Measurement of the Isotopic Composition of Galactic Cosmic Ray Carbon, Nitrogen and Oxygen

摘要

The results of an investigation of the isotopic composition of galactic cosmic ray carbon, nitrogen and oxygen (E approx. 80 to 230 MeV/amu) made using the U.C. Berkeley HKH instrument aboard the ISEE-3 spacecraft are reported. The combination of high mass resolution and a large statistical sample makes possible a precise determination of the relative isotopic abundances for these elements. In local interplanetary space we find: exp 13 C/C = 0.067 +- 0.008, exp 15 N/N = 0.54 +- 0.03, exp 17 O/O < 0.027, and exp 18 O/O = 0.019 +- 0.003. (ERA citation 04:050642)