Instability of a radiating plasma with a current

A theory is derived for the effect of Joule heating and radiation on the long-wave Buneman instability under conditions typical of the plasma of the solar atmosphere. The threshold and growth rate of the instability are modified substantially even in the linear theory. Under thermal balance conditions, the thermal effects are characterized by a single dimensionless parameter (which is determined by the current velocity and thermal velocity of the electrons, the rate of electron-ion collisions, and the wavelength). In general, these effects play a destabilizing role.