Chemical binding effects in the thermalization of neutrons
- Creators
- Corngold, Noel
Abstract
In an earlier paper we extracted an asymptotic series solution in half-integral powers of (kTE) from the Boltzmann transport equation for neutrons coming into thermal equilibrium with a moderating material. In this paper we consider the series in detail for moderators having simple crystalline structure, or in which vibrational modes predominate, and give the coefficients of the series explicitly in terms of moments of the frequency spectrum of crystal vibrations. Our calculations indicate that the neutron density in the asymptotic region increases as one hardens the spectrum of crystal vibrations, whence the "hardness" of the neutron spectrum increases, too. We also discuss some aspects of the mass-expansion for these systems, and compare our calculations with those of other workers, and with typical experimental data for thermalization in water. Finally, we discuss the asymptotic expansion for moments of the scattering kernel and for ξσ_s, the slowing down power.
Additional Information
© 1960 Published by Elsevier Inc. Research carried out under the auspices of the U. S. Atomic Energy Commission. The author wishes to thank Mr. Bimal Malaviya for his assistance in the calculations of Appendix A, and Mr. Pradip Bakshi for the proof mentioned in Appendix B. He is also indebted to Dr. J. R. Beyster for a valuable discussion on the measurement of thermalization spectra and for the early communication of experimental results and to Dr. E. Melkonian for a valuable discussion of his cross-section measurements.Additional details
- Eprint ID
- 86552
- Resolver ID
- CaltechAUTHORS:20180522-133338347
- Atomic Energy Commission
- Created
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2018-05-24Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field