In-situ measurement of the rate of $sup 235$U fission induced by lunar neutrons
Journal Article
·
· Earth Planet. Sci. Lett., v. 21, no. 2, pp. 153-163
The depth proflle of the neutron-induced flssion rate of /sup 235/U was directly measured to a depth of 350 g/cm/sup 2/ by the Apollo 17 Lunar Neutron Probe Experiment. The fission rate rises sharply from the surface to a broad maximum from l10 to 160 g/cm/sup 2/ and drops off at greater depths. The shape of theoretical depth profile of Lingenfelter et al. fits the measured capture rates well at all depths. The absolute magnitude of the experimental fission rates is (11 plus or minus 17)% lower than those calculated theoretically. The excellent agreement between theory and experiment implies that conclusions drawn previously by interpreting lunar sample data with the theoretical capture rates will not require revision. In particular, lunar surface processes, rather than uncertainties in the capture nates, are required to explain the relatively low neutron fluences observed for surface soil samples compared to the fluences expected for a uniformly mixed regolith. (auth)
- Research Organization:
- California Inst. of Tech., Pasadena
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-29-025068
- OSTI ID:
- 4307312
- Journal Information:
- Earth Planet. Sci. Lett., v. 21, no. 2, pp. 153-163, Journal Name: Earth Planet. Sci. Lett., v. 21, no. 2, pp. 153-163; ISSN EPSLA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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