Generation of currents and propagation of plasma fronts in the case of two-pulse interaction with a target in air

An investigation was made of the enhancement in the efficiency of generation of currents when a target in air was subjected to two consecutive CO₂ laser radiation pulses. Preliminary interaction with a low-energy (1.5–5 J) pulse increased by more than one order of magnitude the currents generated by the second pulse and this was true in a wide range of energies of the latter pulse. The energy conversion efficiency was practically unaifected. The results were in qualitative agreement with the proposed pattern of plasma formation and propagation of shock waves near a target.