Study of a cumulative gas phenomenon in plasma focus discharge

A cumulative phenomenon of nitrogen gas at a pressure of 3.3 torr in a 1.2 kJ coaxial plasma focus discharge device was investigated experimentally. Variations of nitrogen gas density in the axial phase along the inter-electrode region were estimated experimentally from the plasma current sheath (PCS) dynamics in terms of its velocity, acceleration as well as axial magnetic force data. An inclination angle of PCS with the axial distance was estimated. Investigations of the ratios of radial and axial magnetic force as well as the magnetic pressures coupled to PCS were studied. The variation of the trapping fraction η with the axial distance was computed theoretically based on a snow-plow model and was compared with experimental results.