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: Vacuum plasma windows and microwave accelerators
Date: Sep 20, 11:31 am
Poster: Jones Beene

On Sep 20, 11:31 am, Jones Beene wrote:

Thanks for posting this information at an opportune time. If true, this concept (vacuum plasma window) could portend some interesting fusion experiments and open up the field to some of us without the budget for precision vacuum systems.

However, the idea behind it is so obvious that I have trouble believing that someone didn't try and discard it 70 years ago. I have this photo from the Rad Lab at Cal (Berkeley) showing an early cyclotron firing a proton beam into the lab unimpeded. I had often wondered how the vacuum was able to be maintained inside the machine, but now wonder why - if a good plasma window is easily created, why didn't someone pick up on the possibilites back then?

Also, this brings to mind a Russian patent from the fifties? (Kapitza?) for an atmospheric pressure DT reactor that uses both electrostatic confinement and concentric spherical grids - somewhat like the Fusor but setup in a container at atmospheric pressure or thereabouts.

Perhaps a similar plasma window (more like a spherical window) can be maintained at higher pressures inside fusor itself if the right conditions are met, although I am sure you would have to engineer the grid power supply to be current limited, which is not too difficult.

Some time ago, I found a TWT on ebay (12 ghz) which has been sitting around in the closet - perhaps just waiting for use in such applicaion.

In thinking about ways that one can augment the modest neutron output of a fusor, it might even be possible to irradiate the D plasma with microwaves and also with uv simultaneously...