MEASUREMENTS AND LASER-WAVELENGTH DEPENDENCE OF MASS-ABLATION RATE AND ABLATION PRESSURE IN PLANAR LAYERED TARGETS

Layered-targets experiments at 1.06-mu-m laser light have been performed in order to measure mass-ablation rate m and ablation pressure P(a) as a function of absorbed laser flux I(a) and laser wavelength lambda-L at irradiances of 10(11)-4.5 x 10(12) W/cm2. The results can be put in the forms m(g/cm2-s) almost-equal-to 4.25 x 10(5)[I(a)(W/cm2)/10(14)]5/9(1-mu-m/lambda-L)4/9 and P(a)(Mbar) almost-equal-to 20[I(a)(W/cm2)/10(14)7/9(1-mu-m/lambda-L)2/9, which are consistent with the estimates obtained from a steady-state self-regulated model for plasma heating and with hydrodynamical simulations. Results show also a small lateral energy transport.