TOTAL CHARGE AND MASS CHANGING CROSS-SECTIONS OF RELATIVISTIC NUCLEI IN HYDROGEN, HELIUM, AND CARBON TARGETS

This is the first in a series of papers describing the results of a systematic study of total, elemental, and isotopic cross sections measured in hydrogen, helium, and carbon targets. These fragmentation studies are based on measurements using 42 beams of 12 separate nuclei from C12 to Ni58. This has resulted in the measurement of more than 100 secondary elemental cross sections and over 300 secondary isotopic cross sections in addition to the total charge changing and mass changing cross sections reported in this paper. These measurements have been made at energies from 300 to 1700 MeV/nucleon and include ten separate energies for Fe56, for example. The measurements have been made with the objective of interpreting the production of secondary nuclei during cosmic-ray propagation in the galaxy in order to better estimate the source elemental and isotopic composition of cosmic rays. At the same time they provide a valuable data base for nuclear physics and the understanding of peripheral interactions of energetic heavy nuclei. In the work reported in this paper 100 total charge changing and mass changing cross sections have been measured for various targets and energies. The mass changing cross sections we measure are found to agree with earlier cross section measurements using energetic protons incident on targets composed of heavier elements to within 2% in cases where a comparison can be made. The systematics of this new data set are described and a new, more accurate cross section formula is presented and discussed. © 1990 The American Physical Society.