Proton Precipitation by a Whistler-Mode Wave from a VLF Transmitter

Protons with 50 keV E 530 keV were detected by sensors aboard satellite 1972-76B at an altitude of 700 km in the region conjugate to the transportable very-low-frequency (TVLF) transmitter which was being operated near Anchorage, Alaska (L approximately = 4). Temporal maxima in the proton count rates can be identified on a one-to-one basis with short pulsed transmissions by the VLF transmitter. The observed time delay between the center of a transmitted pulse and the detection of the next maximum in the proton count rate at the sensor agrees well with the delay predicted from a simple plasmaspheric model.