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 23, 1:12 am
Poster: Pierce Nichols

On Dec 23, 1:12 am, Pierce Nichols wrote:

>One should never be surprised at the prices of pro-vacuum gear and fittings. Just think what would be a reasonable figure and then go and order of magnitude higher. Fusor V will be a 10" model and the 2 conflat rings are going to be about $600.00. I will use only conflats. RH

Yeah, it's pretty outrageous. How much did the halves of the sphere run you? Also, what kind of power feedthrough are you using, and what voltage is it rated for? I looked at the specs for a 60 kV model and noted that it needs a 6" flange, which translates to a nipple diameter of 4" (!!!!). Do you know if there is a reliable and physically smaller way to get tht kind of voltage into the fusor?

> Yep. The diffusion pump is now a poor man's toy. Few pros will accept them in a system anymore and few in their right professional mind will spec them for any serious new installation. There is a glut of old pumps on the market just now and the prices are going to drop even more. Still, few amateur scientists except vacuum enthusiasts play with then. RH

COOL!! This means that us amateurs can attack the problem much more heavy-duty gear.
Question: if you are running a diffusion pump with an LN2 trap, is something like a micromaze a worthwhile investment, if the target vacuum is around the 10^-6 range? Do you know any surplus places that carry LN2 traps? Is one even necessary for the 10^-6 torr range? The Varian site quotes an ultimate pressure, untrapped, of 10^-8 for its small HS-2 pumps.

>All this is quite true and a calm hand with a sense of the pitch and roll of the glow discharge ship is needed. Captaining such a vessel is a learned art.

Slow experimentation is the way to get to where you are going :).