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Author: Scott D Baalrud
Requested Type: Poster
Submitted: 2018-02-28 13:22:26

Co-authors: J. Daligault

Contact Info:
University of Iowa
213 Van Allen Hall
Iowa City, IA   52242
United States

Abstract Text:
Collisional transport theories, such as that summarized by Braginskii, treat weakly magnetized plasmas in which the gyroradius of particles is much larger than the Debye length. In this case, the magnetic field influences the perturbation of the distribution functions on a macroscopic scale, but not the microphysics of binary collisions. In this work, we show that fundamentally different transport behaviors occur in strongly magnetized plasmas, where the gyroradius is smaller than the Debye length [1]. Two additional regimes are predicted based on the ratio of the gyroradius and either the Debye length or the distance of closest approach in a binary collision. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation of the one-component plasma were carried out spanning a broad range of magnetic field strength. These confirm that fundamental changes in transport properties occur at the regime boundaries. For example, in the strongly magnetized regime, the cross-field diffusion coefficient is found to have Bohm scaling ($1/B$) rather than Branginskii scaling ($1/B^2$). Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed. These results may be relevant to collisional electron transport in magnetic confinement fusion experiments, particularly in high-field devices, which can reach the strongly magnetized regime.

[1] S.D. Baalrud and J. Daligault, Phys. Rev. E 96, 043202 (2017).

If possible, I would like to be included in the Monday poster session (I may have to depart Tuesday afternoon).