Observations of Extensive Air Showers near the Maximum of Their Longitudinal Development

Abstract

Extensive air showers were studied at an altitude of 4200 m with an array of 11 scintillation detectors, and approximately 400 showers with sizes)15 x 10/sup 6/ particles were selected for detailed analysis. The function used in the analysis was the Greisen representation of the Nishimura-Kamata function. The ratios of the observed particle densities to the densities calculated from the trial function were plotted vs. distance from the core; the graphs indicate that the steepness of the lateral distribution decreases with the zenith angle. The integral intensities S of showers with sizes greater than N were then plotted vs. sec theta , and it is found that S for N near 30 x 10/sup 6/ is approximately constant for changes in sec theta near sec theta = 1, corresponding to maximum longitudinal development of showers with N approximately 30 x 10/sup 6/. A graph presenting the variation of N with x (slant thickness of atmosphere) at fixed S is also presented. (D.L.C.)