Direct Numerical Simulation of ICRF Wave-Particle Interaction

72516S03-I Traditional, linear radio frequency (RF) theory is not valid when nonlinearities play a role, such as the launch and absorption of ion Bernstein waves in fusion plasmas. Although more computationally demanding, direct numerical simulation retains more physics, including nonlinearities, and therefore has broader validity. In this project, direct particle-in-cell (PIC) simulations of ICRF wave-particle interaction will be used to complement traditional, linear RF theory in areas where nonlinear effects are believed to be important, such as antenna coupling and absorption of ion Bernstein and lower-hybrid waves. Direct calculation of the dielectric and quasilinear tensors will be used to improve the analytic approximations used in linear RF theory. In Phase I, an open-source PIC code will be upgraded so it can be used for ICRF wave-particle simulations. In particular, a loop antenna will be added, a gyro-PIC algorithm will be implemented to remove the fast electron gyration, and code for direct calculation of the conductivity tensor also will be added. Commercial Applications and Other Benefits as described by awardee: The resulting software tools and expertise could be used to sell consulting services to fusion experiments in the area of antenna design and operation.