Nuclear-Electromagnetic Cascades in Glass, Iron, and Tungsten Absorbers

Abstract

Results of a Monte Carlo simulation of the longitudinal development of nuclear-electromagnetic cascades in glass, iron, and tungsten absorbers are presented. The simulation was fitted first to measurements made with an iron-absorber ionization spectrometer that was exposed at an accelerator to protons of known energies. The calculations were then extended to higher primary energies and to the other two absorbers. The results presented are for the energy range 10-1000 GeV. The maximum absorber depths considered are 56, 96, and 192 radiation lengths for glass, iron, and tungsten, respectively. Average cascade development curves and their fluctuations, as well as the ionization energy deposited by the cascades, are given as a function of the absorber depth. The accuracies with which the cascades can be used to determine unknown primary energies are also presented. It is shown that these accuracies increase rapidly with the total absorber depth up to an optimum depth for a given primary energy and given absorber. Over the energy range considered and for moderately large absorber depths, the accuracy also improves with increasing primary energy.