Sub-THz radiation from dielectric capillaries with reflectors

In this report we present experimental investigations of the THz radiation generated from a corrugated and a non-corrugated capillary with reflectors, using a femtosecond electron beam of LUCX accelerator at KEK, Japan. We discuss measurements of the radiation angular distributions and their comparison with Particle In Cell simulations, and also investigate an off-central propagation of the beam in the capillaries based on experimental measurements and simulations.