Use of Faraday probing to estimate current distribution in wire array z pinches

Abstract

In order to understand the formation and dynamics of plasma in wire array z-pinch experiments, measurements of the distribution of current throughout the array are required. We present details of two Faraday probing diagnostics aimed at exploring the magnetic fields and hence distribution of current in an array. An imaging Faraday system utilizes a short laser pulse to make estimates of the current distribution in the precursor column formed on axis before implosion. In a second system, a rod of high Verdet constant glass is placed close to the wires of an array and the polarization of a cw laser passing through the rod is monitored to examine the variance of current with time.