Characteristic features of the formation of a crater on the surface of a metal irradiated with repeated laser pulses

The formation of craters on the surfaces of a series of metals (In, Pb, Sn) by laser pulses was investigated. The pulses were repeated at a frequency of 5 - 50 kHz and their duration was similar to 0.1 mu s. A crater was form ed mainly by successive spilling out of the melt from the irradiated target zone, but the process had a series of characteristic features which depend ed on the direction of the action of the laser radiation on the target and also on the number and repetition rate of the laser pulses.