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 ∼ 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.