Comparison of measured and calculated x-ray and hot-electron production inshort-pulse laser-solid interactions at moderate intensities

Ultrashort pulse laser-solid interaction experiments with 4X10(16) W/cm(2), 120 fs, 45 degrees incidence angle p-polarized pulses are theoretically an alyzed with the help of 1 1/2-dimensional (1 1/2 D) particle-in-cell (PIC) simulations. The laser impinges upon preformed plasmas with a precisely con trolled density-gradient scale-length. PIC electron distribution functions are used as an input to 3D Monte Carlo simulations to interpret measured el ectron distributions and K alpha radiation emission. Satisfactory agreement between the experimental and simulation results is obtained for the measur ed absorption coefficient, the energy distribution of the back-scattered ho t electrons, the hot-electron temperature in the bulk of the target, and th e K alpha yield, when the preplasma scale-length is varied. [S1063-651X(99) 00108-7].