Laser-Based Polarimetry and Interferometry Measurements in a High-Temperature RFP Plasma

Summary form only given. Both the current density and electron current density are important parameters for fusion-oriented plasma research. In a reversed field pinch plasma, a far-infrared laser system is employed to measure both the Faraday rotation and electron density simultaneously with time response ~5 microseconds. This provides a single-shot capability for constraining magnetic equilibrium reconstructions and determining the current density distribution. Fast time response combined with low phase noise also enables us to directly measure magnetic, current density and electron density fluctuations. The two-fluid Hall effect is identified and found to be significant during magnetic reconnection events. A new diagnostic is being developed which detects the relativistic phase shift (Fizeau effect) of a laser beam propagating through a moving plasma thereby providing a measure of the electron current density. These diagnostic techniques have direct application to ITER.