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: Voltage and Cross section
Date: Oct 04, 12:09 pm
Poster: Richard Hull

On Oct 04, 12:09 pm, Richard Hull wrote:

>I was looking at the cross section of Deuterium and it seems to me that if you could just go higher in voltage in a fusor IEC, the reaction rate would increase.


Yes, the probability of collision is strictly a function of voltage up to a point where the curve levels off, but the only thing that fuses are particles and the number of them is strictly a function of current, and current alone. The voltage is just a "potential for action" and not action. Current supplies a volume of particles. RH
>For what I gather the problem with fusors is that dielectric break down occurs at about 40-50Kv. It would be interesting to see if anyone could find a way to go higher in voltage than this.
>Pulsing is a simple solution but still steady state power would be interesting to explore.

Farnsworth's team achieved 145kv applied with a 3" grid in a 6" chamber!!! That's only 1.5" separation for the 145kv. I have photos of their large Universal Voltronics supply and the giant oil bath insulators and potential spheres on top of those tiny fusors. Inside the vacuum the central grid was supported by two special Linde sapphire rods. (Linde had just perfected the process back then and the rods cost a fortune.) Today, such rods are readily available as stock, off-the-shelf items for a couple of hundred clams.

The vacuum break down potential is a function of pressure and separation, of course. Needless to say that the Farnsworth team used a much more rarified vacuum in the Mark III.

DC Supplies up to 100kv are easily fashioned by the amateur from common components. Handling, insulating and shipping those potentials on earth and in air is another matter altogether. 30kv is about the most potential I would want to have any component, in air, exposed to.

Richard Hull