A Twin-Wave Quadrature Interferometer for Diagnostics of Pulsed Processes in Hydrogen and Erosion Plasma

摘要

A two-wave interferometer is described that is based on 0.6328- and 3.3922-μm He-Ne lasers and allows separation of the contributions of free electrons and the neutral component in partially ionized plasma to the phase shift of a probing electromagnetic wave under conditions of possible vibrations of the facility's optical elements. Using the quadrature method for forming informative signals, phase shifts were measured in a wide range of fractions of an interference fringe to several fringes with a high homogeneous differential sensitivity. The interferometer was used to measure the dynamics of the linear election density of both an atmospheric-pressure erosion capillary discharge in air and plasma of a hydrogen target in experiments on deceleration of heavy ions in an ionized substance.