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?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：14 Percentile：73.46(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 
35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.
Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09
Neutron devices such as neutron detectors, optical devices including supermirror devices and 
He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.
Fuji, Hiroyuki*; Aoki, So; Ishii, Tomohiro*; Sakai, Junichi*
Zairyo To Kankyo, 64(5), p.178 - 182, 2015/05
This study focused on a breakdown of passive film which is followed by rust staining, and the objective of this study was to clarify the effect of stability of passive film on the resistance of rust staining of stainless steels. Atomospheric exposure test was carried out for 12 months. In order to compare the stability of passive film, measurements of potential-decay curves, and potentiostatic polarization tests were performed in acidic aqueous chloride solution. As a result, rust area of austenitic stainless steel was higher than that of ferritic stainless steel. This order didn't follow the orders of pitting potentials and densities of inclusions on surface between specimens. On the contrary, the order of the resistance of rust staining of stainless steels followed the order of the stability of passive film. One of the reasons why the resistance of rust staining of austenitic stainless steel was worse than that of ferritic stainless steel was seemed that chloride more easily broke passive film on the surface of austenitic stainless and formed micro pits which become initiations of rust staining and increase density of stains.
Sakai, Hiroshi*; Enami, Kazuhiro*; Furuya, Takaaki*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*; Aoto, Tomohiro*; Hayashi, Kyohei*; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.1787 - 1789, 2014/07
Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor based on the measurement of the interference of light between the measurement target and the reference point. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2 K cooling with the resolution of 10 
m.
Sakai, Hiroshi*; Aoto, Tomohiro*; Enami, Kazuhiro*; Furuya, Takaaki*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*; Hayashi, Kyohei*; et al.
Proceedings of 16th International Conference on RF Superconductivity (SRF 2013) (Internet), p.291 - 296, 2014/02
Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2 K cooling with the resolution of 10 m.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
and additive in the most conservative concentration distributionOkuno, Hiroshi; Sato, Shohei; Sakai, Tomohiro*; Uchiyama, Gunzo
Journal of Nuclear Science and Technology, 45(11), p.1108 - 1115, 2008/11
Times Cited Count：2 Percentile：16.95(Nuclear Science & Technology)For nuclear criticality safety evaluation of blenders at the mixed uranium-plutonium oxide (MOX) fuel plant, non-uniformity distributions of powders in three chemical components, i.e., MOX, uranium-dioxide (UO) and zinc-stearate, which is a fuel additive, should be taken into account. The model blender considered in this article contained a mixture of 33 wt% PuO-enriched MOX, depleted UO and zinc-stearate in a shape of an upside-down truncated cone, which was surrounded by 30 cm-thick polyethylene. For a limitation of the number of calculation cases, the fissile plutonium mass of the mixture was fixed to 98 kg, and the total concentration of MOX and UO was fixed to 4.0 g/cm. The most conservative fuel distribution in the aspect of nuclear criticality safety under these constraints was calculated with a two-dimensional optimum fuel distribution code OPT-TWO, so that the importance distribution of MOX and that of zinc-stearate should be individually flattened by conserving the mass of each component. The OPT-TWO calculation was followed by criticality calculation performed with the MCNP code to obtain the neutron multiplication factor of the fuel in the optimum fuel distribution. The most conservative fuel distribution obtained in this research was typically depicted as a shell of zinc-stearate embedded into the central MOX region surrounded by the peripheral UO region. An increase in the neutron multiplication factor was found 25% at most; non-uniformity of plutonium enrichment concentration and that of zinc-stearate concentration contributed to it in almost equal and independent ways.
Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.
Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01
Times Cited Count：52 Percentile：71.15(Biochemistry & Molecular Biology)Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.
Sato, Shohei; Sakai, Tomohiro*; Okuno, Hiroshi
JAEA-Data/Code 2007-017, 40 Pages, 2007/08
JAEA-Data-Code-2007-017.pdf:4.8MB
OPT-TWO is a calculation code which calculates the optimum concentration distribution, i.e., the most conservative concentration distribution in the aspect of nuclear criticality safety, of MOX (mixed uranium and plutonium oxide) fuels in the two-dimensional system. To achieve the optimum concentration distribution, we apply the principle of flattened fuel importance distribution with which the fuel system has the highest reactivity. Based on this principle, OPT-TWO takes the following 3 calculation steps iteratively to achieve the optimum concentration distribution with flattened fuel importance: (1) the forward and adjoint neutron fluxes, and the neutron multiplication factor, with TWOTRAN code which is a two-dimensional neutron transport code based on the SN method, (2) the fuel importance, and (3) the quantity of the transferring fuel. In OPT-TWO, the components of MOX fuel are MOX powder, uranium dioxide powder and additive. This report describes the content of the calculation, the computational method, and the installation method of the OPT-TWO, and also describes the application method of the criticality calculation of OPT-TWO.
Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*
IEEE Transactions on Applied Superconductivity, 16(2), p.1358 - 1361, 2006/06
Times Cited Count：16 Percentile：60.87(Engineering, Electrical & Electronic)The injection bump system of the 3-GeV RCS in J-PARC consists of the pulse bending magnets for the injection bump orbit, which are four horizontal bending magnets (shift bump), four horizontal painting magnets (h-paint bump), and two vertical painting magnets (v-paint bump). In this paper, the design of the magnets and power supply of the injection bump system are reported.
Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Ueno, Tomoaki*; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*; Tounosu, Shigeki*; et al.
IEEE Transactions on Applied Superconductivity, 16(2), p.1366 - 1369, 2006/06
Times Cited Count：8 Percentile：43.72(Engineering, Electrical & Electronic)The injection system of the 3-GeV RCS in J-PARC is composed of four main orbit bump magnets (shift bump) to merge the injection beam with the circulating beam. The magnetic field design and the structural analysis of the shift bump magnets have been performed using 3D magnetic and mechanical codes. In this paper, the design of the bending magnets is reported.
Saha, P. K.; Noda, Fumiaki*; Irie, Yoshiro; Hotchi, Hideaki; Takayanagi, Tomohiro; Hayashi, Naoki; Machida, Shinji*; Sakai, Izumi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.3739 - 3741, 2005/00
The RCS(rapid cycling synchrotron) of J-PARC(Japan proton accelerator research complex) acts as an injector to the main ring as well as a high-power beam for the spallation neutron source at a repetition rate of 25 Hz, where at present the injection and the extraction beam energy are chosen to be 0.181 GeV and 3.0 GeV, respectively. The present work concerns on the present design and calculations for the injection-dump line of the RCS, which includes, (1) an accurate aperture list of all elements taking into account a wide range of the betatron tune, effect of changing injection modes, multiple trajectories of different particles after the charge-exchange foil(like H0 from the H- and H- beam itself)and (2) an accurate estimation of the uncontrolled beam losses especially from the H0-excited states, multiple coulomb scattering at the charge-exchange foil and also the lorentz stripping loss at the septum magnets so as to optimize them concerning mainly the radiation issues as well as for the hands-on maintenance.
Takayanagi, Tomohiro; Irie, Yoshiro; Kamiya, Junichiro; Watanabe, Masao; Watanabe, Yasuhiro; Ueno, Tomoaki*; Noda, Fumiaki*; Saha, P. K.; Sakai, Izumi*; Kawakubo, Toshimichi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1048 - 1050, 2005/00
The pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC has been designed. The injection system consists of the pulsed bending magnets, which are four horizontal bending magnets (shift bump) and four horizontal painting magnets (h-paint bump) for the injection bump orbit, and two vertical painting magnets (v-paint magnet). The injection beam energy and the extraction beam power are 400 MeV and 1 MW at 25 Hz repetition rate, respectively. The acceptance to include the injection beam, the painting beam and the circulating beam at the shift bump points is a 388 mm wide and a 242 mm high. The shift bump has been designed using a 3D magnetic analysis code, which accomplished less than 0.4 % field deviation under 0.26 T excitation level.
Oku, Takayuki; Suzuki, Junichi; Sasao, Hajime*; Adachi, Tomohiro*; Shinohara, Takenao*; Ikeda, Kazuaki*; Morishima, Takahiro*; Sakai, Kenji*; Kiyanagi, Yoshiaki*; Furusaka, Michihiro*; et al.
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.116 - 119, 2004/08
Times Cited Count：21 Percentile：77.76(Instruments & Instrumentation)As a neutron has a magnetic dipole moment, it is accelerated in a magnetic field gradient. Thus, we can control a neutron trajectory free from neutron beam attenuation and scattering using the magnetic field gradient. A sextupole magnetic field functions as a neutron focusing and defocusing lens depending on the neutron spin state. The neutron focusing effect was experimentally verified using a 6-piece permanent sextupole magnet. For the application in practical neutron scattering experiments, a sextupole magnet with a sufficiently large aperture accompanied with strong focusing power is demanded. Recently, a superconducting sextupole magnet, a Halbach-type permanent sextupole magnet and a sextupole pulse electro-magnet have been developed in a project of the development and application of neutron optics. These magnets will be dedicated to practical uses in neutron scattering experiments. In this paper, current status of the development of the magnetic neutron lenses is reported, and their application in the neutron scattering experiments is discussed.
Oku, Takayuki*; Sakai, Kenji*; Adachi, Tomohiro*; Ikeda, Kazuaki*; Shimizu, Hirohiko*; Maruyama, Ryuji*; Hino, Masahiro*; Tasaki, Seiji*; Kiyanagi, Yoshiaki*; Kamiyama, Takashi*; et al.
Physica B; Condensed Matter, 335(1-4), p.226 - 229, 2003/07
Times Cited Count：7 Percentile：39.31(Physics, Condensed Matter)no abstracts in English
Okuno, Hiroshi; Sakai, Tomohiro*
Nuclear Technology, 140(3), p.255 - 265, 2002/12
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)In order to facilitate discussions based on quantitative analysis about the end effect, which is often talked about in connection to burnup credit in criticality safety evaluation of spent fuel, we introduced in this paper a burnup importance function. This function shows the burnup effect on the reactivity as a function of the fuel position; an explicit expression of this function was derived according to the perturbation theory. The burnup importance function was applied to the Phase IIA benchmark model that was adopted by the OECD/NEA Expert Group on Burnup Credit Criticality Safety. The function clearly displayed that burnup importance of the end regions increases (1) as burnup, (2) as cooling time, (3) in consideration of burnup profile, and (4) in consideration of fission products.
Okuno, Hiroshi; Tonoike, Kotaro; Sakai, Tomohiro*
Proceedings of International Conference on the New Frontiers of Nuclear Technology; Reactor Physics, Safety and High-Performance Computing (PHYSOR 2002) (CD-ROM), 8 Pages, 2002/10
As the burnup proceeds, reactivity of fuel assemblies for light water reactors decreases by depletion of fissile nuclides, especially in the axially central region. In order to describe the importance of the end regions to the reactivity change, a burnup importance function was introduced as a weighting function to a local burnup variation contributed to a reactivity decrease. The function was applied to the OECD/NEA/BUC Phase II-A model and a simplified Phase II-C model. The application to Phase II-A model clearly showed that burnup importance of the end regions increases as burnup and/or cooling time increases. Comparison of the burnup importance function for different initial enrichments was examined. The application result to the simplified Phase II-C model showed that the burnup importance function was helpful to find the most reactive fuel burnup distribution under the conditions that the average fuel burnup was kept constant and the variations in the fuel burnup were within the maximum and minimum measured values.
and additive, 1; Background, formulation and calculation modelOkuno, Hiroshi; Sato, Shohei; Uchiyama, Gunzo; Sakai, Tomohiro*
no journal, ,
no abstracts in English
and additive, 2; Calculation code and results, and further investigationSato, Shohei; Okuno, Hiroshi; Uchiyama, Gunzo; Sakai, Tomohiro*
no journal, ,
no abstracts in English
-FeSi nanocrystals by Cu dopingHirata, Tomoaki*; Kagawa, Seiya*; Nagatsuyu, Tomohiro*; Shibahara, Kohei*; Iwamoto, Ryotaro*; Kawakubo, Yuki*; Noguchi, Masaya*; Mizuki, Tatsuya*; Narumi, Kazumasa; Sakai, Seiji; et al.
no journal, ,
no abstracts in English
