SPACE-RESOLVED AND TIME-RESOLVED KA ABSORPTION-SPECTROSCOPY OF A LASER-PRODUCED PLASMA

We have studied the space and time evolution of the dense part of a laser-produced plasma obtained on a target composed of a chlorinated plastic foil covered with a samarium layer. With point-projection K-alpha absorption spectroscopy we measured the optical depth and the electronic temperature of the radiatively heated plasma as a function of time and space. Radiative hydrocode simulations describe correctly the experimental results. The plasma zone radiatively heated at 50-80 eV by the laser-irradiated samarium soft x rays expands just after the laser maximum when the laser-induced pressure has decreased. The obtained dense plasma exhibits shallow density and temperature gradients and could be used for dense-plasma studies.