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Journal Articles

Strong lattice anharmonicity exhibited by the high-energy optical phonons in thermoelectric material

Wu, P.*; Fan, F.-R.*; Hagihara, Masato*; Kofu, Maiko; Peng, K.*; Ishikawa, Yoshihisa*; Lee, S.*; Honda, Takashi*; Yonemura, Masao*; Ikeda, Kazutaka*; et al.

New Journal of Physics (Internet), 22(8), p.083083_1 - 083083_9, 2020/08

 Times Cited Count:2 Percentile:51.78(Physics, Multidisciplinary)

Thermoelectric material SnSe has aroused world-wide interests in the past years, and its inherent strong lattice anharmonicity is regarded as a crucial factor for its outstanding thermoelectric performance. However, the understanding of lattice anharmonicity in SnSe system remains inadequate, especially regarding how phonon dynamics are affected by this behavior. In this work, we present a comprehensive study of lattice dynamics on Na$$_{0.003}$$Sn$$_{0.997}$$Se$$_{0.9}$$S$$_{0.1}$$ by means of neutron total scattering, inelastic neutron scattering, Raman spectroscopy as well as frozen-phonon calculations. Lattice anharmonicity is evidenced by pair distribution function, inelastic neutron scattering and Raman measurements. By separating the effects of thermal expansion and multi-phonon scattering, we found that the latter is very significant in high-energy optical phonon modes. The strong temperature-dependence of these phonon modes indicate the anharmonicity in this system. Moreover, our data reveals that the linewidths of high-energy optical phonons become broadened with mild doping of sulfur. Our studies suggest that the thermoelectric performance of SnSe could be further enhanced by reducing the contributions of high-energy optical phonon modes to the lattice thermal conductivity via phonon engineering.

Journal Articles

Effects of pre-crack depth and hydrogen absorption on the failure strain of Zircaloy-4 cladding tubes under biaxial strain conditions

Li, F.; Mihara, Takeshi; Udagawa, Yutaka; Amaya, Masaki

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 7 Pages, 2020/08

Journal Articles

Fracture-mechanics-based evaluation of failure limit on pre-cracked and hydrided Zircaloy-4 cladding tube under biaxial stress states

Li, F.; Mihara, Takeshi; Udagawa, Yutaka; Amaya, Masaki

Journal of Nuclear Science and Technology, 57(6), p.633 - 645, 2020/06

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

Journal Articles

New excited 2$$^+$$ and 3$$^-$$ two-proton states in $$_{84}^{210}$$Po$$_{126}$$ populated by two-proton transfer

Dupont, E.*; Astier, A.*; Petrache, C. M.*; Lv, B. F.*; Deloncle, I.*; Kiener, J.*; Orlandi, R.; Makii, Hiroyuki; Nishio, Katsuhisa; Hirose, Kentaro; et al.

Physical Review C, 101(1), p.014309_1 - 014309_6, 2020/01

 Times Cited Count:0 Percentile:0.02(Physics, Nuclear)

Journal Articles

The effect of hydride morphology on the failure strain of stress-relieved Zircaloy-4 cladding with an outer surface pre-crack under biaxial stress states

Li, F.; Mihara, Takeshi; Udagawa, Yutaka; Amaya, Masaki

Journal of Nuclear Science and Technology, 56(5), p.432 - 439, 2019/05

 Times Cited Count:4 Percentile:68.11(Nuclear Science & Technology)

Journal Articles

ASTRID nuclear island design; Update in French-Japanese joint team development of decay heat removal systems

Hourcade, E.*; Mihara, Takatsugu; Dauphin, A.*; Dirat, J.-F.*; Ide, Akihiro*

Proceedings of 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) (CD-ROM), p.556 - 561, 2018/04

In the framework of the French-Japanese agreement signed in 2014, CEA, AREVA NP, JAEA, and MHI/MFBR is jointly performing components design of ASTRID such as Decay Heat Removal Systems (DHRS). This paper is giving an update concerning ASTRID DHR strategy with description of reference architecture evolution and project objectives. In particular, new developments were made for DHR during normal shutdown and role of Ex-Vessel system. A special focus is made on design process of automatic shutter to hydraulically connect Hot Plenum and cold plenum to enhance primary vessel natural convection.

Journal Articles

Biaxial-EDC test attempts with pre-cracked zircaloy-4 cladding tubes

Li, F.; Mihara, Takeshi; Udagawa, Yutaka; Amaya, Masaki

Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 6 Pages, 2017/07

Journal Articles

Beam commissioning of the linac for iBNCT

Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11

The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.

Journal Articles

ASTRID nuclear island design; Advances in French-Japanese joint team development of decay heat removal systems

Hourcade, E.*; Curnier, F.*; Mihara, Takatsugu; Farges, B.*; Dirat, J.-F.*; Ide, Akihiro*

Proceedings of 2016 International Congress on Advances in Nuclear Power Plants (ICAPP 2016) (CD-ROM), p.1740 - 1745, 2016/04

In the framework of the French-Japanese agreement signed in 2014, CEA, AREVA NP, JAEA, and MHI/MFBR is jointly performing components design of ASTRID such as Decay Heat Removal Systems (DHRS). This paper is giving highlights of ASTRID DHRS current strategy. Focus is made on operating temperature diversification for in-vessel heat exchanger as well as core catcher coolability by an original features such as heat exchanger located within reactor cold pool, whose design was taken over by Japan team since 2014.

Journal Articles

Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector

Okumura, Yoshikazu; Gobin, R.*; Knaster, J.*; Heidinger, R.*; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; et al.

Review of Scientific Instruments, 87(2), p.02A739_1 - 02A739_3, 2016/02

 Times Cited Count:7 Percentile:44.58(Instruments & Instrumentation)

IFMIF is an accelerator based neutron facility having two set of linear accelerators each producing 125mA/CW deuterium ion beams (250mA in total) at 40MeV. The LIPAc (Linear IFMIF Prototype Accelerator) being developed in the IFMIF-EVEDA project consists of an injector, a RFQ accelerator, and a part of superconducting Linac, whose target is to demonstrate 125mA/CW deuterium ion beam acceleration up to 9MeV. The injector has been developed in CEA Saclay and already demonstrated 140mA/100keV deuterium beam. The injector was disassembled and delivered to the International Fusion Energy Research Center (IFERC) in Rokkasho, Japan, and the commissioning has started after its reassembly 2014; the first beam production has been achieved in November 2014. Up to now, 100keV/120mA/CW hydrogen ion beam has been produced with a low beam emittance of 0.2 $$pi$$.mm.mrad (rms, normalized).

Journal Articles

Measurement of ion species in high current ECR H$$^+$$/D$$^+$$ ion source for IFMIF (International Fusion Materials Irradiation Facility)

Shinto, Katsuhiro; Sen$'e$e, F.*; Ayala, J.-M.*; Bolzon, B.*; Chauvin, N.*; Gobin, R.*; Ichimiya, Ryo; Ihara, Akira; Ikeda, Yukiharu; Kasugai, Atsushi; et al.

Review of Scientific Instruments, 87(2), p.02A727_1 - 02A727_3, 2016/02

 Times Cited Count:7 Percentile:44.58(Instruments & Instrumentation)

Journal Articles

Progress of the high current Prototype Accelerator for IFMIF/EVEDA

Okumura, Yoshikazu; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; Gobin, R.*; Harrault, F.*; Heidinger, R.*; et al.

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.203 - 205, 2015/09

Under the framework of Broader Approach (BA) agreement between Japan and Euratom, IFMIF/EVEDA project was launched in 2007 to validate the key technologies to realize IFMIF. The most crucial technology to realize IFMIF is two set of linear accelerator each producing 125mA/CW deuterium ion beams up to 40MeV. The prototype accelerator, whose target is 125mA/CW deuterium ion beam acceleration up to 9MeV, is being developed in International Fusion Research Energy Center (IFERC) in Rokkasho, Japan. The injector developed in CEA Saclay was delivered in Rokkasho in 2014, and is under commissioning. Up to now, 100keV/120mA/CW hydrogen ion beams and 100keV/90mA/CW duty deuterium ion beams are successfully produced with a low beam emittance of 0.21 $$pi$$.mm.mrad (rms, normalized). Delivery of RFQ components will start in 2015, followed by the installation of RF power supplies in 2015.

Journal Articles

Energy neutral phosphate fertilizer production using high temperature reactors; A Philippine case study

Haneklaus, N.*; Reyes, R.*; Lim, W. G.*; Tabora, E. U.*; Palattao, B. L.*; Petrache, C.*; Vargas, E. P.*; Kunitomi, Kazuhiko; Ohashi, Hirofumi; Sakaba, Nariaki; et al.

Philippine Journal of Science, 144(1), p.69 - 79, 2015/06

The Philippines may profit from extracting uranium (U) from phosphoric acid during fertilizer production in a way that the recovered U can be beneficiated and taken as raw material for nuclear reactor fuel. Used in a high temperature reactor (HTR) that provides electricity and/or process heat for fertilizer processing and U extraction, energy-neutral fertilizer production, an idea first proposed by Haneklaus et al., is possible. This paper presents a first case study of the concept regarding a representative phosphate fertilizer plant in the Philippines and exemplary HTR designs (HTR50S and GTHTR300C) developed by the Japan Atomic Energy Agency (JAEA). Three different arrangements (version I-III), ranging from basic electricity supply to overall power supply including on site hydrogen production for ammonia conversion, are introduced and discussed.

Journal Articles

Monte Carlo analysis of the long-lived fission product neutron capture rates at the Transmutation by Adiabatic Resonance Crossing (TARC) experiment

Ab$'a$nades, A.*; $'A$lvarez-Velarde, F.*; Gonz$'a$lez-Romero, E. M.*; Ismailov, K.*; Lafuente, A.*; Nishihara, Kenji; Saito, Masaki*; Stanculescu, A.*; Sugawara, Takanori

Nuclear Engineering and Design, 254, p.148 - 153, 2013/01

 Times Cited Count:1 Percentile:12.53(Nuclear Science & Technology)

The design of Accelerator Driven Systems (ADS) requires the development of simulation tools that are able to describe in a realistic way their nuclear performance and transmutation rate capability. In this publication, we present an evaluation of state of the art Monte Carlo design tools to assess their performance concerning transmutation of long-lived fission products. This work, performed under the umbrella of the International Atomic Energy Agency, analyses two important aspects for transmutation systems: moderation on Lead and neutron captures of $$^{99}$$Tc, $$^{127}$$I and $$^{129}$$I. The analysis of the results shows how shielding effects due to the resonances at epithermal energies of these nuclides affects strongly their transmutation rate. The results suggest that some research effort should be undertaken to improve the quality of Iodine nuclear data at epithermal and fast neutron energy to obtain a reliable transmutation estimation.

Journal Articles

Post-irradiation SEM study of ZrC-based TRISO coatings from the PYCASSO experiments

Hania, R.*; M$'e$nard, G.*; Aihara, Jun; Ueta, Shohei; Knol, S.*; De Jong, A.*; Van den Berg, F.*; Van Staveren, T.*; De Groot, S.*

Proceedings of 6th International Topical Meeting on High Temperature Reactor Technology (HTR 2012) (USB Flash Drive), 5 Pages, 2012/10

The PYCASSO irradiation experiments have been conducted to determine the effect of irradiation at high temperature on the properties of various coating materials of the coated fuel particle. One part of PYCASSO is to evaluate the advanced barrier material ZrC. Pyrocarbon (PyC) / ZrC-coated ZrO$$_{2}$$ and Al$$_{2}$$O$$_{3}$$ particles fabricated by JAEA were irradiated by HFR at 900 $$^{circ}$$C and 1,100 $$^{circ}$$C, at the same flux level up to approximately 2 dpa. Samples of irradiated and unirradiated particles are under investigation using an electron microscope, with the aim to identify irradiation effects and the influence of the heat treatment after the fabrication on the ZrC microstructure. Preliminary results of this SEM study indicate that whereas the heat treatment at 1,800 $$^{circ}$$C prior to irradiation induces significant grain growth near the ZrC edges, embrittling the ZrC layer and weakening the iPyC-ZrC interface, irradiation has no noticeable effect on microstructure and coating strength.

Journal Articles

Monte Carlo modelling for the ${it in vivo}$ lung monitoring of enriched uranium; Results of an international comparison

Broggio, D.*; Bento, J.*; Caldeira, M.*; Cardenas-Mendez, E.*; Farah, J.*; Fonseca, T.*; Konvalinka, C.*; Liu, L.*; Perez, B.*; Capello, K.*; et al.

Radiation Measurements, 47(7), p.492 - 500, 2012/07

 Times Cited Count:20 Percentile:85.18(Nuclear Science & Technology)

Journal Articles

Investigation of nuclear data accuracy for the accelerator-driven system with minor actinide fuel

Nishihara, Kenji; Sugawara, Takanori; Iwamoto, Hiroki; Alvarez Velarde, F.*; Rineiski, A.*

Proceedings of 11th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (Internet), p.315 - 327, 2012/00

Accuracy of nuclear data, especially for minor actinides (MAs), is important in neutronics design of advanced reactors for MA transmutation such as an Accelerator-Driven System (ADS). Authors introduce the results of a benchmark activity in the IAEA CRP that revealed a discrepancy among k-effectives by different nuclear data libraries is as large as 3% even for an initial criticality before burn-up. In order to reduce this uncertainty, Transmutation Physics Experimental Facility (TEF-P) with a significant amount of MA is being proposed in the J-PARC project. An expected reduction of the uncertainty of criticality, void reactivity and Doppler coefficient by the TEF-P was numerically evaluated using the cross-section adjustment procedure based on the JENDL3.3. The uncertainty would be reduced from 1.3% to 0.6% if experimental results of the TEF-P and other past critical experiments were utilized to adjust nuclear data.

Journal Articles

Verification of high-energy transport codes on the basis of activation data

Titarenko, Yu. E.*; Batyaev, V. F.*; Butko, M. A.*; Dikarev, D. V.*; Florya, S. N.*; Pavlov, K. V.*; Titarenko, A. Yu.*; Tikhonov, R. S.*; Zhivun, V. M.*; Ignatyuk, A. V.*; et al.

Physical Review C, 84(6), p.064612_1 - 064612_19, 2011/11

 Times Cited Count:19 Percentile:76.34(Physics, Nuclear)

Nuclide production cross sections measured at the Institute for Theoretical and Experimental Physics (ITEP) for the targets of $$^{rm nat}$$Cr, $$^{56}$$Fe, $$^{rm nat}$$Ni, $$^{93}$$Nb, $$^{181}$$Ta, $$^{rm nat}$$W, $$^{rm nat}$$Pb, and $$^{209}$$Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with a number of codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from the $$^{208}$$Pb target irradiated by 500-MeV protons are presented.

Journal Articles

Event structure and double helicity asymmetry in jet production from polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07

 Times Cited Count:25 Percentile:72.31(Astronomy & Astrophysics)

We report on the event structure and double helicity asymmetry ($$A_{LL}$$) of jet production in longitudinally polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured $$A_{LL}$$ = -0.0014 $$pm$$ 0.0037 at the lowest $$P_T$$ bin and -0.0181 $$pm$$ 0.0282 at the highest $$P_T$$ bin. The measured $$A_{LL}$$ is compared with the predictions that assume various $$Delta G(x)$$ distributions.

Journal Articles

Verification of high-energy transport codes on the basis of activation data

Titarenko, Yu. E.*; Batyaev, V. F.*; Butko, M. A.*; Dikarev, D. V.*; Florya, S. N.*; Pavlov, K. V.*; Titarenko, A. Yu.*; Tikhonov, R. S.*; Zhivun, V. M.*; Ignatyuk, A. V.*; et al.

LA-UR-11-02704, 31 Pages, 2011/06

Nuclide production cross sections measured at ITEP for the targets of $$^{nat}$$Cr, $$^{56}$$Fe,$$^{nat}$$Ni, $$^{93}$$Nb, $$^{181}$$Ta, $$^{nat}$$W, $$^{nat}$$Pb, $$^{209}$$Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the MCNPX (Bertini and ISABEL options), CEM03.02, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, and CASCADE.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Further improvements of all tested here codes are recommended.

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