Newly found fault outcrops of the Tsuruga fault in the Mihama Town, Fukui Prefecture, Japan

Tateishi, Ryo*; Shimada, Koji; Iwamori, Akiyuki*; Wada, Shinya*; Seno, Shotaro*; Nagata, Ken*

Chishitsugaku Zasshi (Internet), 128(1), p.63 - 64, 2022/04

https://doi.org/10.5575/geosoc.2022.0007

The Tsuruga Fault is an active right-lateral strike-slip fault that is about 20 km in length and distributed in the northeast-southwest direction from the eastern part of Tsuruga City to the southern part of Mihama Town, Fukui Prefecture. The Tsuruga fault borders the Jurassic accretionary complex (mixed rock) and the late Cretaceous granite around the Oritodani area in the Shinjo district of Mihama-cho. Lateral bendings of valleys along the fault in this area are clear geomorphological signatures of fault activity. We briefly report newly found multiple fault outcrops at these bending points with photos of them. This research is the result of joint research by Kansai Electric Power Company, University of Toyama, and JAEA.

Deposition and dispersion of radio-cesium released due to the Fukushima Nuclear accident, 2; Sensitivity to aerosol microphysical properties of Cs-bearing microparticles (CsMPs)

Kajino, Mizuo*; Adachi, Koji*; Igarashi, Yasuhito*; Satou, Yukihiko; Sawada, Morihiro*; Sekiyama, Tsuyoshi*; Zaizen, Yuji*; Saya, Akane*; Tsuruta, Haruo*; Moriguchi, Yuichi*

Journal of Geophysical Research; Atmospheres, 126(1), p.e2020JD033460_1 - e2020JD033460_23, 2021/01

https://doi.org/10.1029/2020JD033460

Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

Sonoda, Tetsu*; Katayama, Ichiro*; Wada, Michiharu*; Iimura, Hideki; Sonnenschein, V.*; Iimura, Shun*; Takamine, Aiko*; Rosenbusch, M.*; Kojima, Takao*; Ahn, D. S.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11

AA2019-0315.pdf:1.37MB

https://doi.org/10.1093/ptep/ptz120

An in-flight separator, BigRIPS, at RIBF in RIKEN provides each experiment with specific nuclides separated from many nuclides produced by projectile fragmentation or in-flight fission. In this process, nuclides other than separated ones are discarded on the slits in BigRIPS, although they include many nuclides interested from the view point of nuclear structure. In order to extract these nuclides for parasitic experiments, we are developing a method using laser ion-source (PALIS). A test experiment with Se beam from RIBF has been performed by using a gas cell set in BigRIPS. Unstable nuclides around Se were stopped in the gas cell in accordance with a calculation using LISE code. The stopping efficiency has been estimated to be about 30%. As a next step, we will establish the technique for extracting reaction products from the gas cell.

First direct mass measurements of nuclides around = 100 with a multireflection time-of-flight mass spectrograph

Ito, Yuta*; Schury, P.*; Wada, Michiharu*; Arai, Fumiya*; Haba, Hiromitsu*; Hirayama, Yoshikazu*; Ishizawa, Satoshi*; Kaji, Daiya*; Kimura, Sota*; Koura, Hiroyuki; et al.

Physical Review Letters, 120(15), p.152501_1 - 152501_6, 2018/04

https://doi.org/10.1103/PhysRevLett.120.152501

Masses of Es, Fm and the transfermium nuclei Md, and No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed neutron shell closure, have been directly measured using a multi-reflection time-of-flight mass spectrograph. The masses of Es and Md were measured for the first time. Using the masses of Md as anchor points for decay chains, the masses of heavier nuclei, up to Bh and Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter derived from three isotopic masses was updated with the new masses and corroborate the existence of the deformed neutron shell closure for Md and Lr.

The Laser and optical system for the RIBF-PALIS experiment

Sonoda, Tetsu*; Iimura, Hideki; Reponen, M.*; Wada, Michiharu*; Katayama, Ichiro*; Sonnenschein, V.*; Takamatsu, Takahide*; Tomita, Hideki*; Kojima, Takao*

Nuclear Instruments and Methods in Physics Research A, 877, p.118 - 123, 2018/01

https://doi.org/10.1016/j.nima.2017.09.055

In order to produce low-energy RI beams at RIKEN RIBF, a laser ion source, PALIS, is under construction. This ion source is based on resonance ionization of RI atoms captured in Ar gas. Because the ion source is located 70m away from lasers, we have developed an optical system for laser beam transport. This system can be controlled remotely when the ion source is not accessible because of high radiation level. The position of laser beam after transport is reasonably stable, and the transport efficiency is about 50%.

Research progress at the Slow Positron Facility in the Institute of Materials Structure Science, KEK

Hyodo, Toshio*; Wada, Ken*; Mochizuki, Izumi*; Kimura, Masao*; Toge, Nobukazu*; Shidara, Tetsuo*; Fukaya, Yuki; Maekawa, Masaki*; Kawasuso, Atsuo*; Iida, Shimpei*; et al.

Journal of Physics; Conference Series, 791(1), p.012003_1 - 012003_8, 2017/02

https://doi.org/10.1088/1742-6596/791/1/012003

no abstracts in English

Negative correlation between electrical response and domain size in a Ti-composition-gradient Pb[(MgNb)Ti]O crystal near the morphotropic phase boundary

Shimizu, Daisuke*; Tsukada, Shinya*; Matsuura, Masato*; Sakamoto, Junya*; Kojima, Seiji*; Namikawa, Kazumichi*; Mizuki, Junichiro; Owada, Kenji

Physical Review B, 92(17), p.174121_1 - 174121_5, 2015/11

https://doi.org/10.1103/PhysRevB.92.174121

The phase diagram and the relationship between the crystal coherence length and electrical response of Pb[(MgNb)Ti]O (PMN-xPT) near the morphotropic phase boundary (MPB) have been precisely investigated using a single crystal with a Ti composition gradient by synchrotron X-ray diffraction and inelastic light scattering at room temperature. The crystal has two boundaries at Ti compositions of 29.0 mol% and 34.7 mol% which correspond to the phase boundaries between the monoclinic B (MB) and C (MC) phases and between the MC and tetragonal (T) phases, respectively. It is shown that there is a strong negative correlation between the electrical response and the crystal coherence length at the sub-m scale. The results are explained by the size effects of domains near the MPB.

Gyrotron development for high-power, long-pulse electron cyclotron heating and current drive at two frequencies in JT-60SA and its extension toward operation at three frequencies

Kobayashi, Takayuki; Moriyama, Shinichi; Yokokura, Kenji; Sawahata, Masayuki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Hoshino, Katsumichi; et al.

Nuclear Fusion, 55(6), p.063008_1 - 063008_8, 2015/06

https://doi.org/10.1088/0029-5515/55/6/063008

A gyrotron enabling high-power, long-pulse oscillations at both 110 GHz and 138 GHz has been developed for electron cyclotron heating (ECH) and current drive (CD) in JT-60SA. Oscillations of 1 MW for 100 s have been demonstrated at both frequencies, for the first time as a gyrotron operating at two frequencies. The optimization of the anode voltage, or the electron pitch factor, using a triode gun was a key to obtain high power and high efficiency at two frequencies. It was also confirmed that the internal losses in the gyrotron were sufficiently low for expected long pulse operation at the higher power level of 1.5 MW. Another important result is that an oscillation at 82 GHz, which enables to use fundamental harmonic waves in JT-60SA while the other two frequencies are used as second harmonics waves, was demonstrated up to 0.4 MW for 2 s. These results of the gyrotron development significantly contribute to enhancing operation regime of the ECH/CD system in JT-60SA.

Method development and reactor physics data evaluation for improving prediction accuracy of fast reactors' minor actinides transmutation performance

Takeda, Toshikazu*; Hazama, Taira; Fujimura, Koji*; Sawada, Shusaku*

Proceedings of International Conference on the Physics of Reactors; The Role of Reactor Physics toward a Sustainable Future (PHYSOR 2014) (CD-ROM), 15 Pages, 2014/09

A national project started in 2013 in Japan entitled "technology development for the environmental burden reduction". The present study is one of the studies adopted as the national project. We are aiming to develop MA transmutation core concepts harmonizing MA transmutation performance with core safety and to improve design accuracy related to MA transmutation performance. To validate and improve design accuracy of the high safety and high MA transmutation performance of SFR cores, we develop methods for calculating the transmutation rate of individual MA nuclides and estimating uncertainty of MA transmutation by using burnup sensitivity. Also we develop reliable reactor physics database to reduce the uncertainty of MA transmutation calculations. The overall consistency of the measured data is investigated by evaluating the usefulness of conventional static data as well as those related to MA transmutation obtained from various facilities like Monju, Joyo, FCA, BFS and PFR.

Intranuclear cascade with emission of light fragment code implemented in the transport code system PHITS

Sawada, Yusuke*; Uozumi, Yusuke*; Nogamine, Sho*; Yamada, Takehiro*; Iwamoto, Yosuke; Sato, Tatsuhiko; Niita, Koji*

Nuclear Instruments and Methods in Physics Research B, 291, p.38 - 44, 2012/11

https://doi.org/10.1016/j.nimb.2012.08.025

The Intranuclear cascade with emission of light fragment (INC-ELF) code has been developed and implemented in the particle and heavy ion transport code system (PHITS). The INC-ELF code explicitly includes nucleon correlations within the framework of the INC model to describe light fragment emissions from nuclear spallation reactions. In addition to the degrees of freedom of nucleons, the developed code also accounts for pions, and , and it can cover the energy range up to 3 GeV. The predictive capabilities of the ELF/PHITS system have been verified through comparison with a diverse set of experimental observations. As a result, our ELF/PHITS code has demonstrated strong predictive capability for all of these data, although areas requiring future study remain due to the lack of experimental data on high-energy cluster production.