Tokyo large air shower project

Abstract

A preliminary experiment to detect large air showers by means of radio echoes and to study the high-energy end of the primary cosmic-ray energy spectrum has been started at this Institute. The fundamental idea and the first approach of the experiment are presented. Using the telemetry system between two pairs of a simple scintillation array, which has been constructed to identify and calibrate the showers in the above experiment, the decoherence curve of air showers has been measured between 100 and 1 300 m together with the particle density in each detector. This simple experiment will give the power of the size spectrum above 109.