RADCHARM++: A C++ routine to compute the electromagnetic radiation generated by relativistic charged particles in crystals and complex structures

The analytical theories of coherent bremsstrahlung and channeling radiation well describe the process of radiation generation in crystals under some special cases. However, the treatment of complex situations requires the usage of a more general approach. In this report we present a C++ routine, named RADCHARM++, to compute the electromagnetic radiation emitted by electrons and positrons in crystals and complex structures. In the RADCHARM++ routine, the model for the computation of e.m. radiation generation is based on the direct integration of the quasiclassical formula of Baier and Katkov. This approach allows one taking into account real trajectories, and thereby the contribution of incoherent scattering. Such contribution can be very important in many cases, for instance for electron channeling. The generality of the Baier-Katkov operator method permits one to simulate the electromagnetic radiation emitted by electrons/positrons in very different cases, e.g., in straight, bent and periodically bent crystals, and for different beam energy ranges, from sub-GeV to TeV and above. The RADCHARM++ routine has been implemented in the Monte Carlo code DYNECHARM++, which solves the classical equation of motion of charged particles traveling through a crystal under the continuum potential approximation. The code has proved to reproduce the results of experiments performed at the MAinzer MIkrotron (MAMI) with 855 MeV electrons and has been used to predict the radiation spectrum generated by the same electron beam in a bent crystal.