Dependence of the temperature of stochastically heated electrons on the flux density of pulsed laser radiation on a target

Electron dynamics in the field of focused picosecond multimode laser radiation was considered by numerical methods. It was found that the electron energy during stochastic perturbation of its trajectory can exceed the energy of oscillatory motion in a plane wave by several orders of magnitude. The electron distribution function was studied based on 2D numerical simulation. An analytical expression for the distribution function of relativistic electrons as ideal gas was derived. The distribution function in the radiation flux density range of 1014–1017 W/cm2 was compared with an analytical expression of the equilibrium distribution; a temperature characteristic for electrons stochastically heated by the laser field was introduced. The dependence of the electron temperature on the radiation flux density was determined.