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.

Tuning of ultra-slow muon transport system

Adachi, Taihei*; Ikedo, Yutaka*; Nishiyama, Kusuo*; Yabuuchi, Atsushi*; Nagatomo, Takashi*; Strasser, P.*; Ito, Takashi; Higemoto, Wataru; Kojima, Kenji*; Makimura, Shunsuke*; et al.

JPS Conference Proceedings (Internet), 8, p.036017_1 - 036017_4, 2015/09

https://doi.org/10.7566/JPSCP.8.036017

Temporal and spatial responses of temperature, density and rotation to electron cyclotron heating in JT-60U

Yoshida, Maiko; Ide, Shunsuke; Takenaga, Hidenobu; Honda, Mitsuru; Urano, Hajime; Kobayashi, Takayuki; Nakata, Motoki; Miyato, Naoaki; Kamada, Yutaka

Nuclear Fusion, 53(8), p.083022_1 - 083022_10, 2013/07

https://doi.org/10.1088/0029-5515/53/8/083022

Time and special responses of electron channels and ion channels with central electron cyclotron heating (ECH) have been investigated in JT-60U positive shear H-mode and internal transport barrier (ITB) plasmas. The ion temperature reduces with ECH after the increase in the electron temperature where an increase in the ion heat transport with ECH accompanies an increase in the electron thermal transport. The core electron density decreases with ECH when the density profile is peaked before ECH injection. The counter intrinsic rotation with ECH is identified using H-mode plasmas with small torque input (BAL-NBI). The counter intrinsic rotation is generated after the increase in the electron temperature and correlates with the change in the electron temperature with ECH around the EC deposition. Time scale of the change in the toroidal rotation velocity is about 90-200 ms around the ECH deposition and the time scale is longer compared to those in and .

J-PARC decay muon channel construction status

Strasser, P.*; Shimomura, Koichiro*; Koda, Akihiro*; Kawamura, Naritoshi*; Fujimori, Hiroshi*; Makimura, Shunsuke*; Kobayashi, Yasuo*; Nakahara, Kazutaka*; Kato, Mineo*; Takeshita, Soshi*; et al.

Journal of Physics; Conference Series, 225, p.012050_1 - 012050_8, 2010/06

https://doi.org/10.1088/1742-6596/225/1/012050

Rotation drive and momentum transport with electron cyclotron heating in tokamak plasmas

Yoshida, Maiko; Sakamoto, Yoshiteru; Takenaga, Hidenobu; Ide, Shunsuke; Oyama, Naoyuki; Kobayashi, Takayuki; Kamada, Yutaka; JT-60 Team

Physical Review Letters, 103(6), p.065003_1 - 065003_4, 2009/08

https://doi.org/10.1103/PhysRevLett.103.065003

The role of electron cyclotron range of frequency (ECRF) wave on the toroidal rotation velocity profile has been investigated in JT-60U plasmas by separating the effects of the momentum transport, the intrinsic rotation by pressure gradient and the intrinsic rotation by ECRF. It is found that ECRF increases the toroidal momentum diffusivity and the convection velocity. ECRF drives the CO-intrinsic rotation inside the EC deposition and drives the CTR-intrinsic rotation outside the EC deposition. This CTR-rotation starts from the EC deposition radius and propagates to the edge region.

Development and demonstration of remote experiment system with high security in JT-60U

Ozeki, Takahisa; Suzuki, Yoshio; Totsuka, Toshiyuki; Iba, Katsuyuki*; Sakata, Shinya; Miyato, Naoaki; Isayama, Akihiko; Ide, Shunsuke; Urso, L.*; Behler, K.*; et al.

no journal, , 

Responses of ion and electron channels to electron cyclotron heating in JT-60U

Yoshida, Maiko; Ide, Shunsuke; Takenaga, Hidenobu; Honda, Mitsuru; Urano, Hajime; Kobayashi, Takayuki; Nakata, Motoki; Miyato, Naoaki; Kamada, Yutaka

no journal, , 

In this study, the temporal and spatial responses of electron channels and ion channels to central electron cyclotron heating (ECH) have been investigated in positive shear H-mode plasmas and weak shear plasmas with internal transport barriers (ITBs) on JT-60U. The flattening of ne profile is observed after the increase in Te in the core region. Linear gyrokinetic stability analyses predict that the growth rate of the trapped electron modes, which increase outward particle flux, becomes more pronounced during ECH. Ion temperature around the ITB foot rapidly reduces and the increase in Te precedes the reduction in Ti. From the observations and theoretical analyses, the reduced Ti can be interpreted as the decrease in the critical temperature gradient for the ion temperature gradient mode with ECH. The counter intrinsic rotation with ECH is identified on H-mode plasmas with small torque input where co-current NBs and counter-current NBs are simultaneously injected with the same power.

A Measurement of the final-state dependence of the parity violation in a compound nucleus with La

Goto, Yu*; Ito, Yuki*; Ide, Ikuo*; Ino, Takashi*; Endo, Shunsuke; Oku, Takayuki; Okudaira, Takuya*; Okuizumi, Mao*; Kameda, Kento*; Kawamura, Shiori*; et al.

no journal, , 

no abstracts in English

Characterization of Fe-, Ti-, and W-based high-entropy alloys that mainly have bcc crystal structure (including irradiation effects)

Wakai, Eiichi; Noto, Hiroyuki*; Shibayama, Tamaki*; Iwamoto, Yosuke; Ishida, Taku*; Sato, Koichi*; Yabuuchi, Atsushi*; Yoshiie, Toshimasa*; Takahashi, Toshiharu*; Kobayashi, Yasuhiro*; et al.

no journal, , 

In recent years, it has been reported that high-entropy alloys (HEA) have high strength but good ductility, and they are being researched and developed by cutting-edge research institutions around the world with the aim of finding various applications in progress. In this study, we considered several Fe-based, W-based, and Ti-based HEAs, excluding Co and Ni elements, in order to aim for use in high radiation fields and considering low-activation properties. These materials mainly have a bcc crystal structure and were fabricated using a melting method and their material properties were evaluated. As a result, it was found that Fe-based HEA has properties that exceed the hardness of pure W and has excellent irradiation resistance. In addition, a Ti-based HEA that can be subjected to high-temperature forging and high-temperature rolling has been found, and evaluation of the optimal heat treatment temperature is progressing. The hardness of W-based HEA increased through Hot Isostatic Pressing (HIP) treatment, and it was found to have the world's highest hardness among HEA materials.