Experimental investigation of the interaction between laser radiation and an argon plasma

An investigation was made of the processes which accompanied the passage of high-power laser radiation (λ=1.06 μ ) through an argon plasma generated in a plasmatron. Interaction of a laser beam of over 10⁷ W/cm² power density with a plasma whose initial temperature was 9500 °K and in which the electron density was ~10¹⁶ cm^–3 produced a perturbed region whose expansion during the first 10 λsec was of detonation type and which changed subsequently to a slow-combustion regime maintained throughout the passage of the laser beam. The plasma temperature rose to 19000 °K in the perturbed region although the absorption of the laser radiation was less than the experimental error (κ_λ≤0.04 cm^–1).