ISOMAX: A Balloon-borne Instrument to Study Beryllium and Other Light Isotopes in the Cosmic Radiation

The Isotope Magnet Experiment (ISOMAX), a balloon-borne magnetic rigidity spectrometer designed to measure the light isotopes of the cosmic radiation, is currently under construction. A major goal of the experiment is accurate measurement of the abundance of the radioactive isotope ^(10)Be up to relativistic energies (~ 4 GeV/nucleon). ISOMAX will make use of state-of-the-art instrument technology based on evolutionary development of detectors previously constructed by this collaboration. The ISOMAX detector complement will include high-resolution drift chambers for trajectory detennination, a time-of-flight system, and a Cherenkov detector utilizing silica aerogel radiators. For rare isotopes, a large exposure factor is required to obtain statistlcaJly significant results. ISOMAX is specifically designed to take advantage of the emerging capability for long-duration balloon flights, with a two week dewar lifetime and low-power electronics. The first flight of ISOMAX is planned for 1995