Recoil impulse received by metal targets as a result of interaction with microsecond CO2 laser radiation

The first measurements were made of the recoil impulse J received by bismuth, lead, zinc, and aluminum targets in vacuum as a result of interaction with microsecond CO₂ laser pulses of I = 10⁸–10⁹ W/cm² intensity. The measurements were carried out under conditions of planar one-dimensional target damage. It was found that the specific recoil impulse J/E (E is the pulse radiation energy) was independent of the intensity I, which had been observed earlier only in the low intensity range (I ~ 10⁶–10⁷ W/cm²) and correspondingly low target temperatures. This suggested a need for developing a theory of steady-state "advanced" evaporation at high laser radiation intensities. Possible physical mechanisms of this process were considered.