Energy losses of a charged particle due to excitation of helicons in plasma-like media

We study the energy lost by a particle moving along the helical line in a static magnetic field due to Vavilov–Čerenkov radiation of volume and surface helicons. It is found that the energy losses related to excitation of volume helicons are equivalent to the energy losses of a magnetic moment created due to the charge rotation. The magnetic moment moves at a constant velocity along the magnetic field. It is shown that collisionless damping of volume helicons in plasmas is based on the Čerenkov radiation of magnetic moment. Radiation of surface helicons by a particle does not correspond to the energy losses of a moving magnetic moment. This is related to the fact that not only magnetic (H) waves but also electric (E) waves contribute to the excitation of surface helicons, which leads to an increase in the energy losses of a particle. © 2004 Springer Science+Business Media, Inc.