An Analysis of Cosmic Ray Air Showers for the Determination of Shower Age

Abstract

A sample of 8651 air showers in the size range 104 . 3_106 . 2 has been analysed to determine the distribution of the measured age in terms of (i) the number of showers in a specified size range, and (ii) the radial distances in individual showers. It is shown that the radial age distribution in an individual shower leads to an average shower age approximately the same as the prediction of the electron-photon cascade theory. The other results include a study of the variation of (i) shower age, as measured by the x2-minimisation technique, with shower size of vertically incident showers, and (ii) the measured electron density at any point with its radial distance from the shower axis, as a function of the age of a large shower group with very small spread in size. A comparison of similar measurements with relevant theory is also included.