Switching as a dynamical process in electron diodes

The transient nature of electron diode dynamics, caused by a weak amplitude switching of the collector voltage, is investigated both analytically and numerically. Based on the Lagrangian flow description, an analytical solution is found, which depicts the numerical findings accurately. Discussing in detail the trajectories of the electrons, we recognize two groups of electrons, behaving differently depending on whether they are already present in the diode at the moment of switching ("old" electrons) or they are injected later ("fresh" electrons). Their mutual interaction via the electric field yields a rapid, nonlinear transition between the initial and the final steady state, the spatial-temporal behavior of which could be extracted by solving a retarded differential equation for the perturbed emitter electric field and by a proper transformation back to the Eulerian space. (C) 2003 American Institute of Physics.