A compact, RF-driven, pulsed ion source for intense neutron generation

Lawrence Berkeley National Laboratory is currently developing a compact, sealed-accelerator-tube neutron generator for activation analysis applications. This portable generator is projected to produce a neutron flux in the range of 10⁹ to 10¹⁰ D-T neutrons per second. A 2 MHz radio-frequency (RF)-driven ion sources, designed to fit within a ~5 cm diameter borehole, is used. Typical operating parameters include repetition rates up to 100 pps, with pulse widths between 10 and 80 μs and source pressures as low as 4 mTorr. In this configuration, peak extractable hydrogen current exceeding 35 mA from a 2 mm diameter aperture, together with H₁⁺ yields over 94% have been achieved. The required RF impedance matching network has been successfully miniaturized to ~5 cm diameter and tested. Given the low duty cycle operation, the ion source and matching do not require any cooling