Numerical Modeling of Suprathermal Electron Transport in the Solar Wind: Effects of Whistler Turbulence with a Full Diffusion Tensor

• Published in: The Astrophysical journal Vol. 924; no. 2; pp. 113 - 124
• Main Authors: Tang, Bofeng, Zank, Gary P., Kolobov, Vladimir I.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01-01-2022; IOP Publishing
• Subjects: Astrophysics; Diffusion; Diffusion coefficient; Electron transport; Electron velocity distribution; Heat flux; Mathematical analysis; Mathematical models; Particle interactions; Solar wind; Solar wind effects; Tensors; Transport equations; Turbulence; Velocity distribution; Whistler waves; Whistlers; Wind effects
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ac36c9

Abstract
The electron VDF in the solar wind consists of a Maxwellian core, a suprathermal halo, a field-aligned component strahl, and an energetic superhalo that deviates from the equilibrium. Whistler wave turbulence is thought to resonantly scatter the observed electron velocity distribution. Wave–particle interactions that contribute to Whistler wave turbulence are introduced into a Fokker–Planck kinetic transport equation that describes the interaction between the suprathermal electrons and the Whistler waves. A recent numerical approach for solving the Fokker–Planck kinetic transport equation has been extended to include a full diffusion tensor. Application of the extended numerical approach to the transport of solar wind suprathermal electrons influenced by Whistler wave turbulence is presented. Comparison and analysis of the numerical results with observations and diagonal-only model results are made. The off-diagonal terms in the diffusion tensor act to depress effects caused by the diagonal terms. The role of the diffusion coefficient on the electron heat flux is discussed.