Detection of poloidal magnetic flux emission from a plasma focus

Abstract

Direct experimental evidence for the existence of axial magnetic field both in the radial implosion phase and the pinch phase of a plasma focus has raised many questions of fundamental importance. The most fundamental of these is the fact of its existence, which is incomprehensible in terms of a conventional view of plasma physics. The plasma is known to have an axis of symmetry in the radial implosion phase. The axial magnetic field has a defined polarity with respect to the axis. Since the equations of magnetohydrodynamics are unchanged by flipping the sign of the axial coordinate, the polarity of the axial magnetic field must arise from the initial conditions. Exactly how the initial conditions determine the polarity of the axial magnetic field is not clear. More data are needed to guide theoretical developments of this question. There are several technical problems with the conventional techniques of axial magnetic field measurement such as magnetic probes and Faraday rotation measurement. The combined effect of theoretical and experimental difficulties is that researchers avoid research related to the axial magnetic field in axisymmetric plasmas in favour of more result-oriented projects, with the unfortunate consequence that questions related to the presence of axial magnetic field in axially symmetric plasmas remain unresolved. In order to promote research related to the questions related to the axial magnetic field in the plasma focus and other plasmas with an axial symmetry, this paper introduces a new technique that skirts the technical difficulties of measurement by redefining the objectives and scope of measurement. The paper is written in a tutorial format for the benefit of young researchers just beginning their research career and hence will not be published in regular journals. Peer scientists and young researchers are encouraged to contact the author directly.