Re: Can electric fields achieve greater than breakeven fusion efficiency

Hi Peter,

In principle, it should be quite possible. In fact, some current work involving electrostatic confinement is outlined at http://www.kronjaeger.com/hv/fusor/construction/, and at http://www.worldhistory.com/wiki/F/Farnsworth-Hirsch-Fusor.htm The principle currently in use is described nicely at http://users.rcn.com/zap.dnai/neutron.htm.

In general, the current design seems to rely upon using an electrical grid to generate a negative charge. That attracts positively-charged, ionized deuterium atoms inwards. Some of those are accelerated through the grid, and collide to fuse in the center. They have found that the efficiency is increased by shaping the electric field to be non-uniform, in such a way as to cause the formation of beams of deuterium ions that collide in the center.

Although the current devices are used as neutron generators, and not energy generators, the proponents seem to have high hopes that they may eventually be used as efficient power generators.

The method used is obviously more dynamic than the one which you are envisioning, in which a positively-charged deuterium plasma is contained by a uniform, positively-charged sphere. It probably has a number of advantages, in that your proposed method would require heating the plasma to very high temperatures, in order for the ions to interact. Maintaining the needed temperatures might lead to some very severe engineering difficulties. I doubt that these would be insurmountable, however, given that the same issues are faced in magnetic confinement fusion. The avoidance of high temperatures, however, helps them to use smaller devices, a crucial factor for the currently intended applications. Also, by accelerating all of the ions to very similar energies, the efficiency should be higher (by heating the plasma, only a few of the ions have the highest energies).

I can find no arguments as to why the electrostatic method is not used rather than tokamaks. Much of the history of fusion work, however, is based upon budgetary issues, as various agencies or companies decided against pursuing multiple options, or decided that the payoff for fusion research was too far in the future and dropped it altogether. The original Farnsworth/Hirsch fusor, for example was abandoned after ITT discontinued funding.