Experiments on the scattering of fast electrons by Alfv\'{e}n waves

POSTER

Abstract

High energy ions and electrons with anisotropic distribution functions can be trapped in the earth's radiation belts for months, which pose a danger for satellites. A electron population with large $v_{\perp}$ and was introduced in the afterglow of the background LAPD plasma ($n_e =2.0e^{11} cm^{-3}$, $T_e = .25 eV$) .Microwaves at 2.45 GHz were launched into the plasma at an axial and radial location where $f_{micro} = f_{UH}$. A small (2 cm dia) electron hot spot was generated. Shear Alfv\'{e}n waves (f = 192 kHz) launched by an orthogonal loop antenna, with magnitude $B_{wave} \sim 2 G$ destroyed the hot spot within 10 cycles. The hot spot returns when the Alfven wave is shut off. Space-time evolution of the plasma density, flow and electron are presented. The mechanism of the electron de-trapping is under investigation. Planned experiments involve the interaction of fast ion rings with shear Alfv\'{e}n waves, and whistler waves with the anisotropic electrons.

*This work supported by The Office of Naval Research under a MURI award

Authors

  • Alex Gigliotti

    • UCLA, Dept Physics
    • UCLA Dept of Physics
  • Walter Gekelman

    • University of California, Los Angeles
    • UCLA, Dept Physics
    • UCLA Department of Physics and Astronomy
    • UCLA
    • UCLA Dept of Physics
  • Patrick Pribyl

    • UCLA Dept of Physics
  • Yuhou Wang

    • UCLA Dept of Physics
  • A. Karavaev

    • Univversity of Maryland
    • Univ. of Maryland
  • Xi Shao

    • Univversity of Maryland
    • Univ. of Maryland
    • University of Maryland, College park, MD
  • K. Papadopoulos

    • University of Maryland, College Park, Maryland, USA
    • Univversity of Maryland
    • Univ. of Maryland