Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Tokamak redeemed (maybe)
Date: Apr 05, 4:55 pm
Poster: Pierce Nichols

On Apr 05, 4:55 pm, Pierce Nichols wrote:

I've been kicking around ideas for how to build a working break-even fusor in my head for a while, and I came up with a potentially interesting idea. And I will get around to explaining that title *g*.

I've long since come to the conclusion that no machine that depends primarily on grids for acceleration is ever going to make it to break-even. The collisional losses are just too high. So you have to create virtual electrodes somehow, probably by confining a population of electrons. It seems the best way to do this is using magnetic fields.

Confining electrons in a spherical configuration seems to me to be a bit tricky, and not necessarily the best approach. It is relatively easy to confine them in a tokamak configuration. And that's potentially the way out of our loss problems. First, the configuration is highly efficient at confining the electrons, minimizing the necessary magnet size and electron injector current. Second, grids are completely eliminated. Third, the magnetic field used to confine the main electron population can also be used to guide fast electrons around the edge of the chamber to ionize fuel ions in that region. It's potentially the route to break even.

All that said, what are the first steps? I see the first step as working on the electron confinement. One early possibility -- use a grid to establish a confined electron population and then squeeze it down by turning on the magnets. It lets you prove out the electron confinement, and even run short demos, but it's not really going anywhere b/c you can only pack so many electrons in at once. It's also easy at this stage to probe the voltage distrubution in the electron cloud.

Next step is to figure out how to inject electrons continously. Not sure of this yet -- will prolly take a bit of computer crunching to get the angles and energy profiles right.

Next step is to figure out how to ionize fuel, maybe with tangential electron flow.

Then maybe you can get rid of the grids entirely and start the real slog up to break-even.