Temperature measurements in plasmas produced by high-power lasers interacting with solid targets

Abstract

One of the main goals of the study of plasmas generated by short or ultrashort laser pulses is the estimation of a complex parameter as the evaluation of the plasma temperature. Considering the laser-target and laser-plasma interactions as nonequilibrium processes, it is not possible to define a unique plasma temperature because the behavior of the different subsystems such as ions, electrons, neutral particles, and photons is not uniformly correlated, and the physical parameters can be different in different values of the plasma plume. In this work different experimental setups and techniques and different empirical and theoretical approaches are compared by using a Nd:YAG laser with an intensity of 1010W∕cm2 and an iodine laser with an intensity of 1015–1016W∕cm2. Time-of-flight measurements have been performed with an ion-energy analyzer and by using a number of Faraday cups in order to measure the velocity and the kinetic energy of ions and electrons emitted by the plasma. The obtained results have been relevant to confirm that by using a Nd:YAG laser the plasma ion temperature in the plasma core is about 400eV. The electron emission indicates the presence of hot electrons with an energy of about 1keV. These results will be compared with the ones obtained with the powerful iodine laser at Prague Asterix Laser System.