Abstract
We measured the concentrations of the cosmogenic radionuclides 10Be, 26Al, 36Cl and 41Ca in the metal and stone fractions of three large chondrite showers to determine their pre-atmospheric size. Large chondrites are characterized by substantial contributions of neutron-capture 41Ca in the stone fraction (up to ∼2 dpm/gCa), low radionuclide concentrations in the metal fraction and high 10Be(stone)/10Be(metal) ratios. Based on the measured concentrations in comparison with calculated cosmogenic nuclide depth profiles, using a semi-empirical and a purely physical model, we conclude that these objects had pre-atmospheric radii ranging from ∼80 cm to >3 m. We conclude that the semi-empirical model is more reliable for spallogenic production rates in large objects, while the purely physical model is more reliable for neutron-capture products.
Original language | English (US) |
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Pages (from-to) | 1185-1188 |
Number of pages | 4 |
Journal | Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms |
Volume | 268 |
Issue number | 7-8 |
DOIs | |
State | Published - Apr 2010 |
Externally published | Yes |
Keywords
- Chondrites
- Cosmogenic radionuclides
- Model calculations
- Pre-atmospheric size
- Production rates
ASJC Scopus subject areas
- Instrumentation
- Nuclear and High Energy Physics