• F. Jafari Bahman, B. Maraghechi
  AUT, Tehran

Three-Dimensional simulation of Free-Electron Laser amplifiers at the presence of helical wiggler and ion-channel has been reported. The electromagnetic field is assumed to express in terms of the TE modes of a cylindrical waveguide in the absence of the electron beam. The final form of dynamical equations for the evolution of the slowly varying amplitude and wavenumber of TE mode is obtained by substitution of the vector potentials in to Maxwell’s equations. A cold, uniform, axisymmetric electron beam with a flat-top density profile has been considered for modeling the initial injection of the electron beam. The three-dimensional Lorentz force equation in the presence of a realistic helical magnetostatic wiggler, ion-channel electrostatic field and electromagnetic fields describes the electron dynamics. A set of coupled nonlinear first order differential equations is derived and solved numerically by Runge-Kutta method. The 10th-order Gussian quaderature technique is used for calculation of averages in the field equations. Finally, evolution of the radiation power and growth rate of the TE11 mode is shown.