PPPS-2013: Fast framing camera images of neutron production cessation at high currents in a Dense Plasma Focus machine

Summary form only given. Imaging studies are being performed to investigate the formation, propagation and pinch point characteristics for a plasma sheet in the Dense Plasma Focus (DPF) device in Las Vegas. Deuterium is used as a working gas with r-Z pinch heating and compression at the pinch point resulting in fusion of the deuterium and the production of 2.45 MeV neutrons in a very short and intense burst of 20-50ns. During this fusion process of deuterium gas we have observed yield cessation as 1x1012 neutrons per pinch is reached. While the DPF has a maximum stored energy of 2 MJ, the production of neutrons ceases as current exceeds 3 MA. It is anticipated that images of this process will show why fusion ceases at high currents. Images of the plasma formation, movement and pinch at varying currents and phases including rundown and the pinch sequence will be discussed. Images are acquired using an ultrafast framing camera system through a large window (30" x 12") that has been installed on the vacuum chamber tube surrounding the anode/cathode of the DPF. These images are used to verify magneto-hydrodynamic (MHD) simulations and better understand why neutron yield ceases at high current with current designs. Neutron yield, current and corresponding fast framing camera images for several phases (axial run down, z-compression and pinch) of the neutron production process will be presented and discussed.