Boulder, Colorado - May 21, 2015:
Physicists Thomas Jenkins and David Smithe of Tech-X Corporation have been selected to receive a 2015 ASCR Leadership Computing Challenge (ALCC) award from the U.S. Department of Energy for their proposal, “Modeling RF-induced Sheath Effects and Parasitic Losses in Magnetic Fusion Experiments.” This proposal focuses on the numerical modeling of inefficiencies which arise when radiofrequency (RF) power is used to heat and control plasmas in magnetic fusion experiments.
Large sheath potentials, which ensue as plasma sheaths form near antenna structures, are associated with sputtering, high-Z impurity contamination, and radiative cooling of the core plasma. The dynamics of nonlinear wave processes in the plasma edge may also reduce reactor efficiency, as power flow to the reactor core is diverted to excite slow waves in the edge. Large-scale simulations of antenna operation in Alcator C-Mod and NSTX will be carried out, using Tech-X's VSim code, to explore these phenomena. The simulations will be validated against experimental data, and the role of the inefficiencies in projected ITER operational regimes will also be assessed.