• A. Opanasenko, V.S. Kovalenko, K. Kramarenko, V.A. Kushnir, V.V. Mytrochenko, Z.V. Zhiglo, A. I. Zykov
  NSC/KIPT, Kharkov

At present work the results of numeral simulation of electron dynamics in an unhomogeneous disk-loaded waveguide which is used in the S-band linac are presented. Two approaches taking into account the self-fields of beam radiation are considered: the first method estimative based on the power diffusion equation; the second one based on of self-consistent equations of field excitation and particles motion. The self-consistent approach showed the presence of substantial phase slipping of particles in the homogeneous part of the rf structure, conditioned by the reactive beam loading.

• V.V. Mytrochenko, M.I. Ayzatskiy, V.A. Kushnir, A. Opanasenko, S.A. Perezhogin, Z.V. Zhiglo
  NSC/KIPT, Kharkov

Simulation results of subpicosecond bunch formation due to phase motion of electrons in traveling wave are presented. It has been shown that at satisfying phase conditions of electron injection that are necessary for velocity bunching, relative phase velocity of the total wave excited both by RF generator and particles becomes different from unit increasing bunch compression. Simulation of transportation of obtained 8.5 MeV bunches through undulator with a period of 90.6 mm and estimation of bunch form-factor at 446 harmonic of bunch repetition rate of 2797.15 MHz also was carried out. The data obtained allow to expect coherent radiation from undulator at wave-length of 240 um.