Transverse dynamics of the relativistic electron beams passing through coaxial cylindrical dielectric waveguides

Transverse beam dynamics is a critical issue for the wakefield accelerating structure development. The passing length of the driving high current low energy bunch, which generates wakefields, is dominated by strong deflecting field of HEM (Hybrid Electro Magnetic) modes. Properly adjusted FODO focusing system allows to keep the bunch off the dielectric walls along the waveguide axis. We present here our investigation results on the high order (m>1) HEM modes effect on the transverse beam dynamics of the driving 20-30 nC beam. Our analysis was carried out with the help of the in-house code BBU´3000 especially developed for the dielectric loaded wakefield accelerator. The calculation results will be used for the newly updated Argonne Wakefield Accelerator for experiments with the 75 MeV electron drive beams.