Refine your search:     
Report No.
Search Results: Records 1-20 displayed on this page of 52

Presentation/Publication Type

Initialising ...


Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...


Initialising ...


Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Benchmark analysis of ductile fracture simulation for circumferentially cracked pipes subjected to bending

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

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.

Journal Articles

How different is the core of $$^{25}$$F from $$^{24}$$O$$_{g.s.}$$ ?

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:9 Percentile:88.96(Physics, Multidisciplinary)

The structure of a neutron-rich $$^{25}$$F nucleus is investigated by a quasifree ($$p,2p$$) knockout reaction. The sum of spectroscopic factors of $$pi 0d_{5/2}$$ orbital is found to be 1.0 $$pm$$ 0.3. The result shows that the $$^{24}$$O core of $$^{25}$$F nucleus significantly differs from a free $$^{24}$$O nucleus, and the core consists of $$sim$$35% $$^{24}$$O$$_{rm g.s.}$$, and $$sim$$65% excited $$^{24}$$O. The result shows that the $$^{24}$$O core of $$^{25}$$F nucleus significantly differs from a free $$^{24}$$O nucleus. The result may infer that the addition of the $$0d_{5/2}$$ proton considerably changes the neutron structure in $$^{25}$$F from that in $$^{24}$$O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Journal Articles

Development of TPC Trigger Hodoscope for J-PARC E42/E45 hadron experiment

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

Journal Articles

Measurement of radiative decay of $$Lambda$$(1405) by using hyperon spectrometer at J-PARC

Hwang, S.; Imai, Kenichi

JPS Conference Proceedings (Internet), 17, p.033010_1 - 033010_2, 2017/07

Journal Articles

$$gamma$$-ray spectroscopy of hypernuclei; Recent results and prospect at J-PARC

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

Journal Articles

Search for excited state of $$Sigma$$ hypernucleus in the J-PARC E13 experiment

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

Journal Articles

The First gamma-ray spectroscopic study of $$sd$$-shell hypernucleus, $$^{19}_{Lambda}$$F

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

Journal Articles

Baryon spectroscopy in $$(pi,2pi)$$ reactions with 10$$^{6}$$Hz pion beams at J-PARC

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), 5 Pages, 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 $$(pi,2pi)$$ reactions to these baryon resonances. However, there are only 240 thousand events of $$(pi, 2pi)$$ reaction data measured in 1970's. Thus, we proposed an experiment E45 to study baryon resonances in $$(pi,2pi)$$ reaction utilizing $$10^6$$ Hz $$pi$$ 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.

Journal Articles

Studies of high density baryon matter with high intensity heavy-ion beams at J-PARC

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:11 Percentile:71(Physics, Nuclear)

Journal Articles

Observation of spin-dependent charge symmetry breaking in $$Lambda N$$ interaction; $$gamma$$-ray spectroscopy of $$^4_{Lambda}$$He

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:54 Percentile:92.84(Physics, Multidisciplinary)

Journal Articles

Cosmic-ray test of a time-of-flight detector for double-strangeness experiments at J-PARC

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:3 Percentile:32.14(Instruments & Instrumentation)

Journal Articles

Development of a GEM-based TPC for H-dibaryon search at J-PARC

Sako, Hiroyuki; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sato, Susumu; Sugimura, Hitoshi

Proceedings of Science (Internet), 4 Pages, 2015/05

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 $$pm$$0.2 mm due to ion backflow.

Journal Articles

Backward-angle photoproduction of $$omega$$ and $$eta'$$ mesons from protons in the photon energy range from 1.5 to 3.0 GeV

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:7 Percentile:54.9(Physics, Multidisciplinary)

Journal Articles

Development of a prototype GEM TPC with a gating grid for an H-dibaryon search experiment at J-PARC

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:43.74(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$$_{4}$$ (90:10) and Ar-CF$$_{4}$$ (95:5), where the former is mainly used. The detection efficiency was measured to be 98% at the beam rate up to $$5times10^{5}$$ cps/cm$$^{2}$$, and 90% at the rate of $$3times10^{6}$$ cps/cm$$^{2}$$. 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 $$1.6times10^{4}$$. The horizontal position distortion due to ion backflow in the gate operation was suppressed within $$pm 0.2$$ mm at the beam rates up to $$5times10^{5}$$ cps/cm$$^{2}$$. On the other hand, the distortion with the gate open was measured to be $$pm2$$ mm. The distortion in the final experiment is estimated to be $$0.3 pm 0.2$$ mm.

Journal Articles

Analysis on effects of transverse electric field in an injector cavity of compact-ERL at KEK

Hwang, J.-G.*; Kim, E.-S.*; Miyajima, Tsukasa*; Honda, Yosuke*; Harada, Kentaro*; Shimada, Miho*; Takai, Ryota*; Kume, Tatsuya*; Nagahashi, Shinya*; Obina, Takashi*; et al.

Nuclear Instruments and Methods in Physics Research A, 753, p.97 - 104, 2014/07

 Times Cited Count:7 Percentile:50.1(Instruments & Instrumentation)

Journal Articles

Development of a GEM-TPC for H-dibaryon search experiment at J-PARC

Sako, Hiroyuki; Ahn, J. K.*; Baek, K. H.*; Bassalleck, B.*; Fujioka, H.*; Guo, L.*; Hasegawa, Shoichi; Hicks, K.*; Honda, R.*; Hwang, S. H.*; et al.

Journal of Instrumentation (Internet), 9(4), p.C04009_1 - C04009_10, 2014/04

 Times Cited Count:3 Percentile:18.85(Instruments & Instrumentation)

A TPC has been developed for J-PARC E42 experiment to search for H-dibaryon in ($$K^-$$, $$K^+$$) reaction. An event with 2 $$pi^-$$ and 2 protons decaying from H-dibaryon is searched for inside the TPC. The TPC has octagonal prism shape drift volume with about 50 cm diameter with 55 cm drift length filled with Ar-CH$$_{4}$$ (90:10) gas. At the end of the drift volume, 3-layer GEMs are equipped. In order to analyze momenta of produced particles, the TPC is applied with 1 T dipole magnetic field parallel to the drift electric field with a superconducting Helmholz magnet. In order to maximize the acceptance of H-dibaryon events, a diamond target is installed inside the TPC drift volume, in a cylindrical hole opened from the top to the middle of the drift volume. Since extremely high-rate $$K^-$$ beam is directly injected into the TPC drift volume to the target, a gating grid and GEMs are adopted to suppress positive-ion feedback.

Journal Articles

Search for $$^6_{Lambda}$$H hypernucleus by the $$^{6}$$Li($$pi^-,K^+$$) reaction at $$p_pi$$- = 1.2 GeV/$$c$$

Sugimura, Hitoshi; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Kiuchi, Ryuta; Ichikawa, Yudai; Hwang, S. H.*; Hasegawa, Shoichi; Tanida, Kiyoshi; J-PARC E10 Collaboration*

Physics Letters B, 729, p.39 - 44, 2014/02

 Times Cited Count:28 Percentile:88.47(Astronomy & Astrophysics)

We have carried out an experiment to search for a neutron-rich hypernucleus, $$^6_Lambda$$H, by the $$^{6}$$Li($$pi$$$$^{-}$$,K$$^{+}$$) reaction at p$$_{pi-}$$ = 1.2 GeV/c. The obtained missing-mass spectrum with an estimated energy resolution of 3.2 MeV (FWHM) showed no peak structure corresponding to the $$^6_Lambda$$H hypernucleus neither below nor above the $$^4_Lambda$$H+2n particle decay threshold. An upper limit of the production cross section for the bound $$^6_Lambda$$H hypernucleus was estimated to be 1.2 nb/sr at 90% confidence level.

Journal Articles

Search for the $$K^-pp$$ bound state via $$gamma d rightarrow K^+pi^- X$$ reaction at $$E_{gamma}$$ = 1.5 - 2.4 GeV

Tokiyasu, Atsushi*; Imai, Kenichi; Hwang, S. H.*; LEPS Collaboration*

Physics Letters B, 728, p.616 - 621, 2014/01

 Times Cited Count:59 Percentile:96.71(Astronomy & Astrophysics)

Journal Articles

$$K^{ast 0}Sigma^+$$ photoproduction with evidence for the Kappa Meson Exchange at SPring-8/LEPS

Hwang, S. H.*; Hicks, K.*; Ahn, J. K.*; Nakano, Takashi*

Few-Body Systems, 54(7-10), p.1037 - 1041, 2013/08

 Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)

Journal Articles

Spin-density matrix elements for $$gamma p rightarrow K^{*0} Sigma^+$$ at $$E_{gamma} = 1.85 - 3.0$$ GeV with evidence for $$kappa (800)$$ meson exchange

Imai, Kenichi; Hwang, S. H.*; Hicks, K.*; LEPS Collaboration*

Physical Review Letters, 108(9), p.092001_1 - 092001_5, 2012/03

 Times Cited Count:19 Percentile:72.48(Physics, Multidisciplinary)

The exclusive reaction $$gamma p rightarrow K^{*0} Sigma^+ $$ was measured using lineraly polarized photon at $$E_{gamma} - 1.85 - 3.0$$ GeV. Angular distributions of the $$K^+pi^-$$ system were fitted to extract spin-density matrix elements of the $$K^{*0}$$ decay. The measured parity asymmetry shows that natural parity exchange is dominant in this reaction. This result clearly indicates the need for $$t$$-channel exchange of the $$kappa (800)$$ scalar exchange.

52 (Records 1-20 displayed on this page)