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Journal Articles

Population of nuclides with Z$$ge$$98 in multi-nucleon transfer reactions of $$^{48}$$Ca+$$^{248}$$Cm

Devaraja, H. M.*; Heinz, S.*; Beliuskina, O.*; Hofmann, S.*; Hornung, C.*; M$"u$nzenberg, G.*; Ackermann, D.*; Gupta, M.*; Gambhir, Y. K.*; Henderson, R. A.*; et al.

European Physical Journal A, 55(2), p.25_1 - 25_9, 2019/02

 Times Cited Count:12 Percentile:76.6(Physics, Nuclear)

Journal Articles

Proton-induced activation cross section measurement for aluminum with proton energy range from 0.4 to 3 GeV at J-PARC

Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki

Journal of Nuclear Science and Technology, 55(8), p.955 - 961, 2018/08

 Times Cited Count:7 Percentile:45.59(Nuclear Science & Technology)

We have started an experimental program to measure activation cross sections systematically in the proton-induced spallation reaction in structural materials commonly used in high-intensity proton accelerator-based facilities, such as Japan Proton Accelerator Research Complex (J-PARC). As the first step of the program, aluminum (Al) was chosen to verify the adequacy of the measurement technique implemented in a J-PARC proton beam environment because data of Al have been relatively well studied both by experimental measurement and simulation. Activation cross sections of $$^{7}$$Be, $$^{22}$$Na, and $$^{24}$$Na in Al were measured at proton energy points from 0.4, 1.3, 2.2 to 3.0 GeV, which could be delivered smoothly from the synchrotron. The validity of experimental data has been verified by introducing an effective proton numbers determination procedure. We compared the measured data with existing experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by the Particle and Heavy Ion Transport code System (PHITS) code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (generalized evaporation model) being implemented in the PHITS code. We found that the calculations agreed with the experimental data by an upgraded PHITS code.

Journal Articles

Radiochemical study of the kinematics of multi-nucleon transfer reactions in $$^{48}$$Ca + $$^{248}$$Cm collisions 10% above the Coulomb barrier

G$"o$tz, M.*; G$"o$tz, S.*; Kratz, J. V.*; D$"u$llmann, Ch. E.*; Mokry, Ch.*; Runke, J.*; Th$"o$rle-Pospiech, P.*; Wiehl, N.*; Sch$"a$del, M.; Ballof, J.*; et al.

Nuclear Physics A, 961, p.1 - 21, 2017/05

 Times Cited Count:6 Percentile:46.71(Physics, Nuclear)

The kinematics of multi-nucleon transfer reactions in the $$^{48}$$Ca + $$^{248}$$Cm collisions were investigated using a stacked-foil technique and radiochemical separations. In previous studies, isotopic distributions of the products of below-target isotopes were found to be broader than those of above-target isotopes, which had been interpreted as larger contributions of strongly dumped collisions in the productions of below-target isotopes than above-target ones. However, in the present study, the average total kinetic energy loss (TKEL), and thus, the average excitation energies were determined for both below-target and above-target isotopes, and they were found to be similar. This contradicts the previous interpretation, and thus, a new interpretation has been proposed; highly excited above-target products are lost by fission.

JAEA Reports

Measurement of high-energy neutron fluxes and spectra around the J-PARC mercury spallation neutron target using multi-foil activation method

Kasugai, Yoshimi; Harada, Masahide; Kai, Tetsuya; Oi, Motoki; Meigo, Shinichiro; Maekawa, Fujio

JAEA-Data/Code 2015-033, 28 Pages, 2016/03

JAEA-Data-Code-2015-033.pdf:1.78MB

The high-energy neutron fluxes and spectra around the mercury spallation neutron source at MLF of J-PARC were measured by the multi-foil activation method. The threshold energies of neutron reactions utilized in this experiment covered from 0.1 to 50 MeV. The foil irradiation was carried out on the first beam-run of MLF from May 30th to 31th, 2008. After the irradiation, the induced radioactivity of each foil was measured using an HPGe detector, and the neutron-induced reaction-rate distribution around the mercury target was determined. Using these data, the high-energy neutron fluxes and spectra were deduced with unfolding method in which the neutron spectra calculated with PHITS code were used as the initial-guess spectra. By comparison between the initial and the unfolded spectra, it was shown that most of the calculation results, which had been the basis of the neutronics design of the MLF target assembly, were consistent with the experimental data within $$pm$$30%.

Journal Articles

Chemical reaction of lithium with room temperature atmosphere of various humidities

Furukawa, Tomohiro; Hirakawa, Yasushi; Kondo, Hiroo; Kanemura, Takuji; Wakai, Eiichi

Fusion Engineering and Design, 98-99, p.2138 - 2141, 2015/10

BB2014-0426.pdf:0.49MB

 Times Cited Count:6 Percentile:45.66(Nuclear Science & Technology)

In the International Fusion Materials Irradiation Facility (IFMIF), a back plate of the target assembly will be exchanged during the in-service period. During the works, the lithium components will react chemically with the surrounding atmosphere. In this research, the chemical reaction of lithium in air, oxygen and nitrogen containing variable humidity at room temperature has been investigated to estimate the chemical reaction during the exchange works.

Journal Articles

Mechanisms of oxygen reduction reactions for carbon alloy catalysts via first principles molecular dynamics

Ikeda, Takashi; Hou, Z.*; Chai, G.-L.*; Terakura, Kiyoyuki*

Hyomen Kagaku, 36(7), p.345 - 350, 2015/07

Carbon alloy catalysts (CACs) are one of promising candidates for platinum-substitute cathode catalysts for polymer electrolyte fuel cells. We have investigated possible mechanisms of oxygen reduction reactions (ORRs) for CACs via first-principles-based molecular dynamics simulations. In this contribution, we review possible ORRs at likely catalytic sites of CACs suggested from our simulations.

Journal Articles

Possible oxygen reduction reactions for graphene edges from first principles

Ikeda, Takashi; Hou, Z.*; Chai, G.-L.*; Terakura, Kiyoyuki*

Journal of Physical Chemistry C, 118(31), p.17616 - 17625, 2014/08

 Times Cited Count:51 Percentile:80.6(Chemistry, Physical)

N-doped carbon-based nanomaterials are attracting a great interest as promising Pt-free electrode catalysts for polymer electrolyte fuel cells (PEFCs). In this computational study, we demonstrate that N-doped graphene edges can exhibit enhanced catalytic activity toward oxygen reduction reactions by controlling their electron-donating and -withdrawing abilities, and basicity, resulting in higher selectivity of 4e$$^{-}$$ reduction via inner and outer sphere electron transfer at edges in acidic conditions, respectively. Our simulations also show that 2e$$^{-}$$ reduction occurs selectively in the presence of pyridinic N next to carbonyl O at zigzag edges. This study thus rationalizes the roles of doped N in graphenelike materials for oxygen reduction reactions.

Journal Articles

Corrections to the $$^{148}$$Nd method of evaluation of burnup for the PIE samples from Mihama-3 and Genkai-1 reactors

Suyama, Kenya; Mochizuki, Hiroki*

Annals of Nuclear Energy, 33(4), p.335 - 342, 2006/03

 Times Cited Count:8 Percentile:49.48(Nuclear Science & Technology)

The value of the burnup is one of the most important parameters of samples taken by post irradiation examination (PIE). In this study, concerning the PIE data from Mihama-3 and Genkai-1 PWRs, which were taken at the Japan Atomic Energy Research Institute, the burnup values of the PIE samples were re-evaluated and the PIE data are re-analyzed using SWAT and SWAT2 code systems with JENDL-3.3 library. This analysis concludes that the burnup values of samples from Mihama-3 and Genkai-1 PWRs should be corrected of 2-3%. The effect of re-evaluation of the burnup value on the neutron multiplication factor is approximately 1% for PIE samples having the burnup of larger than 30 GWd/t. Comparison between calculation results using a single pin cell model and an assembly model is carried out. Because the both results agreed within a few percents, we concluded that the single pin cell model is suitable for the analysis of PIE samples and the underestimation of plutonium isotopes does not result from the geometry model.

Journal Articles

Methods for tritium production rate measurement in design-oriented blanket experiments

Verzilov, Y. M.; Ochiai, Kentaro; Nishitani, Takeo

Fusion Science and Technology, 48(1), p.650 - 653, 2005/07

 Times Cited Count:7 Percentile:44.84(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

JAERI Tandem annual report 2003; April 1, 2003 - March 31, 2004

Department of Materials Science

JAERI-Review 2004-027, 131 Pages, 2004/12

JAERI-Review-2004-027.pdf:17.03MB

This report is research activities using Tandem Accelerator in Tokai during April 1st in 2003 to March 31st in 2004, and contains 42 reports of 7sections of (1) operation and developments of tandem accelerator, (2) nuclear structure, (3) nuclear reactions, (4) nuclear chemistry, (5) nuclear theory, (6) atomic physics and solid state physics, (7) radiation effect of materials, and also contains of publication lists, personnel for related activities and the cooperation research program between JAERI and universities, national research organizations and so on.

JAEA Reports

JAERI Tandem annual report 2002; April 1, 2002 - March 31, 2003

Department of Materials Science

JAERI-Review 2003-028, 173 Pages, 2003/11

JAERI-Review-2003-028.pdf:8.28MB

This annual report describes research activities which have been performed with the JAERI tandem accelerator from April 1, 2002 to March 31, 2003. Summary reports of 54 papers, and lists of publication, personnel and cooperative research with universities are contained.

JAEA Reports

Neutron data storage and retrieval system NESTOR2

Nakagawa, Tsuneo

JAERI-Data/Code 2003-016, 89 Pages, 2003/11

JAERI-Data-Code-2003-016.pdf:3.0MB

The data storage and retrieval system for neutron-induced reaction data NESTOR2 was developed. NESTOR2 was written in Fortran77, and can be used on workstations with UNIX and personal computers with Windows. Input data to NESTOR2 are those in EXFOR which are compiled and maintained under the international collaboration for nuclear data. By using the retrieval code, they can obtain lists of data index, numerical data and comment information and data files of numerical data. The present report explains the system and provides a user's manual of NESTOR2.

Journal Articles

Coupled-channels analysis of nucleon interaction data of $$^{28,30}$$Si up to 200 MeV based on the soft rotator model

Sun, W.*; Watanabe, Yukinobu*; Sukhovitskij, E.*; Iwamoto, Osamu; Chiba, Satoshi

Journal of Nuclear Science and Technology, 40(9), p.635 - 643, 2003/09

 Times Cited Count:10 Percentile:56.35(Nuclear Science & Technology)

A consistent analysis for nuclear level structure and nucleon scattering data up to 200 MeV were performed for sd-shell nuclei, $$^{28,30}$$Si, using a unified framework of soft-rotator model and coupled-channels approach. The soft-rotator model parameters and optical model parameters were derived. The calculations showed good agreement with experimental data for both collective level and nucleon interaction data -- neutron total cross sections, proton reaction cross sections, and nucleon scattering angular distributions.

Journal Articles

Radioactivity production around the surface of a cooling water pipe in a D-T fusion reactor by sequential charged particle reactions

Hori, Junichi; Maekawa, Fujio; Wada, Masayuki*; Ochiai, Kentaro; Yamauchi, Michinori*; Morimoto, Yuichi*; Terada, Yasuaki; Klix, A.; Nishitani, Takeo

Fusion Engineering and Design, 63-64, p.271 - 276, 2002/12

 Times Cited Count:2 Percentile:16.96(Nuclear Science & Technology)

In order to the waste management method and the safety design of future D-T fusion reactor, it is important to consider the radioactivity productions via not only primary neutron reactions but also sequential charged particle reactions (SCPR). Especially, on the surface of a coolant channel many recoiled protons are generated by the neutron irradiation with coolant water, so it is apprehensive that the undesirable radioactive nuclide production yields via SCPR are enhanced. In this work, the laminated sample pieces of fusion material foils (V, Fe, W, Ti, Pb, Cu) were made and attached on a polyethylene board to simulate water flowing inside a coolant channel. They were irradiated with D-T neutrons. The effective radioactivity cross section and the depth distribution of the radioactivity production yields due to SCPR were obtained for each material. On the other hand, the estimated values were compared with the experimental ones.

JAEA Reports

Proceedings of the Workshop on Applications of IRFEL and Nuclear Isomers; Septemper 28, 2001, JAERI, Tokai, Japan

Yamauchi, Toshihiko; Hayakawa, Takehito; Shizuma, Toshiyuki

JAERI-Conf 2002-007, 54 Pages, 2002/08

JAERI-Conf-2002-007.pdf:5.32MB

The workshop on application of free-electron laser (FEL) and nuclear isomer study was held at Tokai Research Establishment of JAERI on September 28. The workshop was devoted to the discussions and the presentations of two thema as follows: Six papers associated with the laser compton gamma-ray, the photonuclear physics and the nuclear astrophysics using the gannma-ray produced by the T3 laser were presented in the morning session. Seven papers including an invited talk on the behavior of molecules in intense laser light fields and associated with the chemical decomposition of dioxin, the silicon isotope separetion, the infrared photoexcitation spectroscopy, the laser-tissue interaction and the single-wall carbon nanotube and nanohorn by FEL etc. were also presented in the afternoon session. The intensive discussion was exchanged among approximately 50 participants. Each performance during the first workshop was fully telecomunicated by a video conference system between Tokai and Kizu (Kansai Research Establishment) sites.

Journal Articles

Distribution behavior of plutonium and americium in LiCl-KCl eutectic/liquid cadmium systems

Sakamura, Yoshiharu*; Shirai, Osamu; Iwai, Takashi; Suzuki, Yasufumi

Journal of Alloys and Compounds, 321(1), p.76 - 83, 2001/05

 Times Cited Count:57 Percentile:89.48(Chemistry, Physical)

no abstracts in English

JAEA Reports

Thermal and chemical analysis of carbon dioxide reforming of methane using the out-of-pile test facility

Huang, Z.*; Ohashi, Hirofumi; Inagaki, Yoshiyuki

JAERI-Tech 2000-022, p.30 - 0, 2000/03

JAERI-Tech-2000-022.pdf:1.24MB

no abstracts in English

JAEA Reports

Measurement and theoretical analysis of neutron-induced neutron-emission reactions of $$^{6}$$Li at 10 to 20MeV region

*; *; Matsuyama, Shigeo*; Chiba, Satoshi; *; Shibata, Keiichi; Iwamoto, Osamu; A.J.Koning*; G.M.Hale*; M.B.Chadwick*

JAERI-Research 98-032, 28 Pages, 1998/06

JAERI-Research-98-032.pdf:1.31MB

no abstracts in English

Journal Articles

Measurements of the response function and the detection efficiency of an NE213 scintillator for neutrons between 20 and 65 MeV

Meigo, Shinichiro

Nuclear Instruments and Methods in Physics Research A, 401, p.365 - 378, 1997/00

 Times Cited Count:60 Percentile:95.92(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Analysis on evolving environments of engineered barriers of high-level radioactive waste repositories during the first 1,000 years

*; *; *; *; *; *; ; Nagasaki, Shinya*

Nihon Genshiryoku Gakkai-Shi, 35(5), p.420 - 437, 1993/05

 Times Cited Count:6 Percentile:55.97(Nuclear Science & Technology)

no abstracts in English

45 (Records 1-20 displayed on this page)