Spatial localization of multicharged ions in a shock wave accompanying the interaction of CO2 laser radiation with a solid target in a low-pressure gas

An investigation was made of the near-ultraviolet part of the spectrum of radiation from a plasma created by irradiating a solid target in a low-pressure gas (0.5–15 Torr) with CO₂ laser radiation of intensity up to 0.1 TW/cm². During excitation of a buffer gas by a shock wave, spatially selective emission of individual spectral lines with excitation energies of 35–60 eV was observed. The radiation formed a hemispherical halo of radius which was a function of the intensity of the laser heating radiation and of the buffer gas pressure. The halo was due to spatial localization of the ions with the highest charge multiplicity generated in a shock wave excited in the gas near the target heated by laser radiation.