Research on 2.5-dimensional nonlinear beam-wave interaction program of klystrons

In high perveance klystrons, violent variation of electron beam radius and electron transverse velocity is met with, and the energy exchange between kinetic electrons and gap field is a nonlinear process. For accurately describing these physical phenomena, we have put forward the corresponding physical model and further developed the 2.5-dimensional computation program ISP. Moreover, by use of this tool, we analyzed a practical S-band high peak-power klystron in detail. By comparing with the calculation results using 1-dimensional program and experimental data, we noticed that this poly-dimensional program can approach the real situation with higher precision.