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Lyons, T. P.*; Puebla, J.*; Yamamoto, Kei; Deacon, R. S.*; Hwang, Y.*; Ishibashi, Koji*; Maekawa, Sadamichi*; Otani, Yoshichika*
Physical Review Letters, 131(19), p.196701_1 - 196701_6, 2023/11
Times Cited Count:8 Percentile:87.40(Physics, Multidisciplinary)Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count:18 Percentile:95.53(Multidisciplinary Sciences)no abstracts in English
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
Times Cited Count:3 Percentile:75.57(Astronomy & Astrophysics)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.
Takahara, Shogo; Charnock, T. W.*; Silva, K.*; Hwang, W. T.*; Lee, J.*; Yu, C.*; Kamboj, S.*; Yankovich, T.*; Thiessen, K. M.*
Journal of Radiological Protection, 42(2), p.020517_1 - 020517_13, 2022/06
Times Cited Count:0 Percentile:0.00(Environmental Sciences)State-of-the-art dose assessment models were applied to estimate doses to the population in urban areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Assessment results were compared among five models, and comparisons of model predictions with actual measurements were also made. Assessments were performed using both probabilistic and deterministic approaches. Predicted dose distributions in indoor and outdoor workers from a probabilistic approach were in good agreement with the actual measurements. In addition, when the models were applied to assess the doses to a representative person, based on a concept suggested by the International Commission on Radiological Protection (ICRP), it was evident that doses to the representative person obtained with a deterministic approach were always higher than those obtained with a probabilistic approach.
Thiessen, K. M.*; Boznar, M. Z.*; Charnock, T. W.*; Chouhan, S. L.*; Federspiel, L.; Grai, B.*; Grsic, Z.*; Helebrant, J.*; Hettrich, S.*; Hulka, J.*; et al.
Journal of Radiological Protection, 42(2), p.020502_1 - 020502_8, 2022/06
Times Cited Count:5 Percentile:72.25(Environmental Sciences)Kumagai, Tomohisa*; Miura, Yasufumi*; Miura, Naoki*; Marie, S.*; Almahdi, R.*; Mano, Akihiro; Li, Y.; Katsuyama, Jinya; Wada, Yoshitaka*; Hwang, J.-H.*; et al.
Journal of Pressure Vessel Technology, 144(1), p.011509_1 - 011509_18, 2022/02
Times Cited Count:1 Percentile:12.41(Engineering, Mechanical)To predict fracture behavior for ductile materials, some ductile fracture simulation methods different from classical approaches have been investigated based on appropriate models of ductile fracture. For the future use of the methods to overcome restrictions of classical approaches, the applicability to the actual components is of concern. In this study, two benchmark problems on the fracture tests supposing actual components were provided to investigate prediction ability of simulation methods containing parameter decisions. One was the circumferentially through-wall and surface cracked pipes subjected to monotonic bending, and the other was the circumferentially through-wall cracked pipes subjected to cyclic bending. Participants predicted the ductile crack propagation behavior by their own approaches, including FEM employed GTN yielding function with void ratio criterion, are FEM employed GTN yielding function, FEM with fracture strain or energy criterion modified by stress triaxiality, XFEM with J or delta J criterion, FEM with stress triaxiality and plastic strain based ductile crack propagation using FEM, and elastic-plastic peridynamics. Both the deformation and the crack propagation behaviors for monotonic bending were well reproduced, while few participants reproduced those for cyclic bending. To reproduce pipe deformation and fracture behaviors, most of groups needed parameters which were determined toreproduce pipe deformation and fracture behaviors in benchmark problems themselves and it is still difficult to reproduce them by using parameters only from basic materials tests.
Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count:18 Percentile:73.44(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree () knockout reaction. The sum of spectroscopic factors of orbital is found to be 1.0 0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 35% O, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Jung, W.*; Ahn, J. K.*; Hasegawa, Shoichi; Hicks, K.*; Hwang, S.*; Ichikawa, Yudai; Kim, S.*; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi
JPS Conference Proceedings (Internet), 27, p.011007_1 - 011007_6, 2019/11
Nakagawa, Manami*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; et al.
JPS Conference Proceedings (Internet), 17, p.012009_1 - 012009_4, 2017/07
Tamura, Hirokazu*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; et al.
JPS Conference Proceedings (Internet), 17, p.011004_1 - 011004_11, 2017/07
Yang, S. B.*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; et al.
JPS Conference Proceedings (Internet), 17, p.012004_1 - 012004_4, 2017/07
Hwang, S.; Imai, Kenichi
JPS Conference Proceedings (Internet), 17, p.033010_1 - 033010_2, 2017/07
Sako, Hiroyuki; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Hicks, K.*; Ahn, J. K.*; Kim, S. H.*; Lee, J. W.*; Hwang, S. H.*
Proceedings of Science (Internet), 281, p.266_1 - 266_5, 2017/05
Although baryon resonances have been studied for a long time, our knowledge on their properties are still limited. Recently a Dynamical-Couple Channel (DCC) model shows there are significant contributions of reactions to these baryon resonances. However, there are only 240 thousand events of reaction data measured in 1970's. Thus, we proposed an experiment E45 to study baryon resonances in reaction utilizing Hz beams at J-PARC. We aim at clarifying most of baryon mass levels. We measure these reactions in a large acceptance Time Projection Chamber inside a Helmholtz dipole magnet. We will measure these reactions in small momentum steps over a large beam momentum range and perform partial wave analysis to extract properties of each resonance. In this presentation, we will show the experimental design, expected results in simulations, and the status of the detectors.
Sako, Hiroyuki; Harada, Hiroyuki; Sakaguchi, Takao*; Chujo, Tatsuya*; Esumi, Shinichi*; Gunji, Taku*; Hasegawa, Shoichi; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; et al.
Nuclear Physics A, 956, p.850 - 853, 2016/12
Times Cited Count:13 Percentile:66.42(Physics, Nuclear)Farinella, D. M.*; Lau, C. K.*; Zhang, X. M.*; Koga, J. K.; Taimourzadeh, S.*; Hwang, Y.*; Abazajian, K.*; Canac, N.*; Ebisuzaki, Toshikazu*; Taborek, P.*; et al.
Physics of Plasmas, 23(7), p.073107_1 - 073107_10, 2016/07
Times Cited Count:4 Percentile:20.42(Physics, Fluids & Plasmas)Yamamoto, T. O.*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji; Nakada, Yoshiyuki; Sako, Hiroyuki; et al.
Physical Review Letters, 115(22), p.222501_1 - 222501_5, 2015/11
Times Cited Count:72 Percentile:92.59(Physics, Multidisciplinary)Kim, S. H.*; Hwang, S.; Ahn, J. K.*; Ekawa, Hiroyuki; Hayakawa, Shuhei; Hong, B.*; Hosomi, Kenji; Imai, Kenichi; Kim, M. H.*; Lee, J. Y.*; et al.
Nuclear Instruments and Methods in Physics Research A, 795, p.39 - 44, 2015/09
Times Cited Count:4 Percentile:31.62(Instruments & Instrumentation)Sako, Hiroyuki; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sato, Susumu; Sugimura, Hitoshi
Proceedings of Science (Internet), 213, p.300_1 - 300_4, 2015/07
We develop a TPC (Time Projection Chamber) using GEM (Gas Electron Multiplier) to search for H-dibaryon at J-PARC E42 experiment. We evaluated performance of a small prototype TPC. We performed a long term operation test for one month which is similar term as E42. We suppressed hit position distortion with 0.2 mm due to ion backflow.
Morino, Yuhei*; Hwang, S.; Imai, Kenichi; Tanida, Kiyoshi; LEPS Collaboration*; 46 of others*
Progress of Theoretical and Experimental Physics (Internet), 2015(1), p.013D01_1 - 013D01_11, 2015/01
Times Cited Count:9 Percentile:54.82(Physics, Multidisciplinary)Sako, Hiroyuki; Sugimura, Hitoshi; Ahn, J. K.*; Han, Y.*; Hasegawa, Shoichi; Hwang, S. H.*; Ichikawa, Yudai; Imai, Kenichi; Kiuchi, Ryuta*; Ozawa, Kyoichiro; et al.
Nuclear Instruments and Methods in Physics Research A, 763, p.65 - 81, 2014/11
Times Cited Count:5 Percentile:37.18(Instruments & Instrumentation)We developed a prototype TPC for an H-dibaryon search experiment at J-PARC. To investigate its performance, we conducted tests with Ar-CH (90:10) and Ar-CF (95:5), where the former is mainly used. The detection efficiency was measured to be 98% at the beam rate up to cps/cm, and 90% at the rate of cps/cm. Based on the measured horizontal resolution of 0.19-0.46 mm at the drift length of 5-20 cm, the position resolution of better than 0.3 mm is estimated in 1 T magnetic field. The ion backflow fraction was measured to be 5% and reduced up to 3% at the gain of . The horizontal position distortion due to ion backflow in the gate operation was suppressed within mm at the beam rates up to cps/cm. On the other hand, the distortion with the gate open was measured to be mm. The distortion in the final experiment is estimated to be mm.