Impact of the ground-state 4 symmetry for anisotropic hybridization in the heavy-fermion superconductor CeNiGe

Fujiwara, Hidenori*; Nakatani, Yasuhiro*; Aratani, Hidekazu*; Kanai-Nakata, Yuina*; Yamagami, Kohei*; Hamamoto, Satoru*; Kiss, Takayuki*; Yamasaki, Atsushi*; Higashiya, Atsushi*; Imada, Shin*; et al.

Physical Review B, 108(16), p.165121_1 - 165121_10, 2023/10

https://doi.org/10.1103/PhysRevB.108.165121

Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

Result of measurement of the ambient dose equivalent rates by car-borne surveys using KURAMA-II from 2012 until 2019

Ando, Masaki; Saito, Kimiaki

JAEA-Technology 2021-032, 66 Pages, 2022/03

JAEA-Technology-2021-032.pdf:3.84MB

Since the occurrence of the accident at the TEPCO Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency (JAEA) has been conducting a series of car-borne survey over a wide area in the eastern part of Japan using the monitoring system KURAMAII. In this report, outline of the car-borne surveys are summarized and the following characteristics of the temporal changes in each prefecture and region were investigated using the measured data obtained from 2012 to 2019; 1) Average and maximum values for each prefecture for the six years from 2014 to 2019, 2) Average values for each prefecture from 2012 to 2019, 3) Average values for each evacuation order area category, regional category, and northern Soso-area municipality in Fukushima Prefecture from 2012 to 2019, and 4) Average and maximum values for each municipality in each prefecture for four times (at almost two-year intervals) of the measurement results from 2012 to 2018.

Observation of the angular momentum compensation by Barnett effect and NMR

Chudo, Hiroyuki; Imai, Masaki; Matsuo, Mamoru; Maekawa, Sadamichi; Saito, Eiji

Journal of the Physical Society of Japan, 90(8), p.081003_1 - 081003_11, 2021/08

https://doi.org/10.7566/JPSJ.90.081003

Determination of parameters for an equation to obtain natural background radiation using KURAMA-II loaded with C12137-01 type CsI(Tl) detector

Ando, Masaki; Matsuda, Norihiro; Saito, Kimiaki

Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(1), p.34 - 39, 2021/03

https://doi.org/10.3327/taesj.J20.007

We measured count rates and air dose rates at 11 measurement points where the influence of the Fukushima Dai-ichi Nuclear Power Plant accident could be ignored to obtain parameters for a background equation applying to KURAMA-II loaded with the high sensitivity CsI(Tl) detector, C12137-01. It was found that the sensitivity of KURAMA-II (C12137-01) was about 10 times or more for background measurement, compared with KURAMA-II loaded with the standard type CsI(Tl) detector, C12137. A background equation for the energy range of 1400-2000 keV was determined as, y (Sv/h)=0.062 x (cps). We evaluated background air dose rates using KURAMA-II (C12137-01) for 71 municipalities and compared them with the previous study using KURAMA-II (C12137). Evaluated background air dose rates in this study were almost equal to those in the previous study. We confirmed that the background equation evaluated in this study was applicable for the KURAMA-II (C12137-01).

Direct observation of the magnetic ordering process in the ferromagnetic semiconductor GaMnAs via soft X-ray magnetic circular dichroism

Takeda, Yukiharu; Oya, Shinobu*; Pham, N. H.*; Kobayashi, Masaki*; Saito, Yuji; Yamagami, Hiroshi; Tanaka, Masaaki*; Fujimori, Atsushi*

Journal of Applied Physics, 128(21), p.213902_1 - 213902_11, 2020/12

https://doi.org/10.1063/5.0031605

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

Observation of magnon polarization

Nambu, Yusuke*; Barker, J.*; Okino, Yuki*; Kikkawa, Takashi*; Shiomi, Yuki*; Enderle, M.*; Weber, T.*; Winn, B.*; Graves-Brook, M.*; Tranquada, J. M.*; et al.

Physical Review Letters, 125(2), p.027201_1 - 027201_6, 2020/07

https://doi.org/10.1103/PhysRevLett.125.027201

The Deposition densities of radiocesium and the air dose rates in undisturbed fields around the Fukushima Dai-ichi Nuclear Power Plant; Their temporal changes for five years after the accident

Mikami, Satoshi; Tanaka, Hiroyuki*; Matsuda, Hideo*; Sato, Shoji*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Suzuki, Takeo*; Sakamoto, Ryuichi*; Ando, Masaki; Saito, Kimiaki

Journal of Environmental Radioactivity, 210, p.105941_1 - 105941_12, 2019/12

AA2019-0019.pdf:2.65MB

https://doi.org/10.1016/j.jenvrad.2019.03.017

The deposition densities of radiocesium and the air dose rates were repeatedly measured in a large number of undisturbed fields within the 80km zone that surrounds the Fukushima Dai-ichi Nuclear Power Plant site between 2011 and 2016, and features of their temporal changes were clarified. The average air dose rate excluding background radiation in this zone decreased to about 20% of the initial value during the period from June 2011 to August 2016, which was essentially a result of the radioactive decay of Cs with a half-life of 2.06y. The air dose rate reduction was faster than that expected from the decay of radiocesium by a factor of about two, with most of this reduction being attributed to the penetration of radiocesium into the soil. The average deposition densities of Cs and Cs in fields that were not decontaminated were found to have decreased nearly according to their expected radioactive decay, which indicated that the movement of radiocesium in the horizontal direction was relatively small. The effect of decontamination was apparently observed in the measurements of air dose rates and deposition densities. Nominally, the average air dose rates in the measurement locations were reduced by about 20% by decontamination and other human activities, of which accurate quantitative analysis is and continue to be a challenge.