltage to each of
> > the electrode elements in turn. The electric field will
> > be be made to rapidly rotate about the cage. So any
> > positively charged particle that approaches the wall
> > will attempt to avoid the moving electric field.
> > But as the particle attempts to avoid that field
> > it will now have a tangential velocity component and
> > will thus be subject to the main magnetic field.
> >
> > This sort of arrangement will likely not entirely stop
> > diffusion but it should slow it to a rate where it is
> > no longer "a show stopper"
> >
> > One variation on this laser approach would be to apply
> > a long medium intensity laser pulse to the plasm
> > (to pack the plasma somewhat densely)
> >
> > Once the lasma is packed sufficiently dense one could
> > hit the plasma with a brief but very intense main pulse to
> > induce a propegating burn in the plasma.
> >
> > I would think that this approach is especially well
> > suited as an adjunct to the new "Magnetized target
> > fusion" program.
> >
> > Call it a Hybrid Magnetic Mirror Inertial Confinement Fusion
> > or (HMMICF).
> >
> > let people from both of the biggest and oldest camps of
> > fusion research work on it together. Peace at last.
> >
> > Thanks for any insight on where I have gone wrong.
>
> It's a funny name. I like it tho!
>
> The best thing I saw was a hybrid fusion/fisson reactor.
> Use the fast neutrons from an ICF to slam into a uranium
> blanket, and pump heat to generators, then recover the
> plutonium for regular nuke reactors. No plasma physics
> tho, so I guess that cuts out one group :-)
>
> There was an experiment done in the 1980's that had
> "baseball" coils at the end of a mirror to help confinement.
> It helped, but not enough to gain over the energy cost.
>
> The problem with ICF is also efficiency of the lasers.
> Once we can get really high power from LED lasers, building
> a fusion reactor might be possible. It's gonna be a while
> tho :-)
>
> Patience, persistence, truth,
> Dr. mike
>
> >
> > Steve Ivy

OK here go a few more wild ideas.

Stubborn as a mule, yes but hopefully not to
the point of beating a dead horse. I can only
hope not as dumb as an OX either. : )

I believe I now get your point about the B field.

Is the following true, energetic ions attempting to
escape the plasma (in a radial direction) by definition
have velocity in the radial direction? And thus are trapped.
(at least in the radial direction anyhow.) ?

If so then as they (attempt) to travel in the
outward radial direction they experience a lorentz
force across their path forceing them to move instead
sideways in an endless loop circling the central axis
of the solonoid.

OK since it appears that any movement radially
will be instantly circumvented by a sufficiently strong
magnetic field. It then appears that fast moving particles
escaping is not the mechanism by which "diffusion" occurs.

Yes?

Just thinking about it it appears as though it isn't
the fast moving ion portion of the plasma that is
the problem but instead that tiny portion of the plasma
population that is moving very slow. So slow in fact
that the B field really doesn't present much of an
impediment to it's motion. Yes?

Still talking about an ion's motion (in the radial
direction) it's kind of like the B field doesn't
really create a "magnetic bottle" at all but instead
(my analogy here) creates a thick viscous fluid through
which the ions must pass.

So continuing with the thick fluid analogy. Objects
attempting to move rapidly through such a fluid experience
large impeding forces but objects which attempt only to
move very slowly will only see very small impeding forces.


So if I my take on diffusion is correct I think the
key to eliminating diffusion would be to keep the slowest
moving plasma ions from slowly creeping outward.

You would only need to be careful of those ions nearest
to the outer wall because those are the ones in danger
of touching the wall.

Note that since they aren't moving fast to begin with
they don't really hold much of the plasmas energy but
if they did get out they will thin the plasma preventing
it from maintaining the required high density.

So with that in mind I still think a rotating E field
cycled around the wall to sweep up the lazy ions might
be a good idea.

But seeing as inspiration has just struck how about this
idea instead.

Since you want to keep slow moving away from the wall you
could spray a cylindrically shaped beam of very fast moving
neutral particles parallel to the solonoid wall. This fast
moving curtain of particles will interact with the slow
moving ions encroaching on the wall. That way no ions

It is late so let me know if any or all of that was dumb.


Oh well enough about diffusion for how. How about the lasers.


Well I didn't pull the laser initiated gaseous plasma fusion
idea out of thin air.

I know that not too long ago some group announced that they
had generated fusion and had measurable neutron flux coming
off of it.

They just fired an intense laser beam through an excited plasma.

That was about all there was to it.

So I know the basic idea works at least a little bit.

All I am adding is the additional elements of magnetic
containment and lasers coming in from both sides.


I hadn't meant to imply that one could try to trap the ions
with "laser tweezers"

It's the photon energy accelerating the ions at the ends of
the solonoid's plasma core which would hopefully then be
able to compress the remainder of the plasma prior to the main
fusion initiating laser pulse.

I also hadn't intended to imply that the photons would carry
enough mass to do much compression.

No I only hope the photons would carry enough energy to get
the job done. No mass involved except the mass of the ions.

OK?

Thanks for all the intelligent responces so far.

Steve Ivy