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The dating of pre-exposure times of lunar rocks and soils
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Eugster, O. |
| Copyright Year | 1986 |
| Description | Xenon produced by fission of uranium, thorium and plutonium has repeatedly been observed in lunar rocks and soils. In two basaltic rocks and in two soils Xe was found originating from fission of U-235 induced by neutrons which are due to the interactions of cosmic ray particles with lunar matter. Two facts lead to this conclusion: (1) fission Xe is present in excess of that expected for the U, Th, and Pu concentrations and for the gas retention age of the samples; and (2) the Xe-134/Xe-136 ratio of excess fission Xe is close to 1.25 as expected for neutron induced fission of U-235. Information on the duration of the exposure to cosmic rays was obtained from the Kr-81-Kr systematics whereas the effective shielding conditions were derived from the depth sensitive cosmogenic ratio Xe-131/Xe-126. For the four samples the exposure to cosmic rays in the lunar regolith is described by a two stage exposure model. The history of the four samples was derived in terms of duration and shielding depth of the two stages. |
| File Size | 69096 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19860018553 |
| Archival Resource Key | ark:/13960/t0wq4vd0b |
| Language | English |
| Publisher Date | 1986-01-01 |
| Access Restriction | Open |
| Subject Keyword | Lunar And Planetary Exploration Geochronology Fission Products Radiation Shielding Lunar Soil Regolith Xenon Isotopes Solar Wind Radiation Dosage Cosmic Rays Lunar Rocks Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
