Fusion for neutrons: A realisable fusion neutron source

For 60 years fusion research has been focused on Fusion for Energy (F4E) 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 14MeV 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 and uncertainties in operating conditions, can be eased by a small device SCFNS (Super-Compact Fusion Neutron Source) of major radius ~0.5m, which although operating at modest plasma performance can provide megawatt-level neutron output. This break-through 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´ (F4N).