Isotopic Composition Measurements of Cosmic-Ray Nuclei with Z >= 10 Made Using a New Technique

We have recently measured the isotopic composition of Z > 10 cosmic-ray nuclei using a new technique employing a combination of Cerenkov and total energy counters. An effective mass resolution 0A amu is obtained for particles of energy between 400 and 500 MeV per nucleon with charge between 12 and 16. The preliminary mass distribution of nuclei with charge from 12 to 28 will be presented along with estimates of errors involved in the absolute mass assignments. Subject headings:abundances, cosmic rays - cosmic rays