G.A. de Nolfo, A.J. Davis, A.W. Labrador, R.A. Mewaldt, S.M. Schindler California Institute of Technology, Pasadena, California, USA L.M. Barbier, E.R. Christian, K.E. Krombel, J.W. Mitchell, J.F. Ormes, R.E. Streitmatter NASA Goddard Space Flight Center O. Reimer Max-Planck-Institut fuer extraterrestrische Physik W. Menn, M. Hof, M. Simon Universitat Siegen R.L. Golden, S.J. Stochaj, W.R. Webber New Mexico State University I.L. Rassmussen Danish Space Research Institute
The rare isotopes of hydrogen and helium, 2He and 3He, in cosmic rays are believed to originate from the interaction of protons and helium within the galactic interstellar medium. The unique propagation history of these rare isotopes provides important constraints on galactic cosmic ray source spectra and propagation within the Galaxy. Hydrogen and helium isotopes were measured with the balloon-borne experiment, IMAX, which flew from Lynn Lake, Manitoba in 1992. The IMAX detector was designed to measure antiprotons and light isotopes using the combination of a super-conducting magnet spectrometer, aerogel cherenkov detectors, scintillation detectors, and a time of flight system. The energy spectrum of deuterium between 0.5 and 3.2 GeV/nucleon measured by the IMAX experiment as well as previously published results of 3He from the same instrument will be compared with predictions of cosmic ray galactic propagation models.