Magnetization switching process by dual spin-orbit torque in interlayer exchange-coupled systems

Masuda, Hiroto*; Yamane, Yuta*; Seki, Takeshi*; Raab, K.*; Dohi, Takaaki*; Modak, R.*; Uchida, Kenichi*; Ieda, Junichi; Klui, M.*; Takanashi, Koki

Applied Physics Letters, 122(16), p.162402_1 - 162402_7, 2023/04

https://doi.org/10.1063/5.0140328

Conversion factors bridging radioactive fission product distributions in the primary containment vessel of Fukushima Daiichi NPP and dose rates measured by the containment atmosphere monitoring system

Uchida, Shunsuke; Pellegrini, M.*; Naito, Masanori*

Nuclear Engineering and Design, 380, p.111303_1 - 111303_11, 2021/08

https://doi.org/10.1016/j.nucengdes.2021.111303

Multi-term FP analysis procedures were developed to determine FP distribution all over F1 not only for analyzing accident propagation but also for planning its decommissioning projects. They should be validated based on the measured FP data. One of the useful tools for their validation was application of the dose rate data monitored by the containment atmosphere monitoring system (CAMS). However, in order to compare the data with different characteristics and dimensional units, e.g., FP distribution (kg, Bq) and dose rate (Sv/h), application of the conversion factors bridging them would be effective and useful. In order to prepare speedy, easy-to-handle and tractable procedures to calculate radiation dose rates at the CAMS detector locations, dose rate conversion factors were determined for major source locations and major radionuclides. The dose rates could be easily calculated by multiplying FP amounts obtained with the multiterm FP analysis procedures by the conversion factors.

A New approach for measuring the muon anomalous magnetic moment and electric dipole moment

Abe, Mitsushi*; Bae, S.*; Beer, G.*; Bunce, G.*; Choi, H.*; Choi, S.*; Chung, M.*; da Silva, W.*; Eidelman, S.*; Finger, M.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(5), p.053C02_1 - 053C02_22, 2019/05

https://doi.org/10.1093/ptep/ptz030

This paper introduces a new approach to measure the muon magnetic moment anomaly and the muon electric dipole moment (EDM) at the J-PARC muon facility. The goal of our experiment is to measure and using an independent method with a factor of 10 lower muon momentum, and a factor of 20 smaller diameter storage-ring solenoid compared with previous and ongoing muon g-2 experiments with unprecedented quality of the storage magnetic field. Additional significant differences from the present experimental method include a factor of 1000 smaller transverse emittance of the muon beam (reaccelerated thermal muon beam), its efficient vertical injection into the solenoid, and tracking each decay positron from muon decay to obtain its momentum vector. The precision goal for is a statistical uncertainty of 450 parts per billion (ppb), similar to the present experimental uncertainty, and a systematic uncertainty less than 70 ppb. The goal for EDM is a sensitivity of ecm.

Temperature dependence of the spin Seebeck effect in [FeO/Pt]n multilayers

Ramos, R.*; Kikkawa, Takashi*; Anadn, A.*; Lucas, I.*; Uchida, Kenichi*; Algarabel, P. A.*; Morelln, L.*; Aguirre, M. H.*; Saito, Eiji; Ibarra, M. R.*

AIP Advances (Internet), 7(5), p.055915_1 - 055915_7, 2017/05

https://doi.org/10.1063/1.4974060

Unconventional scaling and significant enhancement of the spin Seebeck effect in multilayers

Ramos, R.*; Kikkawa, Takashi*; Aguirre, M.*; Lucas, I.*; Anadn, A.*; Oyake, Takafumi*; Uchida, Kenichi*; Adachi, Hiroto; Shiomi, Junichiro*; Algarabel, P. A.*; et al.

Physical Review B, 92(22), p.220407_1 - 220407_5, 2015/12

https://doi.org/10.1103/PhysRevB.92.220407

Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet platinum bilayers

Schreier, M.*; Bauer, G. E. W.*; Vasyuchka, V.*; Flipse, J.*; Uchida, Kenichi*; Lotze, J.*; Lauer, V.*; Chumak, A.*; Serga, A.*; Daimon, Shunsuke*; et al.

Journal of Physics D; Applied Physics, 48(2), p.025001_1 - 025001_5, 2015/01

https://doi.org/10.1088/0022-3727/48/2/025001

Progress of the ITER NBI acceleration grid power supply reference design

Toigo, V.*; Zanotto, L.*; Bigi, M.*; Decamps, H.*; Ferro, A.*; Gaio, E.*; Gutirrez, D.*; Tsuchida, Kazuki; Watanabe, Kazuhiro

Fusion Engineering and Design, 88(6-8), p.956 - 959, 2013/10

https://doi.org/10.1016/j.fusengdes.2013.01.013

This paper reports the progress in the reference design of the Acceleration Grid Power Supply (AGPS) of the ITER Neutral Beam Injector (NBI). The design of the AGPS is very challenging, as it shall be rated to provide about 55 MW at 1 MV dc in quasi steady-state conditions; moreover, the procurement of the system is shared between the European Domestic Agency (F4E) and the Japanese Domestic Agency (JADA), resulting in additional design complication due to the need of a common definition of the interface parameters. A critical revision of the main design choices is presented also in light of the definition of some key interface parameters between the two AGPS subsystems. Moreover, the verification of the fulfillment of the requirements in any operational conditions taking into account the tolerance of the different parameters is also reported and discussed.

Observation of the spin Seebeck effect in epitaxial FeO thin films

Ramos, R.*; Kikkawa, Takashi*; Uchida, Kenichi*; Adachi, Hiroto; Lucas, I.*; Aguirre, M.*; Algarabel, P.*; Morelln, L.*; Maekawa, Sadamichi; Saito, Eiji; et al.

Applied Physics Letters, 102(7), p.072413_1 - 072413_5, 2013/02

https://doi.org/10.1063/1.4793486

Thermally driven spin and charge currents in thin NiFeO/Pt films

Meier, D.*; Kuschel, T.*; Shen, L.*; Gupta, A.*; Kikkawa, Takashi*; Uchida, Kenichi*; Saito, Eiji; Schmalhorst, J.-M.*; Reiss, G.*

Physical Review B, 87(5), p.054421_1 - 054421_5, 2013/02

https://doi.org/10.1103/PhysRevB.87.054421

Li(Zn,Mn)As as a new generation ferromagnet based on a I-II-V semiconductor

Deng, Z.*; Jin, C. Q.*; Liu, Q. Q.*; Wang, X. C.*; Zhu, J. L.*; Feng, S. M.*; Chen, L. C.*; Yu, R. C.*; Arguello, C.*; Goko, Tatsuo*; et al.

Nature Communications (Internet), 2, p.1425_1 - 1425_5, 2011/08

https://doi.org/10.1038/ncomms1425

In a prototypical ferromagnet (Ga,Mn)As based on a III-V semiconductor, substitution of divalent Mn atoms into trivalent Ga sites leads to severely limited chemical solubility and metastable specimens available only as thin films. The doping of hole carriers via (Ga,Mn) substitution also prohibits electron doping. To overcome these difficulties, Masek et al. theoretically proposed systems based on a I-II-V semiconductor LiZnAs, where isovalent (Zn,Mn) substitution is decoupled from carrier doping with excess/deficient Li concentrations. Here we show successful synthesis of Li(ZnMn)As in bulk materials. We reported that ferromagnetism with a critical temperature of up to 50 K is observed in nominally Li-excess compounds, which have p-type carriers.