High Performance High Repetition Rate Miniature Plasma Focus Device: Record Time Averaged Neutron Yield at 200 J with Enhanced Reproducibility

Abstract

A high performance high repetition rate plasma focus device with significant time averaged neutron yield and greater shot to shot reproducibility could be a highly valuable neutron source for Homeland Security applications. The single module fast miniature plasma focus ‘FMPF-2’ (2.4 μF, 56 ± 3 nH, 89 kA @ 14.0 kV, T/4~575 ns) was upgraded to four module ‘FMPF-3’ (2.4 μF, 34 ± 2 nH, 103 kA @ 14.0 kV, T/4~458 ns) device. The time averaged neutron output of (1.4 ± 0.6) × 106 n/sec at 1 Hz operation was enhanced to the record value of (1.4 ± 0.2) × 107 n/sec at 10 Hz operation for the burst length of 50 consecutive shots for deuterium filling gas pressure of 5.5 mbar in FMPF-3 device at storage energy of ~200 J. Other key findings of the investigation were: (i) the deuterium filling gas pressure for single shot and repetitive modes of device operation were needed to be optimized separately, and (ii) in the repetitive mode of operation the deuterium filling gas pressure was higher than that obtained for single shot mode and also yielded better reproducibility in neutron emission.