Plasma electron kinetics in a weak high-frequency field and magnetic fieldamplification - art. no. 046408

We describe the linear stage of Weibel instability in a plasma heated via i nverse bremsstrahlung absorption of a high-frequency, moderate intensity ra diation field under conditions in which the plasma electron velocity distri bution function is weakly anisotropic. We report on the possibility of a si gnificant. amplification of spontaneous magnetic fields both in the case of an electron distribution function slightly departing from a Maxwellian in the region of subthermal velocities, and in the case where the Langdon none quilibrium distribution is formed. We show that the direct influence of col lisions on the Weibel instability growth rate may be traced back to subther mal electrons, for which the effective collision frequency is large.