Measurement of the Relative Abundances of the Ultra-Heavy Galactic Cosmic Rays (30 ≤ Z ≤ 40) with TIGER
Abstract
Observations of ultra-heavy (Z≥30) galactic cosmic rays (GCR) help to distinguish possible origins of GCR. The Trans-Iron Galactic Element Recorder (TIGER) measures the charge (Z) and energy of GCR using a combination of scintillators, Cherenkov detectors, and a scintillating fiber hodoscope. The two Cherenkov radiators, one acrylic and one aerogel, provide TIGER with an energy sensitivity between 0.3 and 10 GeV/nucleon in the instrument. The threshold at the top of the atmosphere is close to 0.8 GeV/nucleon for Fe. TIGER has accumulated data on two successful flights from McMurdo, Antarctica launched in D ecember 2001 and December 2003 with a total flight duration of 50 days. The combined dataset resolves ~140 nuclei with Z > 30, and provides the best measurements to date for 30Zn, 31Ga, 32Ge, and 34Se. The results for Ga and Ge taken together are inconsistent with a GCR source with Solar-System abundances modified either by preferential acceleration of elements of low first ionization potential or by preferential acceleration of refractory elements, suggesting that elemental composition of the GCR source is different from that of the Solar System
Additional Information
Copyright Universidad Nacional Autónoma de México This research was supported in part by a NASA grant, NNG05WC04G, and in part by Washington University. The success of these two balloon flights depended on the excellent support of the Columbia Scientific Balloon Facility, the NSF Office of Polar Programs, and the NASA Balloon Program OfficeAttached Files
Published - 2008-24.pdf
Files
Name | Size | Download all |
---|---|---|
md5:2b50295665bffe71084f27aa3bc0588b
|
1.8 MB | Preview Download |
Additional details
- Eprint ID
- 56634
- Resolver ID
- CaltechAUTHORS:20150414-113415014
- NNG05WC04G
- NASA
- Created
-
2015-04-21Created from EPrint's datestamp field
- Updated
-
2020-03-09Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 2008-24