= Ambipolar damping
<Ambipolar damping> is attenuation of magnetic disturbances by friction between the magnetically coupled charged fluid and a neutral fluid. In a strongly collisional mixture, the fluids nearly move together, but their small relative <velocity> dissipates <energy>. With drag coefficient $\rho_i\mu_{in}=\rho_n\mu_{ni}$, the frictional <energy> loss is $-\rho_i\mu_{in}\int|\mathbf u_i-\mathbf u_n|^2dV$. Neglecting other dissipative processes does not remove this collisional loss.
Back to article page
