Spontaneous Transformation in the Pinched Column of the Plasma Focus

Abstract

The laser interferometry and X-ray diagnostic studies were performed within the PF-1000 facility operated with the maximum current of 2 MA and the deuterium gas filling (ensuring neutron yield above ). At this current, the plasmoidal, helical and toroidal structures were formed inside the plasma column. Some of them penetrated the column surface and later on were dissolved inside the dense plasma column. The period of their life was from a few tens to hundreds of nanoseconds and a plasma density was higher than in neighbor regions. It could be explained as a result of the plasma pinching by a magnetic field originating from the internal currents. Hard X-rays and fusion neutrons were produced during four different phases of plasma column transformations, i.e., in the period of the formation of a dense plasmoid, in the period of an escape of the plasma from the region between the dense structure and anode, during the interruption of the constriction, and during the integration of a “plasma lobule” with the pinch column. Fast electrons and deuterons were probably accelerated at the same region, during the same period of explosions of the plasma structures with a density ranging above . The plasma evolution could be explained by a spontaneous transformation of azimutal and poloidal components of magnetic fields. The poloidal component could be self-generated during the implosion of the current sheath.