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Wave Interactions with Geomagnetically Trapped Particles Martin Walt Department of Electrical Engineering Stanford University, Stanford, California, 94305, U. S. A. Tel: (650) 723-2690; Fax:(650) 723-9251; E-mail: walt@nova.stanford.edu Geomagnetically trapped electrons are readily removed from the radiation belts by pitch angle scattering with plasma waves. Much theoretical and experimental evidence supports the argument that VLF whistlers, plasmaspheric hiss, chorus, and ground based transmitters contribute to this removal. However, there is considerable uncertainty about which of these wave sources is most important in the various regions of the magnetosphere. A better knowledge of the wave fields throughout the magnetosphere is needed for a better assessment of the overall importance of the electron-wave interaction process. The experimental evidence for the scattering of trapped ions by waves is much less abundant and suggests that pitch angle scattering of protons is a slow process. Many estimates of proton transport in the radiation belts neglect pitch angle scattering although it is clear from theory that such scattering must occur. Recent data bearing on wave-proton scattering will be presented. |