Recent events from the Magneto-Fluid Dynamics Seminar are listed below. To see the complete list of events, visit the seminar's main page, here.
Tuesday, December 4, 201811AM, Warren Weaver Hall 905
Equilibrium and near-equilibrium dynamics of plasma in magnetic confinement devices
Wrick Sengupta, Courant Institute, NYU
Magnetic confinement of plasmas in toroidal devices offers a broad variety of challenging and interesting mathematical problems of great relevance to the nuclear fusion community. Although well understood in two dimensions, the fundamental question of obtaining an equilibrium of the underlying magnetohydrodynamics (MHD) model in a three-dimensional space remains an open problem. This poses considerable theoretical and computational challenges for fusion engineers and plasma physicists. Asymptotic analysis offers valuable tools and great physical insight in tackling some of these questions. After discussing the mathematical difficulties that arise from the basic system of partial differential equations governing three-dimensional MHD equilibrium, I will present a variety of asymptotic expansion methods to resolve these issues and obtain a self-consistent solution order by order. In particular, I shall demonstrate that the expansions can be carried to all orders and thereby provide direct evidence for the existence of large classes of three-dimensional MHD equilibria in a toroidal system. I will show that our analysis provides theoretical explanations for certain experimentally observed self-organized plasma states near certain magnetic surfaces where the magnetic field closes on itself after one toroidal turn.This work has been done in collaboration with Harold Weitzner (NYU), Joshua Burby (Los Alamos National Lab) and Adil Hassam (UMD College Park).
Tuesday, November 13, 201811AM, Warren Weaver Hall 905
Progress toward efficient direct solution of the nonlinear inelastic Boltzmann equation
George Wilkie, Chalmers University of Technology
Recent advances in applied mathematics (Gamba and Rjasanow, JCP 2018) make direct solution of the Boltzmann equation particularly accessible. A newly-developed implementation has been optimized, parallelized, and rigorously benchmarked. Features include general-cross-section large-angle, inelastic, and/or self-collisions. The fully conservative
discrete collision operators are pre-computed and stored on an online database, making time advancement remarkably efficient on local workstations. I will also discuss possible applications for this tool including discharges, reentry blackout, tokamak divertors, runaway electrons, carbon sequestration, and more.
Friday, September 21, 20182PM, Warren Weaver Hall 1302
Conference in Honor of Professor Eliezer Hameiri
2:00 - 2:15 Comments by P. Deift (NYU CIMS) and H. Weitzner (NYU CIMS) 2:15 - 2:45 Amitava Bhattacharjee (Princeton University)
The Dynamo Effect in Laboratory and Astrophysical Plasmas
2:45 - 3:15 Luca Guazzotto (Auburn University)
Plasma Flows in Tokamaks and Transonic Equilibria
3:15 - 3:25 Coffee break 3:25 - 3:30 Comments by A. Cerfon (NYU CIMS) 3:30 - 4:00 P. Morrison (U. Texas Austin)
Stability Subject to Dynamical Accessibility
4:00 Closing remarks by R. Caflisch (NYU CIMS) and small reception