Thermal model of pulsed laser ablation under the conditions of formation and heating of a radiation-absorbing plasma

A model is proposed for the description of the dynamics of the absorption of radiation by a plasma formed on evaporation of a solid material by nanosecond laser pulses of moderate intensity when a thermal ablation regime is established. The model takes into account the nonisothermal nature of the plasma heated during a pulse as a consequence of the absorption of radiation and makes it possible to calculate the laser energy balance. Measurements were made of the vapourised mass and of the attenuation of radiation during laser ablation of graphite and a satisfactory agreement with the results of calculations was obtained.