Precipitation of radiation belt electrons by man-made waves A comparison between theory and measurement

The temporal and spectral shape and the absolute flux level of particle pulses precipitated by a VLF transmitter are examined from a theoretical point of view. A test-particle model of the gyroresonant wave-particle interaction is applied to the parameters of the observed cases for calculating the precipitation characteristics. The temporal shapes of the precipitation pulses are found to be controlled (1) by the pitch angle dependence of the particle distribution near the edge of the loss cone and (2) by the multiple interaction of the particles with the waves due to significant atmospheric backscatter.