Generation of high magnetic fields in an atomic plasma by irradiation with a super-intense femtosecond laser pulse

Quasistatic magnetic fields have been derived for a plasma produced by the multiple barrier-suppression ionization of atoms of solid surfaces, or clusters produced by a super-intense femtosecond laser pulse. The cases of linear and circular polarizations are considered. It was found that the Weibel instability increment in the case of circular polarization is much larger than in the case of linear polarization. Above-barrier ionization and relativistic effects reduce the rate of increase compared to tunnelling ionization. Collisions of electrons with atomic ions and other electrons are taken into account. Electron-ion collisions stop the development of the Weibel instability due to the alignment of longitudinal and transverse velocities. Estimates of the Weibel maximum quasistatic magnetic field are given.