Switching of nonneutral plasma diodes. II. Numerical results

The switching of a pure electron diode between two equilibria of different current status is numerically investigated by means of an updated Vlasov code. The emphasis is on finite jumps of the applied voltage as well as on jumps in the vicinity of a critical point, namely, the space-charge-limited (SCL) point, which marks the transition between a high current normal $C$ branch—a state without electron reflection—and a low current stable $B$ branch—a state where electrons are partially reflected. The main result obtained is a strong delay of the transition time in case of a switching close to an SCL point. In case of a switching to an unstable part of the $B$ branch, large amplitude coherent oscillations arise corresponding to limit cycles in the language of nonlinear dynamics.