Magnetic field measurements on PF - 1000 and PF - 3 facilities: current sheath structure and neutron scaling

Study of the mechanisms for generation of neutron and X-ray emission in megajoule and submegajoule facilities is one of the priority directions in the development of plasma focus (PF) systems. Interest in these studies is motivated by the important problem of creating a high-power neutron source. The empirical scaling Yn ~ I4, where Yn is the neutron yield and I is the amplitude of the current pulse, reliably operates in the discharge energy range from several kilojoules (kJ) to a few hundred kilojoules. In order to further increase the neutron yield, it is necessary to carry out experiments on large facilities with currents of several megaamperes. At present, there are four PF facilities operating in this energy range: PF-3 at the Kurchatov Institute (Moscow, Russia), PF-1000 at the Institute of Plasma Physics and Laser Microfusion (IPPLM, Warsaw, Poland), KPF-4 “Phoenix” at SPTI (Sukhumi, Abkhazia), and the North Las Vegas Facility at the NSTec (Nevada, USA). This study is devoted to the comparative analysis of the magnetic field distribution, the dynamics and structure of the plasma current sheath (PCS), and the neutron yield scaling in two of the above facilities, PF-3 and PF-1000.