Development and performance characterization of a compact plasma focus based portable fast neutron generator

The design details and performance characterization results of a newly developed plasma focus based compact and portable system (0.5 m × 0.5 m × 1.2 m, weighing ≈100 kg) that produces an average neutron yield of ~2 × 10⁸ neutrons/shot (of fast D-D neutrons with typical energy ~2.45 MeV) at ~1.8 kJ energy discharge are reported. From the detailed analysis of the experimental characterization and simulation results of this system, it has been conclusively revealed that specifically in plasma focus devices with larger static inductance: (i) pinch current is a reliable and more valid neutron yield scaling parameter than peak current, (ii) the ratio of pinch/peak current improves as static inductance of the system reduces, (iii) the benign role of the higher static/pinch inductance ratio enables the supply of inductively stored energy in densely pinched plasma with a larger time constant and it is well depicted by the extended dip observed in the discharge current trace, (iv) there is the need to redefine existing index values of the pinch (Ipinch ^4.7) and peak (Ipeak ^3.9) currents in neutron yield scaling equations to higher values.