Characteristics of Giant Air Showers of Energies Around 50 Eev Observed by Agasa

Since 1990 the Akeno Giant Air Shower Array (AGASA) has been operational in a stable mode and about 20 showers of energies larger than 40 EeV have been observed. For these giant air showers, we have determined the average lateral distributions for charged particles, detected by scintillation counters on the surface, and for muons (threshold energies above 0.5 GeV), detected by proportional counters placed under concrete or iron absorber. Our study shows that the empirical formulae determined earlier [1],[2] from a study of showers of energies below 10 EeV can also be applied to showers of energies upto 100 EeV for core distances upto 4 km for particles detected with surface detectors and upto 3 km for muons.