Role of the Bernstein modes in the electron cyclotron second-harmonic wave absorption

The propagation and absorption of perpendicular second-harmonic electron cyclotron waves in a plasma slab are studied by means of propagation equations directly deduced from the Vlasov–Maxwell system. An electromagnetic wave injected from the vacuum into the plasma can be transformed into a quasielectrostatic forward mode, which, in turn, is converted into a Bernstein backward wave. The occurrence of this double-conversion process and the global absorption and reflection are analyzed and the dependence of the phenomena on the plasma parameters and wave characteristics is investigated.