Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hashimoto, Shunsuke*; Nakajima, Kenji; Kikuchi, Tatsuya*; Kamazawa, Kazuya*; Shibata, Kaoru; Yamada, Takeshi*
Journal of Molecular Liquids, 342, p.117580_1 - 117580_8, 2021/11
Times Cited Count：3 Percentile：25.84(Chemistry, Physical)Quasi-elastic neutron scattering (QENS) and pulsed-field-gradient nuclear magnetic resonance (PFGNMR) analyses of a nanofluid composed of silicon dioxide (SiO
) nanoparticles and a base fluid of ethylene glycol aqueous solution were performed. The aim was to elucidate the mechanism increase in the thermal conductivity of the nanofluid above its theoretical value. The obtained experimental results indicate that SiO particles may decrease the self-diffusion coefficient of the liquid molecules in the ethylene glycol aqueous solution because of their highly restricted motion around these nanoparticles. At a constant temperature, the thermal conductivity increases as the self-diffusion coefficient of the liquid molecules decreases in the SiO nanofluids.
Seya, Michio; Kureta, Masatoshi; Soyama, Kazuhiko; Nakamura, Hironobu; Harada, Hideo; Hajima, Ryoichi
Proceedings of INMM 55th Annual Meeting (Internet), 10 Pages, 2014/07
JAEA has been implementing development programs of basic technologies of the following advanced NDA (non-destructive assay) of nuclear material (NM) for nuclear safeguards and security. (1) Alternative to 
He neutron detection using ZnS/BO
ceramic scintillator, (2) NRD (neutron resonance densitometry) using NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis), (3) NRF (nuclear resonance fluorescence)-NDA using laser Compton scattered (LCS) 
-rays (intense mono-energetic -rays). The development program (1) is for NDA systems that use ZnS/BO ceramic scintillator as alternative neutron detector to He for coming shortage of its supply. The program (2) is for a NDA system of isotopic composition measurement (non-destructive mass spectroscopy) in targets such as particle-like melted fuel debris using NRTA and NRCA. The program (3) is for NDA systems using a specific NRF reaction of certain Pu/U isotope caused by mono-energetic LCS -ray with energy tuned to the specific excited state of the isotope. This paper introduces above three programs.
Mori, K.; Namikawa, Kazumichi*; Koyama, Yasuki*; Ando, Masami*
Japanese Journal of Applied Physics, 32(Suppl.32-2), p.323 - 325, 1993/00
no abstracts in English
Kikuchi, Yasuyuki; *
Journal of Nuclear Science and Technology, 22(5), p.337 - 357, 1985/00
Times Cited Count：5 Percentile：59.78(Nuclear Science & Technology)no abstracts in English
Kikuchi, Yasuyuki; Nakagawa, Tsuneo; *; *; ; *
JAERI 1268, 142 Pages, 1981/02
no abstracts in English
Nakagawa, Masayuki
Journal of Nuclear Science and Technology, 16(12), p.891 - 896, 1979/00
Times Cited Count：0no abstracts in English
Tone, Tatsuzo
Journal of Nuclear Science and Technology, 6(1), p.43 - 44, 1969/00
no abstracts in English
UTone, Tatsuzo; ;
Journal of Nuclear Science and Technology, 4(12), p.601 - 606, 1967/00
Times Cited Count：2no abstracts in English
;
Journal of Nuclear Science and Technology, 2(3), p.91 - 98, 1965/00
no abstracts in English
-ray beamsSeya, Michio; Hajima, Ryoichi*; Hayakawa, Takehito*; Koizumi, Mitsuo
no journal, ,
The NRF-base NDA using monochromatic -rays would be used in nuclear security for secure detection of NM in thick shield and also for precise checking of interior structures of detected / suspicious objects. This NDA also would be used in nuclear safeguards for precise quantification of U/Pu isotopes in high radiation background, such as spent fuel assemblies / melted fuel debris in a canister. It is also useful for precise measurement of quantities of minor actinide isotopes in ADS (Accelerator Driven Sub-critical System; for transmutation of long-half-life minor actinides (MA)) fuels before and after irradiation in the ADS reactor core. In this presentation, we show actual NRF-NDA methods for these objects.
Hajima, Ryoichi; Seya, Michio
no journal, ,
The QST and the JAEA are proposing an ERL (energy recovery linac) -based Compton source to produce high flux photons (1013 ph/s) in MeV region with energy tenability for non-destructive assay (NDA) of all nuclides (including nuclear materials (NM)) utilizing nuclear resonant fluorescence (NRF). We can apply the proposed NDA system to nuclear security and nuclear safeguards for analyzing NM in severe conditions such as under very high radiation background or in deep inside material. For these applications we have studied NDA of isotopes in transmission geometry for measurement of NM inside a thick wall canister and in scattering geometry for measurement of NMs of spent fuel in water or detection of NM in a heavy shield. We present our efforts on these.
-raysOmer, M.; Shizuma, Toshiyuki*; Hajima, Ryoichi*; Angell, C.*
no journal, ,
An elastic scattering experiment has been performed using 100% linearly polarized -rays generated by laser Compton backscattering at Duke University, NC, USA. Photons of energy of 2 MeV elastically scattered off uranium target were measured with high-purity Ge detectors. The results are used in the simulation study to improve the sensitivity of identifying isotopes by nuclear resonance fluorescence. Validation of the elastic scattering cross section of a polarized -rays is reported.
Yamamoto, Akio*; Endo, Tomohiro*; Chiba, Go*; Tada, Kenichi
no journal, ,
The treatment of the resonance up-scattering effect for arbitrary nuclide is implemented in the nuclear data processing code FRENDY. The Mosteller benchmark is used to verify this new function. The fuel temperature coefficient differences between with and without consideration of the resonance up-scattering effect show good agreement with the previous study.
