A new wave-particle interaction mechanism

Type: Presentation

Venue: AGU Fall Meeting 2012


Edisher K. Kaghashvili (2012) A new wave-particle interaction mechanism. AGU Fall Meeting, San Francisco, CA.

The source of energy for both coronal heating and wind acceleration is long known, but the exact nature of the photospheric energy transport and deposition is still a puzzle. It was long known theoretically and recent observations undoubtedly confirmed an important role that Alfvén waves play in these processes. While the observed spectrum is in the low-frequency range, existing wave dissipation mechanisms favor the high-frequency spectrum that can effectively interact with particles. In this work, a new process of the wave energy deposition is presented that is effective for the observed low frequency spectrum. The process is based on the waves driven by the linearly polarized Alfvén wave in the magnetic field-aligned cross-field shear flow. It is shown that the driven waves produce a nonzero time average electric field. A specific example is considered using solar coronal hole plasma parameters. It is shown that the magnitude of the generated electric field parallel to the background magnetic field far exceeds Dreicer electric field values for both cool and hot coronal plasma. Effects of the driven wave generated electric field on a single particle are examined. It is shown that the driven waves exert the wave force on particles, which can be important for the solar wind dynamics. As a result of this force, it is shown that such important characteristics of the single particle dynamics as the total kinetic energy and parallel velocity of the particle are not conserved. We argue that the electric fields generated by the driven waves can be important in the laboratory, terrestrial and astrophysical plasma processes where the inhomogeneous flows are present.