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: Fusor Operation - a general question
Date: Jul 03, 0:53 am
Poster: Dave Cooper

On Jul 03, 0:53 am, Dave Cooper wrote:

Been thinking about the operating problems recently discussed here....grid losses and gas collisions, to name just two, and it occurs to me that perhaps....the fusor is best operated on a "once through" ion collision basis.. rather than on a recirculating ion basis.

The experts here, please feel free to jump in and correct my misunderstandings. It seems that one of the main strategies of Farnsworth's Fusor is the recirculation of ions to create "virtual" anode and cathode structures (otherwise known as concentrations of ions), the latter of which is where the fusion occurs.

But... the grids needed to establish these spherical potential shells actually become an energy sink, since they are not and cannot be 100% transparent.

However, if the ion guns are built to produce very well focussed beams and aligned to illuminate a small central reaction zone, then the non reacting ions will simply exit from this zone, and decelerate toward the outer grounded fusor shell.

The reacting ions will produce the neutrons and contribute to additional kinetic energy of the surrounding gas ions.

By setting the ion guns radially inward from the ground shell and operating them at a modest negative bias from ground, the unreacted D+ ions upon returning to the outer shell region become neutralized by collision with either Fusor walls or a ground potential electrode screen, at quite low velocities (and therefore nearly zero energy). They can be gathered up (i.e.: pumped) for reinjection at the nearest ion gun.

Electron guns for SEMs can produce nm size spots, indeed the useful spot diameter is usually partly limited by the enerergy the surface can absorb without deformation. Ion guns should be capable of similar focus.

May be this is what is normally done... and I just missed the point. Comments please.

Dave Cooper