Cyclotron resonance amplification of whistlers: a laser interpretation and analysis

The interaction of VLF whistler radiation with trapped (Van Allen) electrons is analyzed in terms of absorption and stimulated emission transitions at the Doppler-shifted cyclotron resonance. The transitions occur between energy states of the spiraling and high-energy electrons, and the deduction proceeds in the same manner as when the gain of a laser is computed. The result is substantially identical to that derived classically by solving the linearized Vlasov-Maxwell equations.