Sv. Garnov et al., CHARACTERISTICS OF PLASMA SCREENING IN ABLATION SHAPING OF DEEP CHANNELS BY HIGH-INTENSITY LASER-RADIATION, Quantum electronics, 28(1), 1998, pp. 42-45
Determination of the rates of laser ablation (etching) of various mate
rials by powerful (up to 10(14) W cm(-2)) pulsed radiation revealed a
considerable reduction in the etching efficiency during shaping of dee
p ablated channels. The optical characteristics of the resultant plasm
a-vapour plume were measured. These measurements and numerical estimat
es led to the suggestion of two possible physical mechanisms of additi
onal screening resulting from the interaction with the channel walls:
limitation of plasma expansion and an increase of its density because
of evaporation of the wall material by the radiation emitted from the
plasma plume.