Second Generation Neutron Generator using a Ultra-compact HV Power Supply

In this work, we will improve on typical point-source neutron tubes and enhance the ionization process using a broad-area, cold electron source, as well as using large titanium (Ti) surfaces coated with deuterium or commercially available getter materials to provide for additional deuterium gas supply.  A ‘cold’ electron emitter simplifies the generator design and improves reliability by eliminating components and reducing the overall operating temperature.   The use of a novel electron emitter and deuterium ionizer design allows for increased deuterium ion generation and thus improved neutron production rates.  The neutron source geometry will be optimized for the footprint required for the small size and light weight, and the flux enhanced even further by using a broad-area ion beam instead of a tightly focused beam as is done in typical tubes.  These improvements will provide higher neutron flux than is currently available, using fewer components and generating less thermal stress. We will partner with Stanford University to develop a miniaturized high voltage power supply (HV PS)  for acceleration of the deuteriium ions (D+) to the  100 keV  for the creation of neutrons by the DT fusion reaction. Also required for the operation of the source: miniaturized, light-weight +1 to +2 kV power supplies able to extract the electrons from the emitter structure. The kinetic energy of the electrons needs to be reduced to approximately 100 eV since the ionization cross-section reaches a maximum at that energy. A third power supply is required to do this: -900 V to -1900 V, depending upon extraction power supply voltage. Small, lightweight circuits have been designed, built and tested by our subcontractor. Modest changes in some of the circuit ratings and performance specifications are required. The power supply circuits, electron emitters, deuterium gas handling, grids, and final neutron-production target need to work together in a configuration that allows application of the necessary potentials at required power levels. The entire assembly will be enclosed in a vacuum tight enclosure that can withstand the necessary heating, outgassing, cooling, loading with deuterium and tritium. Control circuitry for operator-controlled on/off, preparation for neutron emission, and cool-down following use. A weight and size budget will be part of the Phase 1 effort; parts for  the electron extraction, deuterium ionization, D+ ion acceleration and neutron production chamber, grids, connections, vacuum vessel will be analyzed and designed to minimize  weight and size.