Peculiar Features of Plasma-Focus Discharges Within PF-360 Facility

Abstract

The paper reports on recent studies of plasma-focus (PF) discharge dynamics and fusion neutron emission, which were performed with the PF-360 device at the energy level of about 120 kJ and the maximum current of 1.85 MA. Using the high-speed multi-frame imaging system, the behavior of a current-sheath layer during the radial compression phase and of a plasma column during the pinch phase has been investigated. Dynamics of the pinch phase was studied in the visible radiation and soft X-rays simultaneously. Characteristics of the neutron emission from PF discharges, which were carried out with and without the use of planar D2O-ice target, were studied experimentally. In particular, the anisotropy coefficient, defined as a ratio of the fusion-neutron yield to that measured at 90° to the z-axis, i.e. Yn(θ)/Yn (90°), was investigated under different experimental conditions. Various structures of the time-resolved neutron signals were recorded and interpreted, e.g. as a result of a double pinch. Possible mechanisms of the fusion neutron production have also been discussed.