Physics NotePublished
Nuclear Tracks, Sm Isotopes and Neutron Capture Effects in the Elephant Morraine Shergottite
R.S. Rajan; G. Lugmair; A.S. Tamhane; G. Poupeau
1985
Publication details
- Authors
- R.S. Rajan; G. Lugmair; A.S. Tamhane; G. Poupeau
- Type
- Physics Note
- Status
- Published
- Publication date
- 1985
- Description
- Nuclear track studies, uranium concentration measurements and Sm-isotope studies have been performed on both lithologies A and B of the Elephant Morraine Shergottite, EETA 79001 Track studies show that EETA 79001 was a rather small object in space with a preatmospheric radius of 12 <math>\pm</math> 2 cm,.corresponding to a preatmospheric mass of 28 <math>\pm</math> 13 kg. U-concentrations measurements indicate that phosphates have concentrations ranging from 0.3 to 1.3 ppm. There are occasional phosphates with excess fission tracks:, possibly produced from neutron induced fission of U and Th. during the regolith exposure in the shergottite parent body (SPB). Sm-isotope studies, while not showing any clear cut excess in <math>^{150}Sm</math>, enable us to derive meaningful upper limits to thermal neutron fluences of 2 to <math>3 \times 10^{15}n/cm^2\,\!</math> , during a possible regolith irradiation. 'These limits are consistent writh.that required to explain the track data and also enable us to derive an upper limit to the neutron exposure age of EETA 79001. of 55 Myr in the SPB regolith.
- Year
- 1985
- Number
- CBPF-NF-083/85
- Linked to a thesis
- No
- Linked to a grant
- No