Fusion for Neutrons: A Realizable Fusion Neutron Source

For 60 years, fusion research has been focused on fusion for energy as the ultimate carbon-free solution to the world's energy problems. It is proving a worthy but difficult task. However, it is relatively easy to produce high-energy fusion neutrons. The many potential applications of a 14-MeV neutron source are outlined, and a range of existing designs for such a source, based on a D-T fuelled spherical tokamak (ST), are reviewed. It is shown that the problems of high build and operating costs can be eased by a small device super-compact fusion neutron source (SCFNS) of major radius ~ 0.5 m, which although operating at modest plasma performance can provide megawatt-level neutron output. This breakthrough is achieved via the effectiveness of beam-plasma fusion, which becomes dominant in these conditions. Such a device would provide a resolution of the uncertainties in fusion STs (such as start-up, ramp-up, and steady-state operation), be an effective neutron source for research, and be an ideal entry vehicle for development of more powerful neutron sources in the new objective of “fusion for neutrons.”