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

Observations of Ultra-Heavy 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 scintillation counters, Cherenkov counters, and a scintillating fiber hodoscope. TIGER has accumulated data on two successful flights from McMurdo, Antarctica in December of 2001 and in December of 2003 with a total flight duration of $\sim$50 days. The combined TIGER dataset achieved sufficient statistics and charge resolution to resolve $\sim$140 particle with $Z>30$, and provides the measurements to date for $_{30}$Zn, $_{31}$Ga, $_{32}$Ge, and $_{34}$Se. We present the preliminary abundances of the Ultra-Heavy GCRs derived from the combined dataset propagated to the top of the atmosphere, and discuss the results in the context of previous measurements and different GCR source models.