Measurement of the Relative Abundances of the Ultra-Heavy Galactic Cosmic-Rays ($30 \leq Z \leq 40$) at the Top of the Atmosphere with TIGER

Observations of Ultra-Heavy (UH) galactic cosmic rays (GCR) help to distinguish the possible origins of GCRs. The Trans-Iron Galactic Element Recorder (TIGER) is designed to measure the charge ($Z$) and energy of GCRs using a combination of four scintillation counters, two Cherenkov counters, and a scintillating fiber hodoscope. TIGER has accumulated data on two successful flights from McMurdo, Antarctica: the first launched in December of 2001 with a total flight duration of 31.8 days and the second in December of 2003 with a total flight duration of 18 days. The two flights of TIGER achieved sufficient statistics and charge resolution to resolve $\sim$140 particles with $Z>30$, and have provided the best measurements to date for $_{30}$Zn, $_{31}$Ga, $_{32}$Ge, and $_{34}$Se. We present the relative abundances of the UH-GCRs as measured by TIGER and as propagated to the top of the atmosphere. These abundances are compared with GCR source models.