Collision of a laser plasma flux with a ring-shaped obstacle and excitation of autoionizing states of ions in obliquely incident shock waves

The method of spectroscopy with temporal and spatial resolution was used in an investigation of the collision, with a ring-shaped obstacle, of a plasma created by interaction of laser radiation with a solid target. This collision excited autoionizing states of С II and С III ions. The velocities of ions with diiferent ionization multiplicities, as well as the electron density n_e and the electron temperature T_e were determined by an expanding plasma flux, and the density and temperature were also found for the case when the plasma collided with the obstacle. The kinetics of excitation of autoionizing states was determined when the pressure of a buffer gas in the vacuum chamber was varied. The spatial distributions of n_e and T_e were used to analyze the mechanism of excitation of the autoionizing states.