Abstract
Electron-beam-excited plasma-ion oscillations can either be locked into stable modes or be chaotic and continually making transitions between different modes. A frequency analysis of the chaotic oscillations could yield new information about the non-linear properties of such modes and their damping. It is not fully understood why beam-excited plasma-electron and plasma-ion oscillations often, possibly invariably, occur in alternate pulses, the one stopping when the other starts, nor why oppositely-directed interacting electron beams explode laterally and single beams end in a ‘blob’ when they excite oscillations. Possible experimental approaches to obtaining new information about such oscillations are indicated.