Observations on extensive air showers IV. The lateral distribution of penetrating particles

Abstract

The lateral distribution of the penetrating component has been measured in showers containing more than 3 × 10⁶ charged particles. Between 300 and 600 metres, the distribution follows a power law with exponent 1.5, and falls more steeply beyond 500 metres. The median spread of the particles is about 500 metres. The interacting component falls off more steeply, and was not detectable beyond 160 metres. About 8.5% of all the particles m penetrating, and of these, about 10% are interacting. The results are compared with theoretical models, and good agreement is obtained with the predictions of Rozental, based on a Fermi model of the nuclear interaction. The results appear to be in conflict with the hypothesis that the primaries of air showers might be high energy dust grains.