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

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.