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: thermionic cathode
Date: Nov 07, 5:55 pm
Poster: d.preston

On Nov 07, 5:55 pm, d.preston wrote:

>>wouldn't a fusor work better if the inner
>>tungsten or tantalum electrode was constructed as a themionic emitter.
>Actually, no!
> We seek to actually SUPRESS emission in this region! It never works, however, and that is why the simple form of fusor has severe limitations. A simple fusor, in runaway, actually has its current rise percipitously due to the electron emission of the white hot inner grid supplying the tons of electrons as current carriers. Fusion completely stops with this condition.
>Ideally, we want 100% of the electrons to be created at, and over, the entire inner surface of the outer spherical containment vessel or positive grounded electrode. This allows all of the ion production to occur far away from the inner negative electrode. This then allows the, so created, deuterons to fall through the full potential of the device before entering the reaction zone. This is the ultimate embodiment of the "velocity space" feature of the fusor. Thus, as I have posted before, we need the thermionic heater at the outer shell and biased accordingly as in the Hirsch-Meeks patent. (Fusor IV)
>Richard Hull

ok. next idea..

why not insulate the inner electrode.
ie. cvd coat the inner electrode with silicon dioxide or aluminum oxide.

the inner electrode will capacitively couple and the insulating layer will lower the electrodes emmission.