Theory of Large‐Amplitude Oscillations in the One‐Dimensional Low‐Pressure Cesium Thermionic Converter

The large‐amplitude oscillations in a one‐dimensional, low‐pressure cesium thermionic converter are analyzed. With the help of results obtained from computer calculations designed to simulate the operation of the converter, the current oscillations are explained in terms of the changing forms of the potential distribution in the system. The variations in the form of the potential function are explained by means of the concept of a ``temporary dc state.'' Such a state differs from the ideal self‐consistent state in that the electrons and the potential adopt new distributions while the ion distribution stays the same as in the self‐consistent state. In fact, the ions are treated as too heavy to respond to the new potentials while the electrons adjust themselves rapidly to them. The existence of a temporary dc state is decided by solving a static problem only; but if such a state exists, then there is a possibility for relaxation‐type oscillations in the system with frequencies characteristic of the ions.