Dense-plasma spheromak in plasma focus experiments

Summary form only given, as follows. Experimental evidence is presented for the formation, formerly predicted, of a closed, spheromak-like magnetic configuration (SLMC) by the plasma-focus-self-transformed magnetic field. The SLMC formation is characterized by (1) self-consistent generation of a poloidal magnetic field (the dynamo effect); (2) strong filamentation of electric currents; (3) stimulating role of the enhanced propagation rate of the magnetic field along the anode, due to the Hall effect; (4) a magnetic field reconnection process leading to the formation of the SLMC as a closed configuration, appears to occur before the the current sheath converges on the axis; (5) in its final stage, the SLMC takes the form of a squeezed spheromak configuration compressed and forced away from the anode by the residual azimuthal magnetic field; (6) the power density in the combined Z-/spl part/ pinch at major axis of the SLMC exceeds, by several orders of magnitude, the peak power density in the experiments on the force-free flux-conserver-confined spheromak; (7) the SLMC exhibits a cyclical tendency to form, be repelled from the anode, and reform repeatedly. The results suggest a possibility of further concentrating the plasma power density by means of compressing the SLMC-trapped plasma by the residual magnetic field.