Heat flux instability in cometary and solar plasma

An electromagnetic microinstability, driven by the electron heat flux in cometary and solar plasmas, is shown to get saturated due to nonlinear processes related to resonance broadening. This instability can produce large effective collision frequency, which leads to the reduction in the heat flux. In a cometary plasma the heat flux gets reduced by a factor of 4.5, whereas in the solar plasma, at the top of the transition zone, it is reduced by a factor of 300. The instability can produce magnetic fields of the order of 0.1γ in cometary plasma and of 10-2 gauss in solar plasma