Current disruption and electric field in dense plasma focus*

Plasma Physics Division at NRL is running a Dense Plasma Focus (DPF) experiment on the HAWK pulsed power generator (640 kV, 665 kA peak current). This experiment and many similar devices in the past produced neutron yields orders of magnitude above the thermal neutron yield suggesting that some mechanisms accelerate ions to energies well above thermal energy. We modeled the experiment using MHD code Athena coupled to an equivalent circuit model for HAWK and confirmed that the thermal yield is indeed much smaller than the observed yields. In addition we modeled particles accelerated in the motional vxB fields with the code Hephaestus and confirmed that this acceleration can only give particles with energies up to 0.2 MeV. To study potential non-MHD mechanisms of acceleration we introduced physically motivated, but artificial current disruption and calculated resulting electric and magnetic fields. We will report on the morphology and the energy spectrum of the neutron source described by such model.