Resonance interaction of a strong monochromatic wave with excited ions in a magnetic field

A theoretical analysis is made of the influecne of a magnetic field on the gain of a monochromatic traveling-wave field in a medium composed of charged two-level particles (ions). An expression is obtained for the traveling-wave gain, allowing for the drift of ions and weak saturation. It is shown that the drift results in the asymmetry of the gain profile.