This project will fly a passive glass detector as part of the payload on a large balloon to be launched from McMurdo, Antarctica. The purpose is to measure the abundance of various isotopes of moderately heavy (near iron) cosmic ray nuclei, to distinguish between models of stellar evolution which are sensitive to the isotopic abundance ratios. The special glass is exposed for several days at 120,000 feet altitude to the radiation and, after recovery, it is etched with a strong acid. This process reveals the tracks left by energetic cosmic rays that penetrate the glass. Study of the etched tracks can accurately determine the mass, charge and energy of the nuclei that caused them. This project is jointly supported by NSF's Division of Polar Programs and Division of Physics and by NASA's Sub-orbital Program.
