Abstract Details
status: | file name: | submitted: | by: |
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approved | dfisher_sherwood_2015.pdf | 2015-04-02 13:58:17 | Dustin Fisher |
3D Two-fluid Braginski simulations of the Large Plasma Device
Author: Dustin M. Fisher
Requested Type: Consider for Invited
Submitted: 2015-01-19 15:12:47
Co-authors: B.N. Rogers, G. Rossi, D. Guisce
Contact Info:
Dartmouth College
6127 Wilder Laboratory
Hanover, NH 03755
USA
Abstract Text:
The Large Plasma Device (LAPD) is modeled using the 3D Global Braginskii Solver code (GBS). Comparisons to experimental measurements are made in the low-bias regime when there is an intrinsic E$times$B rotation of the plasma due to sheath effects. Comparisons show good qualitative and quantitative agreement with the equilibrium electric potential, density, and temperature profiles, the radial dependence of the density fluctuations, cross-correlation lengths, and radial flux dependence outside of the cathode edge. Kelvin Helmholtz (KH) turbulence is shown to be the dominant driver of cross-field transport throughout these simulations with drift waves playing a secondary role. Plasma holes and blobs found in the simulations are consistent with those measured in LAPD. Camera images also show good agreement with scale sizes of the predominant KH vortical structures which are the source of the holes and blobs. The addition of ion-neutral collisions at previously theorized values reduces the radial particle flux by about a factor of two from values that are somewhat larger than the experimentally measured flux to values that are somewhat lower than the measurements. This reduced flux results from weak suppression of KH and suggests that collisions have a modest quantitative impact in the low-bias regime.
Comments: