Numerical simulation of Čerenkov whistler emission by a modulated beam

Through Cerenkov emission, the interaction of an electron beam with a plasma leads to the excitation of whistler waves. Particle‐in‐cell simulations show that, when the beam is injected at an angle with respect to the magnetic field, the whistler wave emission of a modulated beam is increased compared to the same beam without modulation. This increased emission is related to the transfer of energy which occurs between the electrostatic mode directly excited by the density modulation and the electromagnetic whistler. This transfer of energy requires that the electrostatic field has a component perpendicular to the magnetic field.