Theoretical and experimental studies of laser-produced plasmas driven by high-intensity femtosecond laser pulses

A theoretical and experimental study of the dynamics of the electron density gradient in near-solid-density plasmas produced by the interaction of ultra-short laser pulses with solid targets at intensities between 1013 and 1016 W/cm2 and pulse duration between 0.12 and 2.5 ps is presented. X-ray spectroscopy of n=3 to n=1 resonance and dielectronic satellite lines is used to determine the range of electron densities in the plasma. Frequency-domain interferometry is employed to measure the expansion velocity and the electron density gradient scale length as a function of laser pulse duration and intensity. Quantitative agreement is noticed with one-dimensional hydrodynamic simulations which include the solution of the wave equation for the laser field. copyright 1997 American Institute of Physics