Trans-Iron Elemental and Isotopic Abundances from ACE/CRIS
Elements with nuclear charge Z>30 are very rare in both solar system and cosmic-ray material. As a result, their abundances are poorly known in cosmic rays because they require long exposure times with a large instrument. However, the abundances of Ultra-Heavy (UH) nuclei are of interest because they were synthesized by neutron-capture processes that occur very rapidly in core-collapse supernovae (r-process), and very slowly in Asymptotic Giant Branch (AGB) stars (s-process). The relative abundances of UH nuclei in cosmic rays provide constraints on the origin of galactic cosmic rays.
The Elemental and Isotopic composition of galactic cosmic rays with Atomic Number 29 <= Z <= 38 are presented in the following Astrophysical Journal paper:
Earlier Astrophysical Journal papers reporting galactic cosmic ray elemental and isotopic composition and spectra from ACE/CRIS include the following:
- Israel, M.H. et al, 2018, Elemental Composition at the Cosmic-Ray Source Derived from the ACE-CRIS Instrument. I. 6C to 28Ni
- Lave, K.A. et al, 2013, GALACTIC COSMIC-RAY ENERGY SPECTRA AND COMPOSITION DURING THE 2009-2010 SOLAR MINIMUM PERIOD
- George, J.S. et al, 2009, ELEMENTAL COMPOSITION AND ENERGY SPECTRA OF GALACTIC COSMIC RAYS DURING SOLAR CYCLE 23
- Yanasak, N.E. et al, 2001, Measurement of the Secondary Radionuclides 10Be, 26Al, 36Cl, 54Mn, and 14C and Implications for the Galactic Cosmic-Ray Age
- Wiedenbeck, M.E. et al, 1999, Constraints on the Time Delay between Nucleosynthesis and Cosmic-Ray Acceleration from Observations of 59Ni and 59Co
Preliminary measurements of Trans-Iron Elemental and Isotopic Abundances from ACE/CRIS were presented in two papers at the 32nd International Cosmic Ray Conference (ICRC), in Beijing (2011):
- Binns, W.R. et al, (2011), First Measurements of the Isotopic Composition of the Ultra-heavy Galactic Cosmic Ray Nuclei 31Ga and 32Ge from the CRIS Experiment on ACE
- Israel, M.H. et al, (2011), Measurements of the elemental abundances of ultra-heavy galactic cosmic rays from Cu through Sr from the CRIS experiment on the ACE satellite
- Summary of these two ICRC papers with links to figures
Galactic Cosmic Ray Isotopic Composition from CRIS of all elements from Li (Z=3) through Zn (Z=30) during a solar minimum period extending from December 1997 through September 1999.
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Last modified: Jan 2023