Oscillations in radiation spectrum of electron moving in spiral in transparent medium and vacuum

Using the improved Lorentz self-interaction method the spectral distribution of the radiation power for an electron moving in a spiral in transparent isotropic medium is investigated. By using the relativistic model the fine structure of the electromagnetic radiation spectrum of the electron is obtained as a function of the transversal component of its velocity (the component perpendicular to the magnetic induction vector). The overlapping between neighbouring harmonics as well as oscillations in the spectral distribution of the electron radiation power are studied for the case when the transversal component of electron velocity is higher than the light phase velocity in medium but still less than the light velocity in vacuum. The fine structure of the radiation spectrum of the electron moving at a velocity higher than the light velocity in vacuum (superluminal velocity) is studied using the Sommerfeld approach. At the first harmonic the total radiation power of the electron in dependence on magnitude of transversal component of the velocity is obtained by means of the relativistic model and Sommerfeld approach.