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Problems encountered in the use of neutron methods for elemental analysis on planetary surfaces

Nuclear Instruments and Methods

By:
, , , , and
DOI: 10.1016/0029-554X(74)90289-4

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Abstract

From experimental studies of gamma rays from fast and thermal neutron reactions in hydrogeneous and non-hydrogeneous, semi-infinite samples and from Monte Carlo calculations on soil of a composition which might typically be encountered on planetary surfaces, it is found that gamma rays from fast or inelastic scattering reactions would dominate the observed spectra. With the exception of gamma rays formed by inelastically scattered neutrons on oxygen, useful spectra would be limited to energies below 3 MeV. Other experiments were performed which show that if a gamma-ray detector were placed within 6 m of an isotopic neutron source in a spacecraft, it would be rendered useless for gamma-ray spectrometry below 3 MeV because of internal activation produced by neutron exposure during space travel. Adequate shielding is not practicable because of the size and weight constraints for planetary missions. Thus, it is required that the source be turned off or removed to a safe distance during non-measurement periods. In view of these results an accelerator or an off-on isotopic source would be desirable for practical gamma-ray spectral analysis on planetary surfaces containing but minor amounts of hydrogen. ?? 1974.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Problems encountered in the use of neutron methods for elemental analysis on planetary surfaces
Series title:
Nuclear Instruments and Methods
DOI:
10.1016/0029-554X(74)90289-4
Volume
117
Issue:
2
Year Published:
1974
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Nuclear Instruments and Methods
First page:
435
Last page:
443
Number of Pages:
9