Leslie Greengard

Abstract: An integrated gyrokinetic particle simulation with turbulence and neoclassical physics in a diverted tokamak edge plasma has been performed. Neoclassical equilibrium gyrokinetic solutions in the whole edge plasma have been separated from the turbulence activities for the first time, using the massively parallel Jaguar XT3 computer at Oak Ridge National Laboratory. The equilibrium solutions in an H-mode-like edge plasma condition show strongly sheared global ExB and parallel flows in the entire edge plasma including the pedestal and scrape-off regions. In an L-mode-like edge plasma condition, the sheared flows in the pedestal layer are much weaker, supporting the conjecture that the neoclassical flow-shear may play a significant role in the H-mode physics.

TL;DR: In this paper, the authors present a decoupled formulation for the problem of electromagnetic scattering from perfect electric conductors, where the equations for the vector and scalar potentials are decouple and the boundary conditions on the potentials themselves, rather than on the field quantities.

TL;DR: In this article, a more physical regularization based on restricting the unknown boundary to be band-limited in a suitable sense is presented. But the problem of reconstructing the shape of an impenetrable sound-soft obstacle from scattering measurements is not addressed.

TL;DR: In this paper, the authors present a simple, accurate method for solving consistent, rank-deficient linear systems, with or without addi- tional rank-completing constraints.

TL;DR: A fast summation method for lattice sums of the type which arise when solving wave scattering problems with periodic boundary conditions, which has super-algebraic convergence and requires only milliseconds of CPU time is presented.