Turbulent Energy Transfer and Proton–Electron Heating in Collisionless Plasmas
Date
2022-12-19
Journal Title
Journal ISSN
Volume Title
Publisher
Astrophysical Journal
Abstract
Despite decades of study of high-temperature weakly collisional plasmas, a complete understanding of how energy is transferred between particles and fields in turbulent plasmas remains elusive. Two major questions in this regard are how fluid-scale energy transfer rates, associated with turbulence, connect with kinetic-scale dissipation, and what controls the fraction of dissipation on different charged species. Although the rate of cascade has long been recognized as a limiting factor in the heating rate at kinetic scales, there has not been direct evidence correlating the heating rate with MHD-scale cascade rates. Using kinetic simulations and in situ spacecraft data, we show that the fluid-scale energy flux indeed accounts for the total energy dissipated at kinetic scales. A phenomenology, based on disruption of proton gyromotion by fluctuating electric fields that are produced in turbulence at proton scales, argues that the proton versus electron heating is controlled by the ratio of the nonlinear timescale to the proton cyclotron time and by the plasma beta. The proposed scalings are supported by the simulations and observations.
Description
This article was originally published in Astrophysical Journal. The version of record is available at: https://doi.org/10.3847/1538-4357/aca479
Keywords
plasma physics, space plasmas, magnetohydrodynamics, plasma astrophysics
Citation
Roy, S., R. Bandyopadhyay, Y. Yang, T. N. Parashar, W. H. Matthaeus, S. Adhikari, V. Roytershteyn, et al. “Turbulent Energy Transfer and Proton–Electron Heating in Collisionless Plasmas.” The Astrophysical Journal 941, no. 2 (December 19, 2022): 137. https://doi.org/10.3847/1538-4357/aca479.