Helium-3 Functions in Tokamak-Pumped Laser Systems

Helium-3 placed in an annular cell or array of cells around a tokamak fusion generator can convert moderated fusion neutrons to energetic ions by the ³He(n, p)T reaction and thereby excite gaseous lasants mixed with the ³He while simultaneously breeding tritium. The required ³He inventory is ∼ 5 kg for large tokamak devices. Special configurations of toroidal field magnets, neutron moderators, and reflectors must be incorporated to maximize the neutron flux in the laser cell. The annular laser radiation can be coupled to an unstable resonator at the top of the tokamak and extracted as a single output beam.