Characteristic Fermi surface properties in -electron systems

Onuki, Yoshichika*; Settai, Rikio*; Haga, Yoshinori; Takeuchi, Tetsuya*; Hedo, Masato*; Nakama, Takao*

Quantum Science; The Frontier of Physics and Chemistry, p.21 - 63, 2022/10

https://doi.org/10.1007/978-981-19-4421-5_2

Quasi-one-dimensional magnetic interactions and conduction electrons in EuCu and EuAu with the characteristic hexagonal structure

Matsuda, Shinya*; Ota, Joji*; Nakaima, Kenri*; Iha, Wataru*; Gochi, Jun*; Uwatoko, Yoshiya*; Nakashima, Miho*; Amako, Yasushi*; Honda, Fuminori*; Aoki, Dai*; et al.

Philosophical Magazine, 100(10), p.1244 - 1257, 2020/04

https://doi.org/10.1080/14786435.2019.1708498

Single crystal growth and unique electronic states of cubic chiral EuPtSi and related compounds

Onuki, Yoshichika*; Kakihana, Masashi*; Iha, Wataru*; Nakaima, Kenri*; Aoki, Dai*; Nakamura, Ai*; Honda, Fuminori*; Nakashima, Miho*; Amako, Yasushi*; Gochi, Jun*; et al.

JPS Conference Proceedings (Internet), 29, p.012001_1 - 012001_9, 2020/02

https://doi.org/10.7566/JPSCP.29.012001

Fermi surface properties of semimetals YSb, LuSb, YBi, and LuBi studied by the de Haas-van Alphen effect

Kakihana, Masashi*; Nishimura, Kengo*; Takeuchi, Tetsuya*; Haga, Yoshinori; Harima, Hisatomo*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*

Journal of the Physical Society of Japan, 88(4), p.044712_1 - 044712_11, 2019/04

https://doi.org/10.7566/JPSJ.88.044712

Electronic states in EuCu(GeSi) based on the doniach phase diagram

Iha, Wataru*; Yara, Tomoyuki*; Ashitomi, Yosuke*; Kakihana, Masashi*; Takeuchi, Tetsuya*; Honda, Fuminori*; Nakamura, Ai*; Aoki, Dai*; Gochi, Jun*; Uwatoko, Yoshiya*; et al.

Journal of the Physical Society of Japan, 87(6), p.064706_1 - 064706_14, 2018/06

https://doi.org/10.7566/JPSJ.87.064706

Split Fermi surface properties in Ulmannite NiSbS and PdBiSe with the cubic chiral crystal structure

Kakihana, Masashi*; Teruya, Atsushi*; Nishimura, Kengo*; Nakamura, Ai*; Takeuchi, Tetsuya*; Haga, Yoshinori; Harima, Hisatomo*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika

Journal of the Physical Society of Japan, 84(9), p.094711_1 - 094711_8, 2015/09

https://doi.org/10.7566/JPSJ.84.094711

Fermi surface and magnetic properties of antiferromagnet EuBi

Nakamura, Ai*; Hiranaka, Yuichi*; Hedo, Masato*; Nakama, Takao*; Tatetsu, Yasutomi*; Maehira, Takahiro*; Miura, Yasunao*; Mori, Akinobu*; Tsutsumi, Hiroki*; Hirose, Yusuke*; et al.

Journal of the Physical Society of Japan, 82(12), p.124708_1 - 124708_6, 2013/12

https://doi.org/10.7566/JPSJ.82.124708

Stability test of RHQT NbAl cable-in-conduit conductor

Koizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Nakajima, Hideo; Takeuchi, Takao*; Banno, Nobuya*; Kikuchi, Akihiro*

Teion Kogaku, 46(8), p.495 - 499, 2011/08

https://doi.org/10.2221/jcsj.46.495

JAEA and NIMS has been collaborating in development of high performance Rapid-Heating-Quenching-Transformation (RHQT) NbAl CIC conductor, aiming at the application of this conductor to DEMO plant. The technical issue of the RHQT NbAl strand in the application to a fusion magnet is stabilization against perturbation. NIMS developed technique to attach copper stabilizer by using electroplating and a sub-scale CIC conductor is developed using this conductor. JAEA performed stability test of the developed CIC conductor to demonstrate efficiency of this copper stabilization technique. The measured stability margin is sufficiently high compared to the one of similar NbTi CIC conductor previously tested by the authors. Then, it can be concluded that the copper stabilizer works efficiently from view point of stability, resulting in solving the remained technical issues in the RHQT CIC conductor. Therefore, we can say that the RHQT NbAl CIC conductor is the most promising candidate for application to magnet in DEMO plant.

Fission neutron irradiation effect on interlaminar shear strength of cyanate ester resin GFRP at RT and 77 K

Nishimura, Arata*; Izumi, Yoshinobu*; Nishijima, Shigehiro*; Hemmi, Tsutomu; Koizumi, Norikiyo; Takeuchi, Takao*; Shikama, Tatsuo*

AIP Conference Proceedings 1219, p.127 - 134, 2010/04

https://doi.org/10.1063/1.3402293

A GFRP with cyanate ester resin was fabricated and neutron irradiation tests up to 110 n/m of fast neutron with over 0.1 MeV energy were carried out in fission reactor. The fabrication process of cyanate ester GFRP was established and a collaboration network to perform investigations on irradiation effect of superconducting magnet materials was constructed. Three kinds of samples were fabricated. The first was CTD403 GFRP made by NIFS, the second was (cyanate ester + epoxy) GFRP provided by Toshiba, and the last was CTD403 GFRP made by Toshiba. The irradiation was carried out at JRR-3 in Japan Atomic Energy Agency using Rabbit capsules. After the irradiation, short beam tests were conducted at room temperature and 77 K and interlaminar shear strength (ILSS) was evaluated. The irradiation of 110 n/m increased ILSS a little but 110 n/m irradiation decreased ILSS to around 50 MPa. These tendencies were observed in all three kinds of GFRPs.

Status and perspective of the NbAl development

Takeuchi, Takao*; Kikuchi, Akihiro*; Banno, Nobuya*; Kitaguchi, Hitoshi*; Iijima, Yasuo*; Tagawa, Kohei*; Nakagawa, Kazuhiko*; Tsuchiya, Kiyosumi*; Mitsuda, Shiori*; Koizumi, Norikiyo; et al.

Cryogenics, 48(7-8), p.371 - 380, 2008/07

https://doi.org/10.1016/j.cryogenics.2008.04.007

NbAl has advantages of better tolerance to strain/stress and a higher critical magnetic field (30 T at 4.2 K) for stoichiometric composition over NbSn. The rapid-heating, quenching and transformation annealing (RHQT) process enables to form a stoichiometric NbAl with fine grain structures via metastable bcc supersaturated-solid-solution. As a result a large critical current density of NbAl is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized NbAl strand is about be commercially available for NMR uses. Ag or Cu internal stabilization and Cu ion-plating/electroplating techniques have been also developed to enable the stabilized round wire for accelerator and fusion magnets. Successfully energized test coils that were manufactured with a wind-and-react technique have demonstrated that a long piece of Cu stabilized RHQT NbAl wire is really available for practical applications.