| タイトル | Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years |
| 著者（英） | Reedy, R. C. |
| 著者所属（英） | Los Alamos Scientific Lab. |
| 発行日 | 1980-01-01 |
| 言語 | eng |
| 内容記述 | The use of cosmogenic radionuclides in lunar materials as indicators of solar cosmic ray fluxes and thus solar activity over the past 10 million years is discussed. The nature of solar and galactic cosmic ray particles and their interactions with matter are reviewed, with particular emphasis on nuclide production by cosmic-ray-induced nuclear reactions. Evidence of galactic cosmic ray flux variations from measurements of radionuclide activities in meteorites is considered which has indicated changes of less than about 25-50% over the last few million years. Measurements of radionuclide activities in lunar materials which are used to determine solar cosmic ray fluxes are then examined together with direct proton measurements indicating variations in solar fluxes with different solar cycles. It is noted that whereas average solar proton fluxes determined for the last 1-10 million years from Al-26 and Mn-53 data show little variation and are similar to recent values, lunar C-14 and Kr-81 activities indicate average solar proton fluxes several times greater over the past 10,000 to 100,000 years. |
| NASA分類 | LUNAR AND PLANETARY EXPLORATION |
| レポートNO | 81A48827
LA-UR-80-928
CONF-7910123-4 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/414930 |
