On the influence of the voltage pulse profile on the process of particle trapping in the adiabatic trap of the gyrotron

We analyze the process of stabilization of electron beam parameters in a gyrotron for different profiles of the front of the accelerating-voltage pulse and the case of a large space charge trapped in the adiabatic trap. The duration of the portion of the pulse front, within which the electrons are reflected from the magnetic mirror and trapped, is at least an order of magnitude shorter than the entire length of the pulse front and is comparable with the characteristic time of potential oscillation development in the trap at great values of the pitch factor. The results of numerical analysis of the electron beam within the framework of models with finite durations of the voltage pulse front and instantaneous switch-on of the voltage showed that the steady-state values of the beam parameters are only weakly dependent on the pro.le of the pulse front. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 5, pp. 425–433, May 2008.