The Weibel instability on strongly magnetized microwave produced plasma

The electron distribution function (EDF) of plasma generated due to the interaction between a circularly polarized intense microwave (MW) field with a dilute gas is investigated in the presence of a static magnetic field. Making use of the EDF, the electron dielectric permittivity tensor is obtained. Taking into account the anisotropic structure of EDF, it is evident that the Weibel instability can occur in such plasmas. Therefore, using the adiabatic approximation, the dispersion relation is obtained for small electron perturbations across the MW field. By solving the dispersion relation, it is shown that not only does the magnetic field decrease the growth rate of the Weibel instability, but that a sufficiently strong magnetic field can make the instability completely disappear. (c) 2006 American Institute of Physics.