Anisotropic electron heating by high frequency radiation and magnetic field amplification

We investigate the linear stage of development of the Weibel instability or iginated by anisotropic heating resulting from inverse bremsstrahlung of pl asma electrons colliding with ions in the presence of a high frequency radi ation field. We demonstrate that it is possible to amplify by several order s of magnitude quasistationary magnetic fields in plasmas interacting with linearly polarized field. The effect takes place both in weak and strong fi elds. We found that electron-ion collisions have a very significant influen ce on the growth rate of Weibel instability and on the degree of amplificat ion of the magnetic field.