Electron flows in a low voltage gap exposed to an oblique external magnetic field

Summary form only given, as follows. It was recently found that steady-state cycloidal electron flows in a crossed-field gap are easily disrupted to a turbulent state, either by the presence of a small rf electric field across the gap, or by a small resistance. Such a collapse is insensitive to the level of the emitted current, and is amenable to a one-dimensional analysis. In the other limit where the external magnetic field is parallel to the gap´s electric field, such a collapse is not expected if the emitted current is below the Child-Langmuir value. In this paper, we investigate the general case where the external magnetic field is at an arbitrary angle with respect to the electric field. One-dimensional theories and simulations (PDP1) will be presented on the equilibrium, stability, and turbulent state of electron flows in such a low voltage (non-relativistic) gap. Implications for the noise generation in O-type and M-type electron guns are discussed.