UHF Radio Pulses associated with Extensive Air Showers at Large Zenith Angles


FOLLOWING the initial observation of UHF radio pulses associated with extensive air showers at large zenith angles1, several experiments have been successful in detecting such pulses from the zenith2–5. These experiments indicate that the energy spectrum of the radio pulses falls with increasing frequency between 30 and 550 MHz, and that the shower threshold for detecting UHF pulses is > 2 × 1015 eV for showers incident from the zenith. Below 100 MHz the radio pulses arise by a coherent emission mechanism, but above this frequency the question of coherent or incoherent emission remains open.

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FEGAN, D. UHF Radio Pulses associated with Extensive Air Showers at Large Zenith Angles. Nature 227, 156–157 (1970). https://doi.org/10.1038/227156b0

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