Review of electron beam microinstabilities and their relevance to EBIS devices

Plasma kinetic theory and some examples of microinstabilities are briefly reviewed. Although the velocity space configuration of any EBIS is inherently susceptible to a number of classical beam microinstabilities, the small radial dimension of an EBIS plasma may prevent modes from occurring in EBIS traps due to physical limitation. In EBIS devices with high electron beam compression, where the potential for beam microinstabilities is great, the radial dimension is smaller than the Debye length, which renders plasma kinetic theory invalid. Potential for parametric instabilities exists due to coupling of structure excited modes into plasma modes by various mode-mode coupling ''decay'' processes