Hot electron generation in laser cluster plasma

A new mechanism is proposed that leads to an efficient hot electron generation in a laser cluster plasma. The mechanism is similar to the usual induced inverse bremsstrahlung. Under the action of the laser field, electrons are escaped from the clusters, then they scatter on the positively charged ionized clusters and gain energy. An analytical expression has been obtained for the transfer cross section at the elastic scattering of free electrons on the ionized clusters. This expression is exploited to calculate electron energy absorption by the electrons during the laser pulse. It was found that the inelastic scattering is negligible. Examples are considered for heating of electrons ejected from Xe clusters irradiated by a 50 fs laser pulse with a peak intensity of 10(18) W/cm(2). Expansion of clusters is derived within the frame of the Coulomb explosion model. The decrease of the cluster expansion has been taken into account because of the surrounding cloud of free escaped electrons. (C) 2003 American Institute of Physics.