Neutron Emission and Angular Distribution in Compact Plasma Focus Devices Operating at Hundreds of Joules

Measurement of anisotropy and neutron energy of the very small device PF‐400J (880 nF, 30 kV, 120 kA, 400 J, 300 ns time to peak current, dI/dt∼4×1011 A/s) are presented. Neutron emission with the device operating in deuterium has been obtained and the maximum total neutron yield measured is of the order of 106 per shot at 9mbar. The following diagnostics have been applied: time of flight (TOF) to estimate the neutron mean energy, and angular distribution of the neutron emission using CR‐39 nuclear track detectors covered with polyethylene located at several positions (between −90° to 90°). Discharges were performed at different pressures, 5–12 mbar, with a charging voltage of 30±2 KV (∼400J). With the results of the TOF measurements a mean neutron energy of (2.4±0.4) MeV was obtained. The angular measurements are compared with the total neutron yield (integral of the angular measurements). The results are consistent with an angular uniform plateau (isotropic emission) plus a shape peaked in the direction...