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.

Change in properties of superconducting magnet materials by fusion neutron irradiation

Nishimura, Arata*; Nishijima, Shigehiro*; Takeuchi, Takao*; Nishitani, Takeo

Fusion Engineering and Design, 82(5-14), p.1555 - 1560, 2007/10

https://doi.org/10.1016/j.fusengdes.2007.03.053

Recent researches on fusion reactor show neutron streaming from ports to outside of plasma vacuum vessels and neutron penetration through blanket and a neutron shielding structure. Therefore, superconducting magnet system in a fusion reactor will be irradiated by high energy particles. To evaluate the irradiation effect of fusion neutron on the superconducting magnet materials, a cryo-target system was constructed and installed at FNS/JAEA. The NbSn, NbAl samples and copper wires were cooled down to 4.5 K by a GM refrigerator and irradiation tests by 14 MeV neutron at cryogenic temperature were carried out. Change in electric resistance and critical temperatures were measured after irradiation. On the outside of the cryostat, GFRP and other sensors were arranged and irradiated at the same time. After the irradiation, the properties of those materials were investigated and the difference was discussed.

Internally Cu-stabilized RHQT NbAl superconductors with Ta matrix

Takeuchi, Takao*; Tagawa, Kohei*; Noda, Tetsuji*; Banno, Nobuya*; Iijima, Yasuo*; Kikuchi, Akihiro*; Kitaguchi, Hitoshi*; Kosuge, Michio*; Tsuchiya, Kiyosumi*; Koizumi, Norikiyo; et al.

IEEE Transactions on Applied Superconductivity, 16(2), p.1257 - 1260, 2006/06

https://doi.org/10.1109/TASC.2006.870804

Next generation nuclear fusion magnets would require a high-current conductor in fields more than 16 T. A CIC conductor of the rapid RHQT processed NbAl may be a promising candidate. Good deformability of intermediately-formed bcc supersaturated-solid solution indeed allowed fabricating such a CIC conductor, which would be subsequently transformation annealed. Ag has been internally included as a basic constituent of a round strand so far, because Ag is almost non-reactive with Nb matrix during the RHQ. However, both of Ag and Nb are not suitable nuclei from the viewpoint of radioactivity when irradiated with neutrons. Recently, we have succeeded in replacing the Nb matrix with Ta that has the advantage of shorter half-life of radioactivity. In the present study, an attempt has been made to replace the Ag internal stabilizer with Cu, in the aim of further reducing radioactivity, based on anticipation that Ta would be less reactive with Cu than Nb did.

Irradiation effect of 14 MeV neutron on interlaminar shear strength of glass fiber reinforced plastics

Nishimura, Arata*; Hishinuma, Yoshimitsu*; Seo, Kazutaka*; Tanaka, Teruya*; Muroga, Takeo*; Nishijima, Shigehiro*; Katagiri, Kazumune*; Takeuchi, Takao*; Shindo, Yasuhide*; Ochiai, Kentaro; et al.

AIP Conference Proceedings 824, p.241 - 248, 2005/09

https://doi.org/10.1063/1.2192357

Design activity of International Thermonuclear Experimental Reactor clarifies intense neutron streaming from ports for neutral beam injectors. Energy spectrum of the streaming is very wide and 14 MeV neutron and ray are the typical radiations. Large amount of glass fiber reinforced plastics will be used in a superconducting magnet system as an electric insulation material and a support structure, for such organic material is easy to manufacture, and light and cheap. In this report, effects of 14 MeV neutron and ray irradiation on interlaminar shear strength and fracture mode are investigated using G-10CR small specimen of which configuration was proposed as a standard for evaluation of the interlaminar shear strength.

Development of advanced NbAl superconductors for a fusion demo plant

Koizumi, Norikiyo; Takeuchi, Takao*; Okuno, Kiyoshi

Proceedings of 20th IAEA Fusion Energy Conference (FEC 2004) (CD-ROM), 8 Pages, 2004/11

http://www-naweb.iaea.org/napc/physics/fec/fec2004/datasets/FT_P1-6.html

no abstracts in English

Investigation of Shielding Analysis Method for Fusion Reactors

; ; *; *; *; *; Shin, Kazuo*; *; *; *; et al.

JAERI-M 82-216, 67 Pages, 1983/01

JAERI-M-82-216.pdf:1.68MB

no abstracts in English

Examinations on axial-strain and wave-shaped deformation characteristics of transformed NbAl strand

Nabara, Yoshihiro; Nunoya, Yoshihiko; Matsui, Kunihiro; Hemmi, Tsutomu; Koizumi, Norikiyo; Isono, Takaaki; Uno, Yasuhiro*; Okui, Yoshio*; Oshikiri, Masayuki; Seo, Kazutaka; et al.

no journal, , 

no abstracts in English

Microscopic investigatioon of cross section of ITER NbSn conductor

Banno, Nobuya*; Takeuchi, Takao*; Koizumi, Norikiyo; Okuno, Kiyoshi

no journal, , 

no abstracts in English