Effect of Plasma Shielding on the Fidelity of Magnetic Probe in a Plasma Focus Environment

摘要

This paper examines the fidelity of a dielectric, encapsulated magnetic probe in the adverse plasma environment encountered in plasma focus experiments. The ionization of the surface of the probe produces a conductive layer that tends to shield it from external magnetic fields. The solution of the wave equation is used to show the allowed regions of conductivity, sigma, and thickness, d, for the ionized layer. The results show that as d approaches the penetration depth, delta = ( omega mu sigma)/sup exp 1 / sub 2 /, severe attenuation and distortion results, rendering the probe useless. When d is much less than delta, we encounter attenuation only, which also may be too severe for use. Finally, an experiment is described, which allows the experimenter to determine the fidelity of the probe. (ERA citation 03:051566)