Nonlinear enhancement of coherent magnetization dynamics

Elyasi, M.*; Yamamoto, Kei; Hioki, Tomosato*; Makiuchi, Takahiko*; Shimizu, Hiroki*; Saito, Eiji*; Bauer, G. E. W.*

Physical Review B, 109(18), p.L180402_1 - L180402_7, 2024/05

https://doi.org/10.1103/PhysRevB.109.L180402

Level structures of Ca cast doubt on a doubly magic Ca

Chen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.

Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08

https://doi.org/10.1016/j.physletb.2023.138025

Gamma decays were observed in Ca and Ca following quasi-free one-proton knockout reactions from Sc. For Ca, a ray transition was measured to be 1456(12) keV, while for Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the and orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic Ca and potentially drives the dripline of Ca isotopes to Ca or even beyond.

Superconducting spin reorientation in spin-triplet multiple superconducting phases of UTe

Kinjo, Katsuki*; Fujibayashi, Hiroki*; Matsumura, Hiroki*; Hori, Fumiya*; Kitagawa, Shunsaku*; Ishida, Kenji*; Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Nakamura, Ai*; et al.

Science Advances (Internet), 9(30), p.2736_1 - 2736_6, 2023/07

https://doi.org/10.1126/sciadv.adg2736

Large reduction in the -axis knight shift on UTe with = 2.1 K

Matsumura, Hiroki*; Fujibayashi, Hiroki*; Kinjo, Katsuki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Nakamura, Ai*; Shimizu, Yusei*; et al.

Journal of the Physical Society of Japan, 92(6), p.063701_1 - 063701_5, 2023/05

https://doi.org/10.7566/JPSJ.92.063701

Development of safety design philosophy of HTTR-Heat Application Test Facility

Aoki, Takeshi; Shimizu, Atsushi; Noguchi, Hiroki; Kurahayashi, Kaoru; Yasuda, Takanori; Nomoto, Yasunobu; Iigaki, Kazuhiko; Sato, Hiroyuki; Sakaba, Nariaki

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 9 Pages, 2023/05

The safety design philosophy is developed for the HTTR (High Temperature Engineering Test Reactor) heat application test facility connecting high temperature gas-cooled reactor (HTGR) and the hydrogen production plant. The philosophy was proposed to apply proven conventional chemical plant standards to the hydrogen production facility for ensuring public safety against anticipated disasters caused by high pressure and combustible gases. The present study also proposed the safety design philosophy to meet specific safety requirements identified to the nuclear facilities with coupling to the hydrogen production facility such as measures to ensure a capability of normal operation of the nuclear facility against a fire and/or explosion of leaked combustible material, and fluctuation of amount of heat removal occurred in the hydrogen production plant. The safety design philosophy will be utilized to establish its basic and detailed designs of the HTTR-heat application test facility.

Development plan for coupling technology between high temperature gas-cooled reactor HTTR and Hydrogen Production Facility, 2; Development plan for coupling equipment between HTTR and Hydrogen Production Facility

Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Okita, Shoichiro; Ishii, Katsunori; Kurahayashi, Kaoru; Yasuda, Takanori; Tanaka, Masato; Isaka, Kazuyoshi; Noguchi, Hiroki; et al.

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 6 Pages, 2023/05

Drastic change in magnetic anisotropy of UTe under pressure revealed by Te-NMR

Kinjo, Katsuki*; Fujibayashi, Hiroki*; Nakamine, Genki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Nakamura, Ai*; Shimizu, Yusei*; et al.

Physical Review B, 105(14), p.L140502_1 - L140502_5, 2022/04

https://doi.org/10.1103/PhysRevB.105.L140502

Slow electronic dynamics in the paramagnetic state of UTe

Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Haga, Yoshinori; Tokiwa, Yoshifumi; Opletal, P.; Fujibayashi, Hiroki*; Kinjo, Katsuki*; Kitagawa, Shunsaku*; Ishida, Kenji*; et al.

Journal of the Physical Society of Japan, 91(2), p.023707_1 - 023707_5, 2022/02

https://doi.org/10.7566/JPSJ.91.023707

Te NMR experiments in field () applied along the easy magnetization axis (the -axis) revealed slow electronic dynamics developing in the paramagnetic state of UTe. The observed slow fluctuations are concerned with a successive growth of long-range electronic correlations below 3040 K, where the spin susceptibility along the hard magnetization axis (the -axis) shows a broad maximum. The experiments also imply that tiny amounts of disorder or defects locally disturb the long-range electronic correlations and develop an inhomogeneous electronic state at low temperatures, leading to a low temperature upturn observed in the bulk-susceptibility in . We suggest that UTe would be located on the paramagnetic side near an electronic phase boundary, where either the magnetic or Fermi-surface instability would be the origin of the characteristic fluctuations.

High-spin states in S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.

Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03

https://doi.org/10.1103/PhysRevC.103.034327

= 32 shell closure below calcium; Low-lying structure of Ar

Corts, M. L.*; Rodriguez, W.*; Doornenbal, P.*; Obertelli, A.*; Holt, J. D.*; Menndez, J.*; Ogata, Kazuyuki*; Schwenk, A.*; Shimizu, Noritaka*; Simonis, J.*; et al.

Physical Review C, 102(6), p.064320_1 - 064320_9, 2020/12

AA2020-0748.pdf:0.75MB

https://doi.org/10.1103/PhysRevC.102.064320

Low-lying excited states in the = 32 isotope Ar were investigated by in-beam -ray spectroscopy following proton- and neutron-knockout, multinucleon removal, and proton inelastic scattering at the RIKEN Radioactive Isotope Beam Factory. The energies of the two previously reported transitions have been confirmed, and five additional states are presented for the first time, including a candidate for a 3 state. The level scheme built using coincidences was compared to shell-model calculations in the model space and to predictions based on chiral two- and three-nucleon interactions. Theoretical proton- and neutron-knockout cross sections suggest that two of the new transitions correspond to 2 states, while the previously proposed 4 state could also correspond to a 2 state.