Weibel instability due to inverse bremsstrahlung absorption

A new Weibel source due to the inverse bremsstrahlung absorption is presented. It has been shown that in homogeneous plasmas, this mechanism may drive strong collisionless Weibel modes with growth rates of order of γ∼[Formula Presented] [Formula Presented] and negligible group velocities. In the laser-produced plasmas, for short laser wavelengths ([Formula Presented]<1 μm) and high laser fluxes (I>[Formula Presented] W/[Formula Presented]), this Weibel source is most efficient as the ones due to the heat flux and the plasma expansion. The useful scaling law of the convective e-foldings, with respect to the laser and the plasma parameters, is also derived. © 1997 The American Physical Society.