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: Re: Where can I get an ion gun???
Date: Jul 16, 2:22 pm
Poster: Mark Sloan

On Jul 16, 2:22 pm, Mark Sloan wrote:

So what you would like to do is get the advantages of ion guns but cheap and easy.

The advantages of ion guns seem to be 1) they can be focused to hit the center (and miss the inner grid wires), 2) ions can be at full, applied voltage. This is in comparison to the simple fusor where focusing still seems to happen, but inner grid impingement also happens and perhaps worse, the ions may be generated anywhere in the sphere. Since their maximum energy when they hit the center is determined by how close to the inner or outer grids they form, they on average will impact the center with perhaps the applied voltage. (Average could be less if most of the ions are generated close to the center negative grid.)

IF you can form the ions predominately at the outer + positive grid by some other means than an ion gun, I think you will have most of the advantages of an ion guns at much lower cost. That is, the spherical shape should automatically focus the ions in the center. Further, the majority of the ions could impact the center with full-applied voltage.

One way to generate ions at the outer shell might be just sharp ended projections on the inner side (see postings on "Small wire brush deuterium ion generators?" June 28th below). (If small and sharp enough, these projections may generate strong enough local voltage gradients to tear lose an electron and form an ion, but I have never seen any references demonstrating this in the literature.)

Someone can probably also think of a way to generate some electron flows from heated filaments near the outer shell, accelerate the electrons and then they will generate ions locally.