PPPL-5374
Modeling of lithium granule injection in NSTX using M3D-C1
Authors: A. Fil, E. Kolemen, N. Ferraro
Abstract: In this paper, we present simulations of pedestal
control by lithium granule injection (LGI) in NSTX. A model for
small granule ablation has been implemented in the M3D-C1 code
(Jardin et al 2012 Comput. Sci. Discovery 5 014002), allowing the
simulation of realistic Lithium granule injections. 2D and 3D
simulations of Li injections in NSTX H-mode plasmas are performed
and the effect of granule size, injection angle and velocity on the
pedestal gradient increase is studied. The amplitude of the local
pressure perturbation caused by the granules is found to be highly
dependent on the solid granule size. Adjusting the granule injection
velocity allows one to inject more particles at the pedestal top. 3D
simulations show the destabilization of high order MHD modes whose
amplitude is directly linked to the localized pressure perturbation,
which is found to depend on the toroidal localization of the granule
density source