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.

Introduction to radiation physics; Third revised edition

Tada, Junichiro*; Nakashima, Hiroshi; Hayano, Ryugo*; Kobayashi, Hitoshi*; Asano, Yoshihiro*

Wakariyasui Hoshasen Butsurigaku; Kaitei 3-Han, 305 Pages, 2018/03

This book is an introduction to radiation physics. Under the concept of "linking physics of high school and radiation physics" for readers with high school graduation degree, we are doing simple commentary on the basis of qualitative explanation as much as possible. This book begins with "What is Radiation Physics", and consists of 12 chapters, including introductory special relativity, introductory quantum theory, structures of atoms and nuclei, radiations, radioactivity, interactions between radiation and matter, accelerators, radiation dose and so on.

Experimental studies of passive neutron measurement for fuel debris at Fukushima Daiichi Nuclear Power Plants

Nagatani, Taketeru; Shirato, Atsuhiko*; Kosuge, Yoshihiro*; Sato, Takashi*; Kawakubo, Yoko; Shiromo, Hideo; Asano, Takashi

Proceedings of INMM 56th Annual Meeting (Internet), 10 Pages, 2015/07

As one of the candidate material accountancy technologies for the fuel debris at Fukushima Daiichi Nuclear Power Plants (1F), we propose the application of a passive neutron technique. The applicability of the new concept to the fuel debris at 1F was evaluated by simulation and the results were presented at the last INMM annual meeting. As the next phase, we conducted experimental tests to confirm the validity of the simulation results. Because actual fuel debris or irradiated fuel cannot be handled at our facility due to a licensing limitation, un-irradiated MOX samples, neutron absorbers and Cf-252 sources were utilized as the best available material to imitate the property of the fuel debris and various configurations were measured using an Epithermal Neutron Multiplicity Counter. The fissile mass in the samples, neutron absorber mass surrounding the samples and intensity of Cf-252 source were varied to confirm the correlation between DDSI response and the leakage multiplication. Test results agreed well with the trend of the simulation results. This indicates that DDSI has sufficient capability to evaluate the leakage multiplication of a sample which includes an unknown amount of fissile material and neutron absorber such as the fuel debris at 1F. This paper provides experimental studies of passive neutron measurement based on the combination of DDSI technique and coincidence counting for fuel debris at 1F.

Performance upgrade in the JAEA actinide science beamline BL23SU at SPring-8 with a new twin-helical undulator

Saito, Yuji; Fukuda, Yoshihiro; Takeda, Yukiharu; Yamagami, Hiroshi; Takahashi, Sunao*; Asano, Yoshihiro*; Hara, Toru*; Shirasawa, Katsutoshi*; Takeuchi, Masao*; Tanaka, Takashi*; et al.

Journal of Synchrotron Radiation, 19(3), p.388 - 393, 2012/05

https://doi.org/10.1107/S0909049512006772

The soft X-ray beamline BL23SU at SPring-8 has undergone an upgrade with a twin-helical undulator of in-vacuum type to enhance the experimental capabilities of the end stations. The new light source with a fast helicity-switching operation allows not only the data throughput but also the sensitivity in X-ray magnetic circular dichroism (XMCD) to be improved. The operational performance and potential are described by presenting XMCD results of paramagnetic -US measured with a 10 T superconducting magnet.

Calculations for the availability of photoneutron using synchrotron radiation

Asano, Yoshihiro; Kawashima, Yoshitaka*

Radiation Protection Dosimetry, 115(1-4), p.176 - 180, 2005/12

https://doi.org/10.1093/rpd/nci175

no abstracts in English

Comparison of synchrotron radiation calculations between analytical codes(STAC8,PHOTON) and Monte Carlo codes (FLUKA,EGS4)

Liu, J. C.*; Fasso, A.*; Prinz, A.*; Rokni, S.*; Asano, Yoshihiro

Radiation Protection Dosimetry, 116(1-4), p.658 - 661, 2005/12

https://doi.org/10.1093/rpd/nci207

no abstracts in English

3rd International Workshop on Radiation Safety of Synchrotron Radiation Sources (Radsynch '04)

Asano, Yoshihiro

SPring-8 Information, 10(1), p.35 - 38, 2005/01

no abstracts in English

Measurement of absolute intensity for high energy SR photons using calorimeter

Asano, Yoshihiro; Kishi, Noriyuki*; Moriya, Takahiro*

AIP Conference Proceedings 705, p.564 - 567, 2004/00

https://doi.org/10.1063/1.1757859

no abstracts in English

Evidence for a narrow = +1 Baryon resonance in photoproduction from the neutron

Nakano, Takashi*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Date, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujiwara, Mamoru; et al.

Physical Review Letters, 91(1), p.012002_1 - 012002_4, 2003/07

https://doi.org/10.1103/PhysRevLett.91.012002

no abstracts in English

Comparison of synchrotron radiation calculation between EGS4, FLUKA, PHOTON and STAC8

Asano, Yoshihiro; Liu, J. C.*

KEK Proceedings 2002-18, p.48 - 54, 2003/01

The light energy was not higher than soft X-rays so that the radiation safety for synchrotron radiation passed for unworthy issues of attention. With constructing and operating the third generation facilities such as SPring-8, however, high energy synchrotron radiation of extremely high intense is available, and high accuracy should be required in the shielding and safety design for the beam of synchrotron radiation. Furthermore, the middle size facilities such as CLS (Canadian Light Source) are now under construction and the optimum design of shielding is desired to construct the beamline with safety and compact. It is necessary for the purpose to verify the detailed evaluation technique. Therefore, taking the SPEAR3 bending magnet and BL11-3 wiggler beamlines in the examples, the characteristics of the codes were investigated in comparison with synchrotron radiation shielding design code PHOTON, STAC8 and Monte Carlo simulation code EGS4, FLUKA