Magnetic field generation in a plasma in the presence of an ultrashort laser pulse

The description of the Weibel instability linear stage for a plasma interacting with an ultrashort laser pulse is given. Pulse durations both smaller and larger than the inverse collision frequency of the thermal electrons are considered. In the latter case the pulse duration is smaller than the thermal electron heating time. The growth rate of the instability is derived and the possibility of a considerable quasistationary magnetic field amplification demonstrated. (C) 2001 American Institute of Physics.