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C control rods in Fukushima Daiichi nuclear reactors during meltdown; B-Li isotopic signatures in cesium-rich microparticlesFueda, Kazuki*; Takami, Ryu*; Minomo, Kenta*; Morooka, Kazuya*; Horie, Kenji*; Takehara, Mami*; Yamasaki, Shinya*; Saito, Takumi*; Shiotsu, Hiroyuki; Onuki, Toshihiko*; et al.
Journal of Hazardous Materials, 428, p.128214_1 - 128214_10, 2022/04
Times Cited Count：6 Percentile：68.71(Engineering, Environmental)Saito, Shigeru; Obayashi, Hironari; Wan, T.; Okubo, Nariaki; Sugawara, Takanori; Endo, Shinya; Sasa, Toshinobu
Proceedings of 13th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '17) (Internet), p.448 - 457, 2018/05
JAEA proposes transmutation of minor actinides by accelerator-driven systems (ADS). To obtain the data for ADS design, JAEA plans to construct the ADS Target Test Facility (TEF-T) within the framework of the J-PARC project. In TEF-T, a 250 kW proton-beam-driven LBE (Lead-Bismuth Eutectic) spallation target will be installed to prepare an irradiation database for candidate ADS structural materials. Design activities of the LBE target and target trolley have been progressed. Conceptual design of hot-cells for LBE target loop maintenance and PIE (Post Irradiation Examination) of irradiated samples have been finished. Two LBE loops were manufactured. One is a loop for TEF-T target mock-up and the other is that for collection of material corrosion characteristics in flowing LBE. Oxygen potential control systems for LBE flow have been also developed. Remote handling tests for the target exchange are underway. In this paper, current activities and studies to realize TEF-T will be presented.
Nagasaki, Shinya*; Saito, Takumi; Yang, T.*
Journal of Radioanalytical and Nuclear Chemistry, 308(1), p.143 - 153, 2016/04
Times Cited Count：13 Percentile：77.16(Chemistry, Analytical)Sorption of Np(V) on illite, shale and MX-80 under oxidizing conditions were first studied in two types of high ionic strength solutions: (1) a reference brine solution (SR-270-PW) with an ionic strength (I) of 6.0 M, and (2) Na-Ca-Cl solutions (with different Na/Ca molar ratios and different ionic strengths, up to a maximum of 4.6 M). The effects of pHc, Na/Ca ratio, and ionic strength on sorption in Na-Ca-Cl solutions were investigated. The Kd values increased with increasing pHc and Na/Ca ratio for all sorbents studied. The Kd values on illite and shale were independent of the ionic strength over the range 0.10-4.6 M, and the Kd value on MX-80 was independent of ionic strength greater than 1.0 M. The Kd values and the sorption isotherms in both SR-270-PW and Na-Ca-Cl solutions were also studied.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Endo, Shinya; Sakuraba, Naotoshi; Miyai, Hiromitsu; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 450(1-3), p.27 - 31, 2014/07
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)no abstracts in English
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 431(1-3), p.44 - 51, 2012/12
Times Cited Count：2 Percentile：17.8(Materials Science, Multidisciplinary)To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS), post irradiation examination (PIE) of the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) specimens was carried out. The specimens tested in this study were made from the austenitic steel JPCA (Japan primary candidate alloy). The specimens were irradiated at SINQ Target 4 (STIP-II) with high-energy protons and spallation neutrons. The irradiation conditions were as follows: the proton energy was 580 MeV, irradiation temperatures ranged from 100 to 430
C, and displacement damage levels ranged from 7.1 to 19.5 dpa. Tensile tests were performed in air at room temperature (R.T.), 250C and 350C. Fracture surface observation after the tests was done by SEM (Scanning electron microscope). Results of the tensile tests performed at R.T. showed the extra hardening of JPCA at higher dose compared to the fission neutron irradiated data. At the higher temperatures, 250C and 350C, the extra hardening was not observed. Degradation of ductility bottomed around 10 dpa, and specimens kept their ductility until 19.5 dpa. All specimens fractured in ductile manner. The result from a microstructure observation on a specimen irradiated to 19.3 dpa at 420C indicates that some agglomeration of bubbles on grain boundaries was observed in the specimen irradiated to 19.3 dpa at 420C. However the tensile specimen irradiated up to 18.4 dpa at 425C still exhibited little loss of ductility. Since He/dpa was very high on SINQ target irradiations, the formation of highly dense small bubbles in the matrix consequently avoided the accumulation of He on grain boundaries, which might have resulted in avoiding grain boundary embrittlement.
Odaka, Hirokazu*; Ichinohe, Yuto*; Takeda, Shinichiro*; Fukuyama, Taro*; Hagino, Koichi*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; Watanabe, Shin*; Kokubun, Motohide*; et al.
Nuclear Instruments and Methods in Physics Research A, 695, p.179 - 183, 2012/12
Times Cited Count：23 Percentile：84.01(Instruments & Instrumentation)We have developed a new Si/CdTe semiconductor double-sided strip detector (DSD) Compton camera. The camera consists of a 500-
m-thick Si-DSD and four layers of 750-m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 degrees at 356 keV and 3.5 degrees at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.
-ray cameraTakeda, Shinichiro*; Ichinohe, Yuto*; Hagino, Koichi*; Odaka, Hirokazu*; Yuasa, Takayuki*; Ishikawa, Shinnosuke*; Fukuyama, Taro*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; et al.
Physics Procedia, 37, p.859 - 866, 2012/10
Times Cited Count：22 Percentile：98.43(Physics, Applied)By using new Compton camera consisting of silicon double-sided strip detector (Si-DSD) and CdTe-DSD developed for the ASTRO-H mission, an experiment was conducted to study its feasibility for advanced hotspot monitoring. In addition to hotspot imaging already provided by commercial imaging systems, the identification of the variety of radioisotopes is realized thanks to the good energy resolution given by the semiconductor detectors. Three radioisotopes of 
Ba (356 keV), 
Na (511 keV) and 
Cs (662 keV) were individually imaged by applying event selection in the energy window and the -ray images was correctly overlapped by an optical picture. The detection efficiency of 1.68
10
(effective area: 1.710 cm
) and angular resolution of 3.8 were obtained by stacking five detector modules for 662 keV -ray. The higher detection efficiency required in a specific use can be achieved by stacking more detector modules.
bound to humic substances by time-resolved laser fluorescence spectroscopy (TRLFS) and parallel factor analysis (PARAFAC)Lukman, S.*; Saito, Takumi*; Aoyagi, Noboru; Kimura, Takaumi; Nagasaki, Shinya*
Geochimica et Cosmochimica Acta, 88, p.199 - 215, 2012/07
Times Cited Count：24 Percentile：55.25(Geochemistry & Geophysics) adsorbed on kaolinite by time-resolved laser fluorescence spectroscopy (TRLFS) and parallel factor analysis (PARAFAC)Ishida, Keisuke*; Saito, Takumi*; Aoyagi, Noboru; Kimura, Takaumi; Nagaishi, Ryuji; Nagasaki, Shinya*; Tanaka, Satoru*
Journal of Colloid and Interface Science, 374(1), p.258 - 266, 2012/05
Times Cited Count：29 Percentile：56.9(Chemistry, Physical)Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Nuclear Instruments and Methods in Physics Research B, 272, p.49 - 52, 2012/02
Times Cited Count：9 Percentile：52.49(Instruments & Instrumentation)
collisions at 
= 200 GeVAdare, 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：29 Percentile：72.31(Astronomy & Astrophysics)We report on the event structure and double helicity asymmetry (
) of jet production in longitudinally polarized collisions at = 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 = -0.0014 
0.0037 at the lowest 
bin and -0.0181 0.0282 at the highest bin. The measured is compared with the predictions that assume various 
distributions.
collisions at = 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count：184 Percentile：99.44(Physics, Nuclear)Transverse momentum distributions and yields for 
, and 
in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as 
and 
scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Kosugi, Shinya*; Fujita, Naoki*; Matsui, Toshiyuki*; Hori, Fuminobu*; Saito, Yuichi; Ishikawa, Norito; Okamoto, Yoshihiro; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 269(9), p.869 - 872, 2011/05
Times Cited Count：10 Percentile：60.88(Instruments & Instrumentation)Effects of thermal annealing on ion-irradiation induced ferromagnetism of FeRh bulk alloy and the related structural change were investigated by means of superconducting quantum interference device (SQUID) and extended X-ray absorption fine structure (EXAFS), respectively. Depending on the annealing temperature from 100 to 500 C, the magnetization induced by 10 MeV iodine ion irradiation and the lattice structure of the alloy were remarkably changed. After 500 C annealing, the magnetization and the lattice ordering of the alloy become similar to the states before the irradiation. The experimental result indicates that the thermal relaxation of irradiation-induced atomic disordering dominates the magnetic state of ion-irradiated FeRh alloy.
Kosugi, Shinya*; Ishikawa, Norito; Saito, Yuichi; Hori, Fuminobu*; Iwase, Akihiro*
Journal of Nuclear Materials, 411(1-3), p.171 - 173, 2011/04
Times Cited Count：3 Percentile：26.02(Materials Science, Multidisciplinary)Changes in electrical resistivity induced by irradiation with energetic electrons were measured for Fe-50 at.%Rh alloy as a function of electron energy in the range from 0.5 to 2.0 MeV. The irradiation was carried out below 20 K and the resistivity was measured at 10 K. The electron energy dependence of the resistivity change rate was analysed by using a simple displacement theory, and the average threshold energies for atomic displacements, 
, were determined as 30 eV for Fe and 45 eV for Rh.
and Au+Au collisions at 
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count：8 Percentile：49.7(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
+ collisions at = 200 GeV and scaling properties of hadron productionAdare, 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, 83(5), p.052004_1 - 052004_26, 2011/03
Times Cited Count：175 Percentile：98.48(Astronomy & Astrophysics)The PHENIX experiment at RHIC has measured the invariant differential cross section for production of 
, 
, 
and 
mesons in collisions at = 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters, 
and 
, determining the high 
and characterizing the low regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Journal of Nuclear Materials, 408(2), p.201 - 204, 2011/01
Times Cited Count：13 Percentile：66.82(Materials Science, Multidisciplinary)Saito, Takumi*; Sao, Hirokazu*; Ishida, Keisuke*; Aoyagi, Noboru; Kimura, Takaumi; Nagasaki, Shinya*; Tanaka, Satoru*
Environmental Science & Technology, 44(13), p.5055 - 5060, 2010/07
Times Cited Count：33 Percentile：60.58(Engineering, Environmental)Fujita, Naoki*; Matsui, Toshiyuki*; Kosugi, Shinya*; Sato, Takahiro; Saito, Yuichi; Takano, Katsuyoshi; Koka, Masashi; Kamiya, Tomihiro; Seki, Shu*; Iwase, Akihiro*
Japanese Journal of Applied Physics, 49(6), p.060211_1 - 060211_3, 2010/06
Times Cited Count：12 Percentile：45.82(Physics, Applied)Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu; Endo, Shinya; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 398(1-3), p.49 - 58, 2010/03
Times Cited Count：6 Percentile：40.28(Materials Science, Multidisciplinary)In several institutes, R&D for an ADS have been progressed. Ferritic / martensitic (F/M) steels are the candidate material for the beam window. To obtain the irradiation data, the PIE work of the SINQ target irradiation program (STIP) specimens was carried out at JAEA. In this study, the results of PIE on F/M steel F82H and its welded joint will be reported. The results of tensile tests indicate that the irradiation hardening occurred with increasing dpa up to 10.1 dpa below 320C irradiation. At higher dose (- 11.8 dpa) and higher temperature (- 380C), irradiation hardening and degradation of ductility relaxed. In this study, all specimens kept its ductility after irradiation and fractured in ductile manner. The fatigue life of F82H base metal is almost the same as that of unirradiated specimens. Though the number of specimen is limited, the fatigue life of F82H EB welded joints seems to increase after irradiation. The fracture surfaces of the specimens showed transgranular morphology. While F82H TIG welded specimens were not fractured by 10
cycles.
