The Electronic Component at Low Altitudes Produced byπ-Meson Decay

Abstract

The intensity of the electronic component at low altitudes produced by $\ensuremath{\pi}$-meson decay (designated as the ${E}_{\ensuremath{\pi}}$ component) has been obtained as a function of zenith angle and altitude by subtracting from the experimentally observed soft component those electrons arising from the collision and decay processes of $\ensuremath{\mu}$-mesons (designated as ${E}_{\ensuremath{\mu}}$ electrons). Extensive auxiliary studies of the corrections required in such soft component studies are described, and experimental requirements are stated for a precise telescopic study of the soft component. In particular, it is shown that the usual method of correcting a Geiger counter telescope for side showers is incorrect, and also that the effect of wall-generated secondaries should be considered. It is shown that the ${E}_{\ensuremath{\pi}}$ component of energy greater than 30 Mev can be represented as a function of zenith angle $\ensuremath{\theta}$ and atmospheric depth $h$ by the expression $I({E}_{\ensuremath{\pi}},h,\ensuremath{\theta})=0.70\mathrm{exp}(\ensuremath{-}\frac{h}{160cos\ensuremath{\theta}}){\mathrm{cm}}^{\ensuremath{-}2}invsec{\mathrm{sterad}}^{\ensuremath{-}1},$ for $\ensuremath{\theta}<~{60}^{\ensuremath{\circ}}$ and $h>~700$ g ${\mathrm{cm}}^{\ensuremath{-}2}$.