| タイトル | Spectra and angular distributions of atmospheric gamma rays from 0.3 to 10 MeV at lambda = 40 deg |
| 著者（英） | Ling, J. C.; Gruber, D. E. |
| 著者所属（英） | Jet Propulsion Lab., California Inst. of Tech.|California Univ. |
| 発行日 | 1977-03-01 |
| 言語 | eng |
| 内容記述 | Measurements of the spectral and angular distributions of atmospheric gamma sq cm rays in the energy range 0.3-10 MeV over Palestine, Texas, at residual depths of 2.5 and 70 g/sq cm are reported. In confirmation of the general features of a model prediction, the measurements show at 2.5 g/sq cm upward moving fluxes greater than the downward moving fluxes, the effect increasing with energy, and approximate isotropy at 70 g/sq cm. Numerous characteristic gamma-ray lines were observed, most prominently at 0.511, 1.6, 2.3, 4.4, and 6.1 MeV. Their intensities were also compared with model predictions. Observations were made with an actively shielded scintillator counter with two detectors, one of aperture 50 deg FWHM and the other of 120 deg FWHM. Above 1 MeV, contributions to the counting rate from photons penetrating the shield annulus and from neutron interactions were large; they were studied by means of a Monte Carlo code and are extensively discussed. |
| NASA分類 | GEOPHYSICS |
| レポートNO | 77A27329 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/438676 |
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