ON THE CONTRIBUTION OF OFF-NUCLEI ELECTROPRODUCTION TO THE GENERATION OF ENERGETIC HADRONS IN ELECTROMAGNETIC SHOWERS

The calculation of high-energy hadron cascades in extended materials induced by electron beams in the GeV energy range is reconsidered. In particular, we estimate the contribution from hadronic interactions of high-energy electrons on nuclei as compared to hadron production by photons. Our estimate relies on the equivalent photon approximation. The interaction of the resulting quasireal photons with nuclei is described by the vector-meson dominance model and a Monte Carlo realization of the multistring fragmentation model, as discussed in ref. [1). For thin targets (as compared to the radiation length), hadronic interactions of the incident high-energy electrons on nuclei dominate the generation of high-energy hadrons. So far, hadroproduction by leptons was of no impor-tance for many practical applications in shielding and calorimetry: For example, due to the smallness of the corresponding hadronic cross sections, properties o