A theoretical model for a spontaneous magnetic field in intense laser plasma interaction

The experiment results on spontaneous magnetic fields given by Najmudin et al. [Phys. Rev. Lett. 87, 215004 (2001)] can be explained by the kinetic model proposed by the present authors [Phys. Plasmas 8, 312 (2001)]. The dependence of the peak spontaneous magnetic field on the laser intensity is discussed. It is found the ratio of the number of thermal electrons to the total number of electrons is an important parameter.