Enhanced and reproducible neutron emission from a plasma focus with pre-ionization induced by depleted uranium (U²³⁸)

Abstract

The effect of pre-ionization induced by depleted uranium (92U238) around the insulator sleeve on the neutron emission of (1.8–3.3 kJ) plasma focus device is investigated by employing time resolved and time integrated neutron detectors. The maximum average neutron yield of 2.5 × 108 is recorded at 3.5 mbar without pre-ionization, which increases up to 3.85 × 108 with pre-ionization. It is found that the pre-ionization enhances neutron yield, about (50 ± 5)%, broadens the neutron emission pressure range and improves shot-to-shot reproducibility of plasma focus operation for neutron emission. The pinhole images of charged particles emitting zones indicate that the pre-ionization increases the high temperature plasma volume.