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: Ion guns
Date: Jul 15, 10:33 am
Poster: Richard Hull

On Jul 15, 10:33 am, Richard Hull wrote:

>I was wondering does anyone know what the beam voltage or current were on the Farnsworth devices.
>I saw a previous post that said that the beams would burn through the vacuum chamber.
>That had to be some serious currents to do that right?

>Not Really. They used voltages on the order of 40kv and as high as 100kv with their D-D fusor efforts. Their beam currents were on the order of 30ma.

It must be remembered that 30 ma @ 60KV is 1800 watts. The deuteron beams were microscopically tiny, being focused beams. Farnsworth's outer shells were incredibly thin. In some cases as thin as .02inches. An 1800 watt focused spot of energy in say a 0.1" circle would vaporize SS quickly. This is partly due to the terrible thermal conductivity of the metal.

The simple fusor we use spreads the energy out over the entire outer shell.

Richard Hull