Integrative Predictive Models for ICRF-Edge Plasma Interactions

75771-The coupling of intense radio frequency waves in the ion range of frequencies (ICRF) to the edge plasma of a fusion device produces strong nonlinear interactions with the plasma and surrounding material walls. These effects must be controlled in order to protect the antenna and to obtain efficient heating of the core plasma. This project will develop a quantitative numerical simulation of this problem for use in antenna design and experimental interpretation. Ten years of research on the interaction of radio frequency waves with the tokamak edge plasma and on edge plasma transport has yielded a number of models of various nonlinear phenomena that are relevant to the present problem. These will be incorporated into a suite of integrated computer codes to yield a unified and quantitative picture of the antenna-plasma interaction. Phase I will develop and test prototypes of two computer codes that compute (1) the propagation of radio frequency waves in the ICRF near the antenna, and (2) the low frequency plasma response to the nonlinear effects (e.g. plasma density profile in the scrape-off-layer). The coupling of these codes will occur in Phase II. Commercial Applications and Other Benefits as described by the awardee: An improved numerical model of the ICRF-edge plasma interactions should provide better antenna design and experimental data analysis for ICRF-heated fusion plasmas. Potential applications not only include such fusion facilities as the National Spherical Torus Experiment (NSTX) and the International Tokamak Experimental Reactor (ITER), but also plasma processing.