Excitation spectra and wave functions of quasiparticle bound states in bilayer Rashba superconductors

Higashi, Yoichi*; Nagai, Yuki; Yoshida, Tomohiro*; Kato, Masaru*; Yanase, Yoichi*

Physica C, 518, p.1 - 4, 2015/11

https://doi.org/10.1016/j.physc.2015.03.004

We study the excitation spectra and the wave functions of quasiparticle bound states at a vortex and an edge in bilayer Rashba superconductors under a magnetic field. In particular, we focus on the quasiparticle states at the zero energy in the pair- density wave state in a topologically non-trivial phase. We numerically demonstrate that the quasiparticle wave functions with zero energy are localized at both the edge and the vortex core if the magnetic field exceed the critical value.

Annual report of Nuclear Emergency Assistance and Training Center (April 1, 2013 - March 31, 2014)

Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.

JAEA-Review 2014-048, 69 Pages, 2015/02

JAEA-Review-2014-048.pdf:13.91MB

JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations

Quantum beam technology; Nanostructured proton-conductive membranes prepared by swift heavy ion irradiation for fuel cell applications

Yamaki, Tetsuya; Kobayashi, Misaki*; Asano, Masaharu; Nomura, Kumiko*; Takagi, Shigeharu*; Maekawa, Yasunari; Yoshida, Masaru*

Proceedings of Sadoway 60 Symposium, p.114 - 120, 2010/06

My presentation deals with the application of high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with hundreds of MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane.

Recent progress in the energy recovery linac project in Japan

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

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

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.

Preparation of PTFE-based fuel cell membranes by combining latent track formation technology with graft polymerization

Yoshida, Masaru*; Kimura, Yosuke*; Chen, J.; Asano, Masaharu; Maekawa, Yasunari

Radiation Physics and Chemistry, 78(12), p.1060 - 1066, 2009/12

https://doi.org/10.1016/j.radphyschem.2009.06.021

The swift heavy ions of 56 MeV Nwere irradiated with particle fluences of 3 10 ions/cm to form the latent track zone for a 25 m-thick film of polytetrafluoroethylene (iPTFE). The styrene (St) was grafted onto the iPTFE films by UV-irradiation and pre--irradiation and the resulting iPTFE-based proton conducting membranes were obtained after sulfonation, namely, iPTFE-g(UV)-PStSA and iPTFE-g()-PStSA membranes, which have a straight cylindrical damage zone around the ion path. The degree of grafting was obtained to be about 7.5% in both the UV-method and the -method. The ion exchange capacity, proton conductivity in thickness direction, MeOH permeability, tensile strength and elongation at break of the obtained iPTFE-g(UV)-PStSA membrane were 0.50 mmol/g, 0.06 S/cm, 0.15 10 cm/s, 50 MPa and 600%, in contrast to 0.06 mmol/g, 0.06 S/cm, 0.35 10 cm/s, 19 MPa and 210% for the iPTFE-g()-PStSA membrane, respectively. For comparison, the Nafion 112 measured in our laboratory showed an ion exchange capacity of 0.91 mmol/g, a proton conductivity of 0.06 S/cm, a MeOH permeability of 1.02 10 cm/s, a tensile strength of 35 MPa and an elongation at break of 295%. It could conclude from these data that the lower crossover of MeOH, proton conductibility of the Nafion corresponding even in lower ion exchange capacity and higher mechanical properties of the UV-grafted proton-conducting membranes make them promising materials for widespread application in direct methanol fuel cell.

Immobilization of functional materials onto poly(styrene--divinylbenzene) gels by irradiation and adsorption properties

Mishima, Satoko*; Asano, Masaharu; Yoshida, Masaru

Kobunshi Rombunshu, 66(7), p.250 - 258, 2009/07

https://doi.org/10.1295/koron.66.250

Pectin and triallylisocyanurate (TAIC) were immobilized onto poly(styrene--divinylbenzene) (PSD) beads by irradiating in the range of 2.5 to 25 kGy using -rays from a Co source. The adsorption performance of methyl-2-benzimidazolylcarbamate (MBC) treated with immobilized Pectin- TAIC beads was investigated. Pectin was effective to enhance the MBC uptakes at pH11, in contrast to pH3 for TAIC. The amounts of MBC uptake of immobilized Pectin-TAIC beads were 1.33.9 times higher than those of PSD beads which were only irradiated without the use of Pectin and TAIC in the range of pH3 to pH11. The cycles of absorption-desorption assays show that the sorption performance of immobilized Pectin-TAIC beads shows excellent reproducibility, suggesting that the immobilized Pectin-TAIC beads are a useful adsorbent for the extraction of MBC from environmental water.

Thermo- and pH-responsive poly(A-ProOMe)--poly (AAc) membrane for selective separation of metal ions

Hasegawa, Shin; Ohashi, Hitoshi; Maekawa, Yasunari; Katakai, Ryoichi*; Yoshida, Masaru

Polymer Journal, 41(7), p.533 - 540, 2009/07

https://doi.org/10.1295/polymj.PJ2007219

We investigated the permeation behavior of Li over Co and Ni ions through thermo- and pH-responsive gel membranes. The gel membranes were synthesized by -ray grafting of pH-responsive poly (acrylic acid) (AAc) onto a thermo-responsive polymer gel of acryloyl-L-proline methyl ester (A-ProOMe). The permeation constant of Li ions is 3.5 and 2.8 times higher than those of Co and Ni ions at 30 C in a pH 6.0. The most appropriate temperature and pH through the 15% grafted membrane were 30 C and pH 6.0. The adjacencies of the carboxyl groups of poly (AAc) surrounded by thermo-responsive poly (A-ProOMe) matrix must be decisive for the selective Li ion permeability. From the microscopic structures using SEM and the distributions of Co and Ni ions by EDS analysis, we confirmed that the structures formed by the flexible grafted chains of the carboxyl groups onto the thermo-response gel membrane are significant for the selective permeation of Li ion.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2005

Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.

JAEA-Review 2008-073, 99 Pages, 2009/03

JAEA-Review-2008-073-1.pdf:37.33MB
JAEA-Review-2008-073-2.pdf:37.16MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2005 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.

Hydrocarbon proton-conductive membranes prepared by radiation-grafting of styrenesulfonate onto aromatic polyamide films

Li, D.*; Chen, J.; Zhai, M.; Asano, Masaharu; Maekawa, Yasunari; Oku, Hiroyuki*; Yoshida, Masaru

Nuclear Instruments and Methods in Physics Research B, 267(1), p.103 - 107, 2009/01

https://doi.org/10.1016/j.nimb.2008.10.089

Novel method for preparing aromatic hydrocarbon proton-conductive membranes without sulfonation and membrane casting process is achieved by radiation grafting of sodium styrenesulfonate to an aromatic polyamide, poly(m-xylylene adipamide) (Nylon-MXD6) films and subsequent ion-exchange. The styrenesulfonate was easily grafted into the Nylon-MXD6 films from an oxygen-free dimethyl sulfoxide (DMSO) solution. As a result, the resulted styrenesulfonic acid-grafted Nylon-MXD6 films, namely proton-conductive membrane, with high ion exchange capacity up to 1.63 mmol/g, can be obtained. The membrane was transparent and highly hydrophilic. Furthermore, the methanol permeability was significantly lower than that of the Nafion membrane. Therefore, the Nylon-MXD6-based proton-conductive membrane is a more promising material for the direct methanol fuel cells (DMFCs).

Electron-beam-induced color imaging of acid-chromic polymer films

Maekawa, Yasunari; Yuasa, Kanako*; Enomoto, Kazuyuki; Matsushita, Harumi*; Kato, Jun*; Yamashita, Takashi*; Ito, Kazuo*; Yoshida, Masaru

Chemistry of Materials, 20(16), p.5320 - 5324, 2008/08

https://doi.org/10.1021/cm800650q

Polymer films with acid-responsive chromic dyes and acid generators have been designed for an electron beam (EB)-induced color imaging system. Arylsulfonic acid esters and triphenylsulfonium salts were used as an EB-sensitive acid generator; the acid (H) allows a chromic reaction with rhodamine B base (RB) and 4,4'-bis(dimethylamino)benzhydrol (BH) to be triggered. Upon EB irradiation, poly(methyl methacrylate) (PMMA) films consisting of RB or BH and acid generators exhibited a characteristic absorption band with max at 560 and at 612 nm, respectively, and an isosbestic point. These spectral changes clearly indicate that colorless chromic dyes in PMMA are transformed selectively to the colored form. The color imaging of these films was performed by electron beam direct writing (EBDW) with a 50 nm diameter beam to form 100 - 1000 nm line and space patterns and was evaluated by optical and confocal laser microscopy. EBDW on the acid chromic polymer films, especially for BH, yielded clear color imaging of 100 - 200 nm line and space patterns with a dose of only 10 C/cm. The confocal laser microscopy gave thinner lines than the laser wavelength (632.8 nm), probably because of the large change in refractive index of the patterned film induced by EB irradiation even with a low energy dose.