INTERACTIONS OF RELATIVISTIC AR-36 AND AR-40 NUCLEI IN HYDROGEN - ISOTOPIC PRODUCTION CROSS-SECTIONS

The interactions of Ar-36 projectile nuclei with energies of 361, 546, and 765 MeV/nucleon and Ar-40 nuclei with 352 MeV/nucleon, have been studied in a liquid-hydrogen target as part of a program to study inte ractions of relevance to the problem of cosmic-ray propagation in the interstellar medium. We have measured the cross sections for the produ ction of isotopic fragments of the projectile nuclei in these interact ions. The variations of these cross sections with mass, charge, and en ergy, are examined for insights into any systematic features of this t ype of fragmentation reaction that might aid predictions of other, unm easured cross sections. These cross sections are also compared with th e values derived from the most commonly used prediction techniques. It is suggested that these techniques could be improved by taking accoun t of the systematic features identified here.