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: Fusion reaction rates
Date: Dec 22, 9:58 am
Poster: Pierce Nichols

On Dec 22, 9:58 am, Pierce Nichols wrote:

>>This is something I think is a pretty serious problem. How much energy are we wasting this way?
>About 99.999999999% wasted! We are doing fusion though. RH

Which is of course the point . I want to go to the next step. It's a certain amount of native arrogance.

>Your idea is clever and has merit, but the 70s Hirsch-Meeks patent achieves the same result with less hardware. Single extra grid. Electrons shot out by a filament almost touching the shell race towards a grid real close to the shell ionizing the D2 gas to make deuterons which accelerate through the bulk of the potential drop to achieve fusion energy. RH

Ok, I guess I did not understand the Hirsch-Meeks patent as well as I thought I did. What is the bias on the first grid inside the shell? Is it positively biased? If it is, then I described pretty much the same thing, replacing the shell with a grid. Having the outer shell be a grid instead has the potential benefit for the scrounger of allowing the use of a variety of scrounged chambers. I just priced conflats of the appropriate size for the two halves of a spherical fusor and was unpleasantly surprised.

>It is, but we are doing MORE fusion. Wall outlet power is so cheap! Besides, few on this list will ever even do the ultra-simple fusor! For those micro few that do, my tips still hold. RH

Given! And I remain one of the many that hasn't bent any metal yet. And outlet power is cheap. However, going high w/o a better way to control current is just asking for trouble.

>Correct! again, but how many here will ever use the higher vacuum.... almost none; tighten up their ion optics..... ZERO; use higher voltages... a few. Doing fusion on th' cheap demands a simple fusor. You are talking orders of magnitude more bother, precision and mainly expense. Leaving virtually every other person on this list out of the ballpark. Let's get 'em demoing first (glowing), fusin' second, and refining third. RH

Higher vacuums, while difficult, are not totally impossible for the home experimenter. I've seen surplus diffusion pumps in the right size range for sale at surplus houses for a few hundred dollars. Try www.ptb-sales.com, which is a surplus house specializing in vacuum gear. Their cheapest diffusion pumps are less expensive than their cheapest mechanicals.

Improved ion optics, beyond restricting ion generation to the margins of the chamber, seem to me to give the lowest return on effort.

Higher voltage is prolly the easiest to achieve -- just add another stage or three in the voltage multiplier. Overcurrent becomes a real danger for most experimental fusors b/c of the negative dynamic resistance characteristics of glow discharges.