The Trans-Iron Galactic Element Recorder for the Ultra-Long Duration Balloon Project Demo 2000

The Trans-Iron Galactic Element Recorder (TIGER) for the Ultra-Long Duration Balloon project Demo2000 (TD2K) is designed to measure the abundances of all elements in the Galactic Cosmic Rays (GCRs) with 26 ≤ Z ≤ 40 and energies above 300 MeV/nucleon. TD2K's flight is expected to approach 100 days in length. Launch will be from New Zealand in 2001. TD2K will have sufficiently good resolution to measure the individual abundances of the odd-Z elements between Z=26 and Z=40 for the first time. Measurements of odd-Z nuclei are important for distinguishing between the effects of first ionization potential and volatility in the injection process for ultraheavy GCRs, for models of nucleosynthesis, and constraining models of cosmic-ray propagation at short pathlengths. TD2K uses a combination of Cherenkov and scintillation counters to determine the atomic number and energy of incident cosmic rays, and a coded cintillating-fiber hodoscope for trajectory corrections. TD2K is an improved version of the TIGER instrument flown in 1997, results from which are reported at this conference (Sposato et al., 1999). We will present the status of the TD2K instrument and of the ULDB program as it affects the Demo 2000 flight.