Simple-power-balance model for microwave heating in EBT

A simple model is presented for the production and absorption of ordinary and extraordinary mode energy in various regions of the ELMO Bumpy Torus plasma. The plasma is divided into two regions: (I) the low magnetic field side of the extraordinary mode cutoff and (II) the high field side of the cutoff. Energy balance equations are written for the sources (injection, mode conversion, and tunneling) and sinks (mode conversion, absorption, and tunneling) in each region, and simplified models are introduced to account for each of these processes. Since a typical ray makes several reflections from cavity wall surfaces before being absorbed, additional simplifying assumptions are made that the wave fields are an isotropic incoherent superposition of plane waves and that the energy density of each mode is uniform in a given region