Electron Cyclotron Absorption of Microwaves with Small Propagation Angle in Dense Plasmas

We derive an approximate dispersion equation for slow waves with frequency near electron cyclotron frequency, propagating quasi-longitudinally in plasmas. This equation is studied both numerically and within the framework of perturbation theory. The obtained cyclotron-absorption coefficients do not have singularities in the limiting case of strictly longitudinal propagation and ensure correct transition to well-known expressions for the case of large propagation angles. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 8, pp. 641–647, August 2005.