Comparative study of accelerating structures proposed for high power linac

The basic problems for design of high intensity linear accelerator are providing of high efficiency, reliability and reduction of induced radioactivity in its parts. In spite of very wide studies of processes leading to beam halo formation, there are no reliable methods to evaluate the small particle losses. The possible method based on analysis of beam dynamics simulations are discussed. The particle coordinates stored in output file and representing particle trajectories are considered as sequences of random points and the spectral density of the correlation function for each sequence is calculated. It allows one to study spectral properties of the particle trajectories as well as growth of their amplitudes. The method has been applied for analysis of beam dynamics simulation carried out for test accelerating focusing structures which represent an intermediate part of a hypothetical high power linac. The obtained results are discussed