Energetic and angular characteristics of the reacting deuterons in a plasma focus

A model for the angular distribution of the neutron emission is derived and parametrized. This enables us to apply fitting procedures to the experimental data of the anisotropy of the neutron fluence, which furnish the mean energy and angular characteristics of the reacting deuterons. To this end the angular distributions of the neutron fluence were measured with high accuracy, on every shot the relative statistical errors being below 3-4%. At the same time, based on direct measurements of axially emitted ion energy spectra, we found a realistic distribution function for the reacting deuterons and an analytical expression for the anisotropy of the neutron fluence. The most important result provided by this method applied on a low energy plasma focus device is that medium-energy deuterons (50-100 keV) with a relatively broad angular distribution are responsible for most of the neutron yield.