Perspective on EBT electron ring theory

The hot electron population in ECH plasmas has been analyzed by a wide array of theoretical approaches and techniques. Topics considered have included heating, equilibria, stability, and loss mechanisms, with the degree of sophistication increasing year-by-year. The heating studies have gone from non-relativistic to relativistic, the equilibrium studies have taken increasing account of geometry and adiabaticity, the stability work has begun to recognize the interactive nature of the ring-core problem, and loss studies have included both classical, single particle, and collective processes. A survey of these theoretical topics will review the capabilities and uncertainties of theory in addressing these various topics, including limitations imposed by computing capability, existing analytic theory, and geometry complications and uncertainties. The results of existing theory will be combined to give a conceptual picture of the formation and behavior of the hot electron system in present devices, as well as the changes expected as larger and more reactor-like experiments are brought into operation