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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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New coolants, new fuels: A new generation of university reactors
Here’s an easy way to make aging U.S. power reactors look relatively youthful: Compare them (average age: 43) with the nation’s university research reactors. The 25 operating today have been licensed for an average of about 58 years.
Hiroshi Takahashi
Nuclear Science and Engineering | Volume 37 | Number 2 | August 1969 | Pages 198-215
Technical Paper | doi.org/10.13182/NSE69-A20679
Articles are hosted by Taylor and Francis Online.
The coherent neutron scattering from polycrystalline graphite is calculated using a sampling method with the Yoshimori-Kitano model and the Young-Koppel force constants. The calculations are compared with experimental results obtained by Carvalho, Eremeev et al., and Whittemore and it is shown that the agreement between the calculations and the experimental results is very good. For Carvalho's experiment, which corrects for multiple scattering, the agreement is good for the range of small momentum transfer (α) while for the experiments of Eremeev et al. the agreement is best for the range of intermediate α. A comparison of the dispersion relation, polarization vector and the dynamical structure factor for the Yoshimori-Kitano model and the Young-Koppel model indicates that the difference in the scattering laws is mainly due to the difference in the dispersion relations. A code called “ONE-PHONON” which uses a sampling method to calculate the scattering law is described. It is suggested that the measurement of the scattering law for each mode in pyrolitic graphite will give valuable information about the lattice dynamics of graphite.