5-D Kinetic Modeling of ECH Plasmas in the HSX Stellarator

The HSX electron cyclotron heating (ECH) system is being upgraded to two 200 kW, 28 GHz gyrotron sources. This new system will allow increased total available ECH power as well as increased heating flexibility with a poloidally steerable launch assembly. Kinetic simulations using the global transport code GNET will model the evolution of the perturbed electron distribution function and radial electron transport due to ECH. GNET solves a linearized drift kinetic equation in five-dimensional phase space, allowing simulations of quasihelically symmetric (QHS) as well as asymmetric magnetic configurations. GNET will be used to determine ECH-driven electron fluxes and estimate modifications to the ambipolar radial electric field obtained from neoclassical theory. GNET calculations will be presented for 2\textsuperscript{nd}-harmonic X-mode at 0.5 Tesla and 1\textsuperscript{st}-harmonic O--mode at 1.0 Tesla operations. Implications for ECE and X-ray diagnostics will also be presented.