Particle-in-cell simulations of laser-produced hot spot

Summary form only given, as follows. An electrostatic hybrid particle-in-cell (PIC) code has been developed to model transport processes in a laser-produced hot spot. It includes electron-electron and electron-ion collisions, inverse bremsstrahlung heating in Langdon form, and a self-consistent ambipolar electric field defined by the quasi-neutrality condition. Having the advantage of averaging over the laser frequency and Debye length this PIC code is an effective tool for investigation of a localized plasma heating by spatial inhomogeneities of a laser beam. The simulations have been performed to study the long time evolution of the hot spot heated by the continuous laser pump. The electron distribution function is investigated inside and outside of the hot spot. Particularly the possibility of occurring return current instability (RCI) is considered. The PIC simulation of ion dynamics on the ion acoustic time scale are performed and dispersion relations for plasmas with temperature gradients that can lead to RCI are presented.