First exploratory survey of poloidal magnetic flux emission from a dense plasma focus

Abstract

Studies of neutron emission from a dense plasma focus suggest that a significant fraction of neutron emission in some shots is caused by fast deuterons that have a prominent azimuthal component of motion. Recent examples are observations of long-lasting neutron emission in the side-on direction in PF-1000 and of neutron flux asymmetry (end/side) less than unity in Gemini. Such azimuthal motion of deuterons indicates the presence of an azimuthal electric field that accelerates them and a poloidal magnetic field that keeps them within the zone of acceleration. This in turn must be accompanied by poloidal magnetic flux emission (PMFE) from the plasma focus. Recently, a diagnostic technique for detection of PMFE has been proposed and demonstrated. This paper presents results of its successful replication and the first ever exploratory survey of PMFE emission using the UNU-ICTP plasma focus at the Nanyang Technological University, Singapore.