PSTEP: Project for solar-terrestrial environment prediction

Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.

Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12

https://doi.org/10.1186/s40623-021-01486-1

The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.

Insight into Kondo screening in the intermediate-valence compound SmOsSb uncovered by soft X-ray magnetic circular dichroism

Saito, Yuji; Fujiwara, Hidenori*; Yasui, Akira*; Kadono, Toshiharu*; Sugawara, Hitoshi*; Kikuchi, Daisuke*; Sato, Hideyuki*; Suga, Shigemasa*; Yamasaki, Atsushi*; Sekiyama, Akira*; et al.

Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10

https://doi.org/10.1103/PhysRevB.102.165152

Outline of Japan Atomic Energy Agency's Okuma Analysis and Research Center, 2; Labolatory-1

Sugaya, Yuki; Sakazume, Yoshinori; Akutsu, Hideyuki; Inoue, Toshihiko; Yoshimochi, Hiroshi; Sato, Soichi; Koyama, Tomozo; Nakayama, Shinichi

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 8 Pages, 2017/00

http://hotlab.sckcen.be/proceedings

The Japan Atomic Energy Agency has been developing the research and development facilities, "Okuma Analysis and Research Center", in order to ascertain the properties of radioactive wastes and fuel debris towards the decommissioning of TEPCO's Fukushima Daiichi Nuclear Power Station. This paper outlines the concept of "Laboratory-1" which will analyze low and medium level samples in the Okuma Analysis and Research Center with a focus on the research plan.

A Study on the method of an equivalent continuous body modelling using crack tensor theory in the Mizunami Underground Research Laboratory Project

Sanada, Hiroyuki; Sato, Toshinori; Tanno, Takeo*; Hikima, Ryoichi*; Tada, Hiroyuki*; Kumasaka, Hiroo*; Ishii, Takashi*; Sakurai, Hideyuki*

JAEA-Research 2014-006, 124 Pages, 2014/06

JAEA-Research-2014-006.pdf:11.26MB

Japan Atomic Energy Agency has been implementing the Mizunami Underground Research Laboratory (MIU) Project in order to develop the comprehensive investigation techniques for the geological environment and the engineering techniques to construct a deep underground laboratory in crystalline rock. In the rock mechanical study in the MIU Project, the development of the evaluation method for the excavation damaged zone due to excavation of shafts and research galleries is one of the important issues. In this report, crack tensor was calculated using the tunnel wall mapping and rock mechanical test results in the shaft and research galleries in the MIU. Two dimension excavation analysis was conducted at the Ventilation Shaft and GL -500 m Sub Stage using the calculated crack tensor at GL -500 m. Based on calculated crack tensor at GL 500 m, validation of the crack tensor at GL -500 m estimated during Phase I was verified. Relative error of crack tensor was calculated in order to examine variation of relative error to the scale of observation areas.

Chemical state information of bulk specimens obtained by SEM-based soft-X-ray emission spectrometry

Terauchi, Masami*; Koshiya, Shogo*; Sato, Futami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy and Microanalysis, 20(3), p.692 - 697, 2014/06

https://doi.org/10.1017/S1431927614000439

Electron beam induced soft-X-ray emission spectroscopy (SXES) by using a grating spectrometer has been introduced to a conventional scanning electron microscope (SEM) for characterizing desired specimen areas of bulk materials. The spectrometer was designed as a grazing-incidence flat-field optics by using aberration corrected (varied-line-spacing) gratings and a multi-channel-plate detector combined with a charge-coupled-device camera, which has already applied for a transmission electron microscope. The best resolution was confirmed as 0.13 eV at Mg L-emission (50 eV), which value is comparable to that of recent dedicated electron energy-loss spectroscopy instruments. This SXES-SEM instrument presents density of states of simple metals of bulk Mg and Li. Apparent band structure effects have been observed in Si L-emission of Si-wafer, P L-emission of GaP-wafer, and Al L-emissions of intermetallic compounds of AlCo, AlPd, AlPt, and AlAu.

Construction of a SXES spectrometer for a conventional SEM

Terauchi, Masami*; Koshiya, Shogo*; Sato, Futami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy and Microanalysis, 19(Suppl.2), p.1278 - 1279, 2013/08

https://doi.org/10.1017/S1431927613008386

We have been developed and tested soft-X-ray emission spectroscopy (SXES) instruments by attaching to TEM and EPMA. The spectrometer has an energy range form 50-4000 eV by using four varied-line-spacing (aberration corrected) gratings. This SXES spectrometer inform us energy states of valence electrons (bonding electrons) form an identified specimen area by electron microscopy, which cannot be obtained by EELS and EDS. This provides not only the probing method for the energy states of valence electrons but also a sensitive tool for elemental and chemical identification. The spectrometer has applied also to a SEM (JEOL JSM-6480LV). As SEM can use a larger probe current and excitation volume of specimen than those of TEM, the detection time is about one order shorter than that of TEM. The energy resolution evaluated at AL-Ledge is 0.16 eV. The spectrum of LaB shows apparent intensity corresponds to B-K Fermi edge, showing chemical state of boron.

Magnetic excitation in totally symmetric staggered ordered phase of PrFeP

Iwasa, Kazuaki*; Hao, L.*; Kogi, Masafumi*; Kuwahara, Keitaro*; Mignot, J.-M.*; Sugawara, Hitoshi*; Aoki, Yuji*; Matsuda, Tatsuma; Sato, Hideyuki*

Journal of the Physical Society of Japan, 81(9), p.094711_1 - 094711_9, 2012/09

https://doi.org/10.1143/JPSJ.81.094711

Microscopic study of antiferromagnetic ground state and possible high-field ordered state in CeOsSb using muon spin rotation and relaxation

Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Sato, Kazuhiko*; Aoki, Yuji*; Toda, Shizuka*; Kikuchi, Daisuke*; Sato, Hideyuki*; Baines, C.*

Physical Review B, 82(1), p.014420_1 - 014420_8, 2010/07

https://doi.org/10.1103/PhysRevB.82.014420

An antiferromagnetic (AFM) ground state and a possible high-field ordered state in magnetic fields T of a filled-skutterudite compound CeOsSb were investigated by the muon spin rotation and relaxation method. In a zero applied field, a spontaneous local filed due to the weak AFM ordering was observed below 1.6 K. The magnetic volume fraction gradually increases below 1.6 K with decreasing temperature, suggesting that this phase is sensitive to sample quality. The magnitude of the ordered dipole moment in the AFM state was estimated to be in the range from 0.11 to 0.17 /Ce at 0.1 K. In a field of 2 T applied along the [001] direction, clear anomalies in the muon Knight shift and line width were observed at 1.5 K, consistent with the phase transition scenario into the high-field ordered state suggested from specific heat, resistivity, elastic, and NMR anomalies.

Possible low-energy excitations of multipoles in SmRuP probed by muon spin relaxation

Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Heffner, R. H.; Nishida, Nobuhiko*; Sato, Kazuhiko*; Sugawara, Hitoshi*; Aoki, Yuji*; Kikuchi, Daisuke*; Sato, Hideyuki*

Physica B; Condensed Matter, 404(5-7), p.761 - 764, 2009/04

https://doi.org/10.1016/j.physb.2008.11.179

We report on detailed longitudinal field (LF) SR studies in SmRuP in order to characterize magnetic fluctuations in a magnetically ordered state below K. A magnitude and fluctuation rate of the fluctuating field are derived as functions of temperature from LF dependence of the longitudinal relaxation rate. Possible low-energy excitations of magnetic multipoles are discussed.

Novel features in filled skutterudites containing rare-earth elements with a plural number of 4f-electrons

Sato, Hideyuki*; Aoki, Yuji*; Kikuchi, Daisuke*; Sugawara, Hitoshi*; Higemoto, Wataru; Oishi, Kazuki; Ito, Takashi; Heffner, R. H.; Saha, S. R.*; Koda, Akihiro*; et al.

Physica B; Condensed Matter, 404(5-7), p.749 - 753, 2009/04

https://doi.org/10.1016/j.physb.2008.11.182

Wide varieties of strongly correlated electron phenomena are performed on the stage of a filled skutterudite structure. Especially when one of the players contains a plural number of 4f electrons, the orbital degrees of freedom play a major role as a new type of nonmagnetic and/or weak-magnetic phenomena. Several examples found in Pr- and Sm-based filled skutterudites are introduced in relation to muon spin relaxation experiments.