Study of the hydrodynamics of plasmas produced by laser irradiation of thin foil targets

The one-dimensional hydrodynamic expansion of plasmas produced by laser bea ms focused on thin foil targets is studied by using a self-similar approach . This work is an extension of the London and Rosen model proposed in the c ontext of x-ray laser studies. Here, cases with non-flat-top laser pulses a re considered and, for some of these, an exact analytic solution is deduced . The model is useful to study long scale length plasmas, produced by uniform laser irradiation, which become fully underdense during the laser pulse. I t predicts the fundamental plasma variables (scale lengths, density, temper ature) as a function of the experimental parameters (laser intensity, wavel ength and pulse duration, target thickness and composition).