The Study of high-energy γ-rays produced by cosmic radiation at 40 000 feet part ii. the energy spectrum of cascades and its interpretation

Abstract

Abstract The results of the measurement of the density of electromagnetic cascades described in Part I are discussed. For events initiated by single γ-rays from the atmosphere it is found that the integral spectrum of cascade energy may be represented by a power law with exponent -3·0 ± 0·20 for the range 1200–8000 Bev. The corresponding exponent for cascades associated with local nuclear interactions is − 2·9 ± 0·2 in the same energy range. The γ-ray spectrum may be used to calculate the pion spectrum in the atmosphere and this is compared with that deduced from measurements on μ-mesons at sea-level or underground. Reasons for the resulting discrepancies are discussed. The flux of cascades associated with local nuclear events when compared with the nuclear flux deduced from measurements on extensive air showers yields values for the fractional energy, K π, radiated as pions in collisions of nucleons in the energy range 10 000–100 000 Bev. It is found that K π, decreases strongly with increasing primary e...