Expanding Operational Space in Inertial Electrostatic Confinement D-D Neutron Generators

The University of Wisconsin–Madison inertial electrostatic confinement fusion device HOMER was used to perform current scans at low and moderate pressures, 0.3 and 1.0 mTorr of deuterium, in which the cathode voltage, current, and pressure were carefully controlled. The data was taken in short intervals to avoid the degrading effect of chamber heating on the fusion rate. Low pressure operation should harden the deuterium energy spectrum, but the low pressure also reduces target density. The results showed the fusion rates for 0.3 mTorr are about half that at 1 mTorr. Also, the 6 low pressure current scans had confirmed the approximately linear neutron production rates with respect to current. All 6 of the 1 mTorr current scans showed trends of slightly above linear neutron rates. Also, a new IEC steady state D-D neutron production record of 2.5 × 10⁸ n/s was set at 150 kV, 100 mA, and 1.0 mTorr.