Nonlinear beam loading and dynamical limiting currents in a high-power microwave gap

Abstract
We show that the intense space charge of a high-current beam may increase the gap capacitance by a factor of 2 to 3 over the vacuum value. The limiting current under an ac gap voltage is computed and compared with the steady-state value. The implications of these findings on operation efficiency and frequency stability of high-power microwave devices are discussed.