Detecting halfmetallic electronic structures of spintronic materials in a magnetic field

Fujiwara, Hidenori*; Umetsu, Rie*; Kuroda, Fumiaki*; Miyawaki, Jun*; Kashiuchi, Toshiyuki*; Nishimoto, Kohei*; Nagai, Kodai*; Sekiyama, Akira*; Irizawa, Akinori*; Takeda, Yukiharu; et al.

Scientific Reports (Internet), 11(1), p.18654_1 - 18654_9, 2021/09

https://doi.org/10.1038/s41598-021-97992-z

Quasifree neutron knockout reaction reveals a small -Orbital component in the Borromean nucleus B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

AA2020-0819.pdf:1.29MB

https://doi.org/10.1103/PhysRevLett.126.082501

A quasifree (,) experiment was performed to study the structure of the Borromean nucleus B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for and orbitals, and a surprisingly small percentage of 9(2)% was determined for . Our finding of such a small component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B. The present work gives the smallest - or -orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of or orbitals is not a prerequisite for the occurrence of a neutron halo.

Shell evolution beyond =28 and =50; Spectroscopy of Zn

Shand, C. M.*; Podolyk, Zs.*; Grska, M.*; Doornenbal, P.*; Obertelli, A.*; Nowacki, F.*; Otsuka, T.*; Sieja, K.*; Tostevin, J. A.*; Tsunoda, T.*; et al.

Physics Letters B, 773, p.492 - 497, 2017/10

https://doi.org/10.1016/j.physletb.2017.09.001

Magnetic patterning of FeRh thin films by energetic light ion microbeam irradiation

Koide, Tetsuya*; Sato, Takahiro; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro; Okochi, Takuo*; Kotsugi, Masato*; Kinoshita, Toyohiko*; Nakamura, Tetsuya*; Iwase, Akihiro*; et al.

Japanese Journal of Applied Physics, 53(5S1), p.05FC06_1 - 05FC06_4, 2014/05

https://doi.org/10.7567/JJAP.53.05FC06

We previously reported that the magnetic state of FeRh can be controlled by irradiation with ion beams. In this paper, we evaluate possibility of magnetic patterning on FeRh thin films using energetic light ion microbeam irradiation with various shapes and dimensions. Proton microbeam irradiation with 2 MeV was performed at JAEA-Takasaki to produce micron-sized magnetic patterns. XMCD-PEEM observation was performed at SPring8 to confirm the synthesized magnetic patterns. As a result, the XMCD-PEEM images of the various micrometer sized patters in FeRh film were observed using 2 MeV H ion beam. The observed bright regions are considered to have ferromagnetic spin orders, in contrast that the gray areas have anti-ferromagnetic spin order. Since the brightness of the PEEM images is strongly correlated with the magnetization of the samples, we reveal that the magnetic state in local regions of the FeRh thin films can be controlled by changing the ion fluences.

Mechanical properties of full austenitic welding joint at cryogenic temperature for the ITER toroidal field coil structure

Iguchi, Masahide; Saito, Toru; Kawano, Katsumi; Chida, Yutaka; Nakajima, Hideo; Ogawa, Tsuyoshi*; Katayama, Yoshinori*; Ogata, Hiroshige*; Minemura, Toshiyuki*; Tokai, Daisuke*; et al.

Fusion Engineering and Design, 88(9-10), p.2520 - 2524, 2013/10

https://doi.org/10.1016/j.fusengdes.2013.02.165

ITER TFC structures are large welding structures made of heavy thick stainless steels. JAEA plans to apply narrow gap TIG welding with FMYJJ1 which is full austenitic stainless filler material to manufacture TFC structure. FMYJJ1 is specified in "Codes for Fusion Facilities -Rules on Superconducting Magnet Structure (2008)". In order to evaluate effect of base material combinations and thickness of welded joint on tensile properties at 4 K, tensile tests were conducted at 4 K by using tensile specimens taken from 40 mm thickness weld joints of four combinations and 200 mm thickness ones of two combinations of base materials. These weld joints were manufactured by one side narrow gap TIG welding with FMYJJ1. As the results, it was confirmed that yield and tensile strengths of welded joint at 4K were decreased with decreasing of nitrogen of base material, and there were no large distribution of strengths at 4 K along the thickness of welded joints of 200 mm thickness.

Development of structures for ITER toroidal field coil in Japan

Iguchi, Masahide; Chida, Yutaka; Takano, Katsutoshi; Kawano, Katsumi; Saito, Toru; Nakajima, Hideo; Koizumi, Norikiyo; Minemura, Toshiyuki*; Ogata, Hiroshige*; Ogawa, Tsuyoshi*; et al.

IEEE Transactions on Applied Superconductivity, 22(3), p.4203305_1 - 4203305_5, 2012/06

https://doi.org/10.1109/TASC.2011.2177795

Japan Atomic Energy Agency (JAEA) has responsibility to procure 19 structures for ITER toroidal field (TF) coils as in-kind components. JAEA plans to use materials specified in the material section of "Codes for Fusion Facilities; Rules on Superconducting Magnet Structure (2008)" issued by the Japan Society of Mechanical Engineers (JSME) in 2008. Large forged products were produced and their mechanical properties at 4K were evaluated. In addition, the following activities have been performed; (1) to optimize the design of each weld type identified in the manufacturing sequence, (2) to qualify typical welding procedure including repair, (3) to establish welding techniques other than narrow gap TIG welding with FMYJJ1, (4) to demonstrate the manufacturing procedures through manufacture of 1-m mockups and full-scale segments of TFC structure. This paper describes the results of material qualification and industrialization activities of manufacturing processes of ITER TFC structure.

A Possible overestimation of the effect of acetylation on lysin residues in KQ mutant analysis

Fujimoto, Hirofumi*; Higuchi, Mariko; Koike, Manabu*; Ode, Hirotaka*; Pinak, M.; Kotulic Bunta, J.*; Nemoto, Toshiyuki*; Sakudo, Takashi*; Honda, Naoko*; Maekawa, Hideaki*; et al.

Journal of Computational Chemistry, 33(3), p.239 - 246, 2012/01

https://doi.org/10.1002/jcc.21956

Lysine acetylation is one of the most common protein post transcriptional modifications. The acetylation effects of lysine residues on Ku protein were examined herein applying several computer simulation techniques. Acetylation of the lysine residues did not reduce the affinity between Ku and its substrate, DNA, in spite of the fact that the substitution of lysine with glutamine (KQ mutant) reduced the affinity of Ku for DNA, or the substitution of lysine with arginine (KR mutant) did not reduce it, as previously reported in experimental studies. These results suggest that the effects of in vivo acetylation may be overestimated when the KQ mutant is employed in mimicry of the acetylated protein.

Relaxation behaviour of laser peening residual stress due to mechanical loading on aluminum alloy

Miyashita, Daisuke*; Takeda, Kazuya*; Oya, Shinichi*; Sano, Yuji*; Saito, Toshiyuki*; Akita, Koichi

Zairyo, 60(7), p.617 - 623, 2011/07

https://doi.org/10.2472/jsms.60.617

The surface residual stress relaxation under tensile loading occurred when the plastic-deformation started at the inside of material where the balancing tensile residual stress existed. Under the compressive loading, the surface residual stress relaxation started due to the plastic deformation beneath the surface where the maximum compressive residual stress existed. The plastic deformation at the inside of material caused the redistribution of the residual stress and resulted in the relaxation of the surface residual stress. For both tensile and compressive loading, the surface compressive residual stress relaxation occurred before the total stress (= (residual stress) + (applied stress)) at the surface reached to the yield condition. The conclusions of this study are thought to be able to apply to the behavior of the residual stress under the mechanical loading on metallic materials treated by any mechanical surface treatment.

Stability of residual stress induced by laser peening under cyclic mechanical loading

Sano, Yuji*; Akita, Koichi; Takeda, Kazuya*; Sumiya, Rie*; Tazawa, Toshiyuki*; Saito, Toshiyuki*; Narazaki, Chihiro*

International Journal of Structural Integrity, 2(1), p.42 - 50, 2011/01

https://doi.org/10.1108/17579861111108608

The purpose of this paper is to investigate the behavior of compressive residual stress induced by laser peening under external loading on an age-hardened high-strength aluminum alloy A2024-T3, a low-carbon austenitic stainless steel SUS316L (Type 316L) and a nickel-based alloy NCF600 (Alloy 600). The surface residual stress was measured intermittently by X-ray diffraction during cyclic uniaxial loading. The compressive residual stress due to laser peening significantly decreased during the first few cycles at stress ratio of 0.1 with the maximum loading stress exceeding the 0.2 per cent yield stress. Under symmetric loading at the stress ratio of -1 to A2024-T3, a major decrease took place in the compression side of the first loading cycle. The surface residual stresses remained in compression within all the extent of the present experiments, even if the maximum loading stress exceeded the yield stress of the materials.

Relaxation process of residual stress induced by laser peening

Akita, Koichi; Miyashita, Daisuke*; Takeda, Kazuya*; Oya, Shinichi*; Shobu, Takahisa; Sano, Kenji*; Saito, Toshiyuki*

Nihon Zairyo Gakkai Dai-44-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.46 - 50, 2010/07

Relaxation process of surface compressive residual stress during tensile or compressive loading on a laser peened aluminum alloy was investigated. The residual stress was measured by X-ray, synchrotron and neutron diffractions and analyzed by a finite element method. The relaxation process clarified in this study was described as follows. When the tensile loading was increased, plastic deformation was occurred at the tensile residual stress region that existed inside of the material to be balanced with the surface compressive residual stress. On the other hand, when the compressive loading was applied, the plastic deformation was started at the maximum compressive residual stress region located just beneath the surface. Because the plastic deformation of the inside of the material induced the redistribution of the residual stress in the sample, the surface compressive residual stress was relaxed prior to the surface yielding.