Geometrically and Reflectively Enhanced Embedded Fusion

Inertial Electrostatic Confinement (IEC) fusion is a technique that uses electrostatic fields to confine and heat ions in order to achieve nuclear fusion. This is achieved by using a metal grid as the cathode to create the confining electrostatic well. There have been unpublished suggestions that the materials and geometry of the cathode have an effect on the fusion rate. A systematic experimental study is carried out on a range of non-standard cathode geometries and materials in an IEC fusion device under low energy conditions to challenge the commonly accepted notion that a more highly transparent grid is the most efficient means of fusion neutron production. A number of hollow cathode geometries were exposed to a range of different pressures, voltages, and currents, which were compared to an IEC grid under the same conditions. The cathode surface temperature and ion energy distribution in the plasma were used to correlate the fusion rate associated with the temperature and plasma properties. It was found that the hollow cathodes operating under the abnormal discharge conditions produced more neutrons than an IEC grid. A model using ambipolar diffusion and sheath terms was developed. A study into the material dependence of the cathodes was performed using stainless steel as the control group. Graphite was found to produce an order of magnitude more neutrons than stainless steel. A model was presented that showed a qualitative trend for all metallic samples that correlated with the experimental results. However the anomalous results from graphite proved to be more elusive. Finally, a cathode that combined both the most efficient geometry and material was studied. The graphite biconical cathode was found to have a higher fusion rate than the sum of its parts. This study represents the first of its kind focusing on the effects of material and cathode geometry under low energy discharge conditions on the neutron production rate