7A5 - Evaporation and heating of a substance due to laser radiation

Gas-dynamic equations are studied for determination of heating, vaporization, and expansion of substance when a radiation of -switched laser is collimated onto a surface of solids. A possibility of existence of the self-regulating regime of vaporization and heating in one-dimensional case is proved for the case when an optical density value of the vapored gas is about unity in all the stages of this process. The values for temperature and velocity of the substance expansion are obtained. An approximate consideration of this problem is carried out when a spherical case of expansion takes place describing substance vaporization by a strong-focused radiation. The experimental investigation data of gas dynamic values are presented for the case of "plume" arising from collimated laser radiation interactions with the energy of several hundred MeV. Results obtained in experiments permit to calculate temperature, expansion velocity, and optical transparency of vapored substance for different stages of this process.