D-D neutron measurements on a 40-kV, 60-A neutral beam test facility

Neutron production rates from deuterium-deuterium (D-D) reactions are measured during deuterium beam operation on a 40-kV, 60-A prototype neutral beam line developed for fusion research. The neutral detection system consists of a 235U fission chamber, a 3He proportional counter, and thermoluminescent dosimeters (TLDs). Measured neutron yields were lower by a factor of 4 than theoretical values for steady-state, drive-in targets. Measured neutron intensities per unit ampere of beam current at 40 keV ranged between 4 x 108 and 7 x 108sec-1. Variation in neutron intensity is investigated as a function of beam energy (25 to 40 keV), beam current (30 to 60 A), and beam pulse length