MEASUREMENTS OF MASS ABLATION RATE OF LASER-IRRADIATED TARGET BY THE FACE-ON X-RAY BACKLIGHTING TECHNIQUE

We report a novel method to measure the value of mass ablation rate pe r unit surface (m(over dot))in laser-irradiated targets. The face-on x -ray backlighting technique was utilized for the measurement. Flat pol ystyrene foils were irradiated by the partially coherent light at the intensity of 0.7 or 1.4 x 10(14) W/cm(2). We observed the residual are al mass of the planar targets to deduce temporally resolved mass ablat ion rate. Observed mass ablation rates are well reproduced both by the steady-state ablation model and by one-dimensional simulation. (C) 19 98 American Institute of Physics. [S0034-6748(98)02111-X].