Fusion-Fission Hybrid Using a D-D Cylindrical Inertial Electrostatic Confinement (IEC) Driver

Abstract

Recent progress in fusion development combined with the rebirth of nuclear fission power has regenerated interest in fusion-fission hybrid reactors. Such systems could be applied to both low power research reactors for use in University and industrial research assemblies and power reactors. However most attention has been directed at D-T fusion drivers using Tokamak, ICF or various alternate confinement systems like FRCs. However, the necessity to have large devices and breed tritium in the blanket complicates the concept. Here we propose the inertial electrostatic confinement (IEC) fusion approach since it offers the advantages of simple structural, high power density and a non-Maxwellian beam dominated plasma suited for burning advanced fuels to minimize tritium involvement. The cylindrical IEC allows a small compact unit which can be inserted into fuel element slots in the fission reactor core, thus providing a compact overall system and excellent neutronic coupling. The basic physics for the IEC has been demonstrated in small-scale laboratory experiments close to levels needed for driving a subcritical assembly for use in student teaching labs. However, for use in future high power hybrids significant scale-up in source strength is required. Scale up using an external ion source (e.g. a Helicon) so the background gas pressure is minimized in the reaction zone potentially offers a route to the required neutron source strength.