Simulation of the electron coherent radiation process in a crystalline undulator

Abstract

When a high-energy electrons move in a crystal along one of the crystallographic planes the phenomenon of planar channeling is possible, in which the particles move in channels formed by the continuous potential of crystalline planes. Such particle motion in a crystal is conserved for most particles even for weak bending of crystalline planes of atoms. In [1-3] the process of channeled electrons radiation in such a device was considered. It was shown that the radiation spectrum of particles in the crystal in this case contains maxima associated with the period of oscillation of the channeled particles in the channel and with the period of the crystal planes bending. In [4] the radiation process in a crystalline undulator with large bending amplitude of the crystal planes was considered. In this case the trajectories of particles that are crossing the crystal planes are close to rectilinear. This allowed consider the radiation process in the first approximation in the interaction of particles with the crystal field analytically. In that paper the possibility of manifesting coherent and interference effects in radiation leading to high radiation intensity was demonstrated. Taking into account the incoherent effects in the particle scattering leads to particle mutual transitions from the sub-barrier to the above-barrier states and vice versa. Analysis of the radiation process in this case can be carried out on the basis of numerical simulation method for this process. In this paper such method is developed on the basis of the proposed in [5] method of the radiation process simulation in a direct crystal. We present some results of simulation of 1 and 10 GeV electron radiation in crystalline undulator at different values of the plane bending amplitudes. The calculations are performed in the dipole approximation of radiation theory with taking into account the recoil effect in radiation.