Dustin Fisher, Dartmouth College
Title: "Modeling the Large Plasma Device (LAPD)"
Abstract: 3D global two-fluid simulations are presented in an ongoing effort
to identify and understand the physics of instabilities that arise in the Large
Plasma Device (LAPD) at UCLA's Basic Science Facility. The LAPD, with
its wide range of tunable parameters and device configurations, is ideally
suited for studying space and laboratory plasmas. Moreover, the highly detailed
and reproducible measurements of the LAPD lend themselves amicably to
comparisons with simulations. Ongoing modeling is done using a modified
version of the Global Braginskii Solver (GBS) that models the plasma from
source to edge region in a fully 3D two-fluid code. The reduced Braginskii
equations are solved on a field-aligned grid using a finite difference method and
4th order Runge-Kutta time stepping and are parallelized on Dartmouth's
Discovery cluster. Recent progress has been made to account for the thermionic
cathode emission of fast electrons at the source, the axial dependence of the
plasma source, and it is now possible to vary the potential on the front and side
walls in a non-trivial way. I'll discuss the 10 days I spent out in Westwood as
an experimentalist helping to run the latest set of biasing tests on the LAPD
and will share my latest work on the growth and structure of turbulence in the
zero bias case.
Events are free and open to the public unless otherwise noted.