The Interaction Mean Free Paths and the Fragmentation Probabilities of Cosmic Heavy Nuclei at Energies Above 10 GeV/Nucleon

Abstract

A total of 7695 tracks of heavy nuclei were located in a systematic scanning of a stack of Brawley nuclear emulsion and the heavy nuclei with energies greater than 10 GeV/nucleon, 497 events, were accepted for the present investigation. The error in energy estimation was 30% and that in charge estimation by δ-ray counting was 0.25 units of charge for M-nuclei and about 0.5 units of charge for iron-groups.
The interaction mean free paths and the fragmentation probabilities of heavy nuclei at energies above 10 GeV/nucleon in nuclear emulsion were obtained and those in air and in hydrogen were deduced with reasonable accuracy. The interaction mean free paths and the fragmentation probabilities do not indicate any noticeable energy dependence over the wide energy range of a few GeV/nucleon to several hundred GeV/nucleon for heavy nuclei and of about 0.1 GeV/nucleon to several hundred GeV/nucleon for α-particles.