Emission of poloidal magnetic flux from a dense plasma focus

Abstract

A recent comprehensive review paper has summarized the current experimental state of knowledge on the question of existence of a poloidal component of magnetic field in the dense plasma focus and indirect evidence indicating its prominent role in neuron emission. This Letter looks at the role of the plasma as a curved, azimuthally continuous conductor moving in a small but nonzero geomagnetic field with a component along the device axis. The motional electric field then has an azimuthal component arising from the radial velocity, outward-directed near the cathode throughout the discharge, and inward directed in the radial implosion phase near the anode. This would drive an azimuthal current in the plasma. The electromechanical work done against the associated magnetic force density converts the kinetic energy into the associated magnetic energy density. This would act as a source of poloidal magnetic flux emission from a dense plasma focus, which has been experimentally demonstrated recently.