Cosmic Ray Isotopes

Abstract

Since this is the first rapporteur talk on cosmic ray isotopes in thirteen Cosmic Ray Conferences, I will begin by briefly summarizing our interest in isotopic composition as follows: a) Isotopes, not elements, are the result of various nucleosynthesis processes. Thus, we must know the isotopic composition of cosmic rays in order to adequately exploit the relationship of cosmic rays and stellar processes. b) Isotopes, not elements, are the result of secondary fragmentation processes, either in cosmic ray source regions or in the interstellar medium. Thus, we must know the isotopic composition in order to completely unravel source composition from secondary composition. c) Isotopes, not elements, are radioactive. Thus, we must know the isotopic composition in order to take full advantage of various radioactive nuclei as cosmic ray clocks which can be used to determine the age of cosmic rays. With this short summary, I now turn to a brief review of the results presented at this conference. Since I can't possibly discuss each new measurement, I have chosen the following topics: I) Hand He isotopes, II) Be isotopes, III) Al isotopes, IV) Fe isotopes, V) cross sections and model calculations, and VI) instrumental considerations.