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: EXL machines with magnetized grids
Date: Jun 26, 10:11 pm
Poster: Pierce Nichols

On Jun 26, 10:11 pm, Pierce Nichols wrote:

>> I was conceiving of wrapping solenoids around the grid elements. If you use an isolated floating supply and standard magnet wire, you don't even need insulation. This would result in field lines perp to the grid elements, deflecting electrons away from them and increasing electron lifetime dramatically.
>Tom Ligon, Bussard's systems engineer, and I are good friends, as most of you know. We discussed this idea and bit and realized it is likely to be a rather expensive project and not what the lower budget amateurs might find doable.

I'm aware that it will be more expensive -- at least 2-3 times more electronics and HV equiptment. And a whole lot more of a PIA, b/c you have to wind those solenoids. I do not look forward to that.

>Still, if it interests you, you should give it a try. Let us know as you go along in the effort how you are fairing.

Still working on design, but here are a couple of conclusions that I've come to:

1. The primary figure of merit is the electron confinement time. Most of the energy input to an EXL machine is creating and maintaining the electron cloud. The point of the solenoids is to boost this time.

2. Efficient plasma sources for creating the ions are probably necessary to actually reach break even. Conventional neutral gas injection, as most of the fusor experiments I have found open info for use, are probably not going to result in enough ions falling through the full accelerating potential to make up for the cost to create the ionizing electrons. A number of posts here have noted this problem with IXL fusors. I suspect it is even more problematic with EXL machines.

3. Ultra-high vacuum is probably a pre-requisite for break-even. The electron MFP wants to be very high to lengthen the confinement time. This also makes plasma sources more necessary.