Numerical simulation of electron cyclotron resonance phenomenon using an axisymmetric transverse electric field

Abstract

Abstract As a contribution to the study of the resonant interaction between of an electron and the transverse electric field of a stationary electromagnetic wave in the presence of a static homogeneous magnetic field in this work we develop a numerical study of the acceleration of electrons by cylindrical mode TE011. In order to get a better understanding of the particle-wave interaction, the electric field of the microwave mode is decompose as the superposition of a left-and a right-hand circularly polarized standing wave because electrons interact effectively only with right-handed circular polarized wave. The trajectory, energy and phase-shift between the electron transverse velocity and the electric field are determined by the numerical solution of the relativistic Newton-Lorentz equation using a finite difference scheme. For an electron injected longitudinally with an energy of 5 keV and that starts at the radial midpoint of the cavity, it is accelerated up to an energy of about 90 keV using an electric field amplitude of 14 kV/cm and a frequency of 2.45 GHz. These results are compared with those obtained for another two points of injection located in different radial positions. This levels of energy can be used to produce soft X-ray which has some important medical applications like imageology. The results suggest that the particle-wave interaction using the cylindrical mode TE011 could be optimized through the application of a external magnetic field which is gradually growing in time to preserve the resonance condition and sustain the phase stability.