HIGH-PERFORMANCE BEAM-PLASMA NEUTRON SOURCES FOR FUSION MATERIALS DEVELOPMENT

The design and performance of a relatively low-cost, plasma-based, 14-MeV deuterium-tritium neutron source for accelerated end-of-life testing of fusion reactor materials are described. An intense flux (up to 5 × 1018 n/m2·s) of 14-MeV neutrons is produced in a fully ionized high-density tritium target (ne ≈ 3 × 1021 m-3) by injecting a current of 150-keV deuterium atoms. The tritium plasma target and the energetic D+ density produced by D0 injection are confined in a ≤0.16-m-diam column by a linear magnet set, which provides magnetic fields up to 12 T. Energy deposited by transverse injection of neutral beams at the midpoint of the column is transported along the plasma column to the end regions. Three variations of the neutron source design are discussed, differing in the method of control of the energy transport. Emphasis is on the design in which the target plasma density is maintained in a region where electron thermal conduction along the column is the controlling energy-loss process.