Numerical simulation models of forming systems of intense gyrotron helical electron beams

Potentialities of different numerical models for calculation of helical electron beams parameters are analyzed. The most simple and economical with respect to the calculation time static mono-velocity model, as well as the model considering initial velocities of electrons and the dynamic model based on the PIC-method and on the quasi-static concept of the electric field are described, The main physical results obtained on the basis of each model mentioned above are given.