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Journal Articles

Theoretical study on resonant inelastic X-ray scattering in quasi-one-dimensional cuprates

Nomura, Takuji; Igarashi, Junichi*

Journal of the Physical Society of Japan, 73(7), p.1677 - 1680, 2004/07

https://doi.org/10.1143/JPSJ.73.1677

Times Cited Count：26 Percentile：73.56(Physics, Multidisciplinary)

We study theoretically the resonant inelastic X-ray scattering in quasi-one-dimensional insulating copper oxides, where the incident photon energy is tuned to the Cu1-4 absorption energy. Our attention is focused particularly on the strong momentum-transfer dependence of the spectral shape observed in recent experiments. We describe the antiferromagnetic ground state within the Hartree-Fock theory, and consider charge excitations from the ground state within the random phase approximation. By taking account of the electron correlation effects perturbatively, we obtain detailed momentum-transfer dependence of the spectra in a semiquantitative agreement with the experiments.

Journal Articles

Lifetime evaluation of graphite components for HTGRs

Oku, Tatsuo*; Ishihara, Masahiro

Nuclear Engineering and Design, 227(2), p.209 - 217, 2004/01

https://doi.org/10.1016/j.nucengdes.2003.10.001

Times Cited Count：32 Percentile：87.07(Nuclear Science & Technology)

The lifetime of graphite material and/or components has been discussed individually from different concepts, and sometimes gives confusion to material researchers as well as designers. The lifetime of graphite materials is determined based on the dimensional changes due to neutron irradiation, at which they return to their original dimensions after initially contracting. On the other hand, the lifetime of graphite components for HTGRs is defined based on a margin of the specified minimum ultimate strengths of the graphite to the stresses induced in the graphite components. As an example, the stresses induced in the graphite block for the HTTR were, then, compared with the limited stress value determined from the specified minimum ultimate strength, and the lifetime of the graphite component was evaluated and compared with that defined as dimensional changes. As a result, it was found that the lifetime of graphite components for HTGRs should be determined as the shorter one in the two lifetimes defined by the stress-strength relationship and by the dimensional changes.

Journal Articles