Polarimetry–Interferometry Diagnostic for Measurement of Magnetic and Density Perturbations in the High-Temperature Plasma Core

Diagnostic techniques to measure the internal structure of density and magnetic perturbations, both equilibrium and turbulent, are becoming increasingly important for assessing the confinement properties of high-temperature magnetically confined fusion plasmas. Recent advances in laser-based polarimetry-interferometry techniques now permit simultaneous measurements of both density and magnetic field with fast time response and high phase resolution. Images of intrinsic tearing instabilities driven by radial gradients in the parallel current density are shown for the combined measurements.