Effects of collisions and particle trapping on collisionless heating

Collisionless power dissipation has been calculated analytically taking into account particle trapping in the wave and electron collisions with neutrals. The approximation of analytical calculations for a decrement of nonlinear Landau damping gives, within an error less than 5%γn1=γ_ltanh(2υT_τ where γ_l is the linear Landau damping, υ is the total collision frequency, and T_τ is a bounce time of trapped electrons. The theory is applied to the calculation of collisionless heating in a bounded low-pressure glow discharge plasma. It is shown that the difference with previously published results of linear theory on collisionless power dissipation can be as large as 3 orders of magnitude.