Energy transfer and proton-electron heating in turbulent plasmas
Presentation Type
Talk
Presenter Format
In Person Meeting Talk
Topic
Fundamental Processes in Comparative Magnetospheres
Start Date
13-5-2022 11:00 AM
Abstract
Despite decades of study of high-temperature weakly-collisional plasmas, a complete understanding of how energy is transferred between particles and fields 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 scale, no study has reported direct evidence correlating the heating rate with MHD-scale cascade rates. Using kinetic simulations and in-situ spacecraft data, we show the connection between the fluid-scale energy flux and the total energy dissipated at kinetic scales. The proton versus electron heating is controlled by the ratio of non-linear time scale to the proton-cyclotron time and increases with the total dissipation rate. These results advance a key step toward understanding dissipation of turbulent energy in collisionless plasmas.
Energy transfer and proton-electron heating in turbulent plasmas
Despite decades of study of high-temperature weakly-collisional plasmas, a complete understanding of how energy is transferred between particles and fields 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 scale, no study has reported direct evidence correlating the heating rate with MHD-scale cascade rates. Using kinetic simulations and in-situ spacecraft data, we show the connection between the fluid-scale energy flux and the total energy dissipated at kinetic scales. The proton versus electron heating is controlled by the ratio of non-linear time scale to the proton-cyclotron time and increases with the total dissipation rate. These results advance a key step toward understanding dissipation of turbulent energy in collisionless plasmas.
