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Teshigawara, Makoto; Lee, Y.*; Tatsumoto, Hideki*; Hartl, M.*; Aso, Tomokazu; Iverson, E. B.*; Ariyoshi, Gen; Ikeda, Yujiro*; Hasegawa, Takumi*
Nuclear Instruments and Methods in Physics Research B, 557, p.165534_1 - 165534_10, 2024/12
Times Cited Count：1 Percentile：0.00(Instruments & Instrumentation)At Japanese Spallation Neutron Source in J-PARC, the para-hydrogen fraction was measured by using Raman spectroscopy in-situ for an integrated beam power of 9.4 MW
h at 1 MW operation, to evaluate the functionality of the ferric oxyhydroxide catalyst. This result showed that full functionality of the catalyst was retained up to the 1 MW operation. We attempted to study the effect of neutron scattering driven para to ortho-hydrogen back-conversion rate in the absence of the catalyst effect with a bypass line without catalyst. The measured increase of ortho-hydrogen fraction was 0.44% for an integrated beam power of 2.4 MWh at 500 kW operation, however, which was considered to be due to not only to neutron collisions in cold moderators but also to the high ortho-hydrogen fraction of initially static liquid hydrogen in the bypass line and passive exudation of quasi-static hydrogen in the catalyst vessel to the main loop.
Watanabe, Kenichi*; Sugai, Yusuke*; Hasegawa, Sota*; Tanaka, Seishiro*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Shinohara, Takenao; Su, Y. H.; Parker, J. D.*; Kockelmann, W.*
Scientific Reports (Internet), 14, p.25224_1 - 25224_13, 2024/10
Times Cited Count：0 Percentile：0.00(Multidisciplinary Sciences)Watanabe, Kenichi*; Sugai, Yusuke*; Hasegawa, Sota*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Shinohara, Takenao; Su, Y. H.; Parker, J. D.*; Kockelmann, W.*
Sensors and Materials, 36(1), p.149 - 154, 2024/01
Times Cited Count：2 Percentile：62.29(Instruments & Instrumentation)Hasegawa, Kunio; Li, Y.; Udyawar, A.*; Lacroix, V.*
International Journal of Pressure Vessels and Piping, 204, p.104952_1 - 104952_7, 2023/08
Times Cited Count：2 Percentile：20.09(Engineering, Multidisciplinary)When axial cracks were detected in pipes, failure stresses for high toughness pipes are estimated using the Limit Load Criteria. The allowable stresses for the cracked pipes are derived from the combination of the failure stresses and safety factors. The allowable sizes of crack depths and lengths are determined from the allowable stresses. From the comparison of the allowable and failure stresses for through-wall cracks, the allowable cracks are not uniform. They can be separated into three different characteristics, i) leak-before-break (LBB) and crack growth stability, ii) non-LBB and crack growth stability and iii) non-LBB and crack growth instability. Inspectors and users should pay special attention to allowable cracks with the third characteristic to prevent unexpected failure, particularly for thin-wall pipes. The allowable crack depths and lengths that require special attention can be expressed by appropriate equations.
Hasegawa, Kunio; Strnadel, B.*; Li, Y.; Lacroix, V.*
Journal of Pressure Vessel Technology, 144(6), p.061202_1 - 061202_6, 2022/12
Times Cited Count：2 Percentile：17.22(Engineering, Mechanical)When pipe walls are thin, part-through flaws are easily develop into through-wall flaws, and the likelihood of coolant leakage is high. The ASEM Code Section XI provides final allowable flaw angles of through-wall flaw for thin-wall pipes. The final allowable angles are applied to pipes in order to maintain structural integrity if the part-through flaws become through-wall flaws. To ensure that this stability is compromised, plastic collapse stresses for through-wall flaws are combined with allowable stresses. However, the final allowable angles of through-wall flaws are not identified for thin-walled pipes. This paper compares plastic collapse stresses of through-wall flaws and allowable stresses of part-through flaws for pipes. The comparison of these stresses is used to derive the final allowable angles of through-wall flaws. The angles can be expressed either in the form of exact solutions or as conventional options that are appropriate for various service level conditions.
Hasegawa, Kunio; Li, Y.; Strnadel, B.*; Udyawar, A.*
Journal of Pressure Vessel Technology, 144(5), p.051305_1 - 051305_6, 2022/10
Times Cited Count：1 Percentile：8.34(Engineering, Mechanical)Fully plastic collapse stresses for circumferentially part-through cracked pipes subjected to bending stresses are estimated by Limit Load Criteria provided by the ASME Code Section XI. Allowable crack depths were determined by using the Limit Load Criteria and that are tabulated in the ASME Code Section XI for different plant service level conditions. On the other hand, crack penetration bending stresses for part-through cracked pipes were estimated by using the Local Approach of Limit Load Criteria. By using these Criteria, the study presented in this paper obtained allowable crack depths at penetration for circumferentially part-through cracked pipes. Comparing the allowable crack depths obtained by both methods for each service level, it is evident that the allowable crack depths at penetration calculated by the Local Approach of Limit Load Criteria are almost always smaller than those at fully plastic collapse stresses calculated by the Limit Load Criteria. It was found that the allowable crack depths provided by the ASME Code Section XI are less conservative for crack penetrations.
Yamaguchi, Yoshihito; Hasegawa, Kunio; Li, Y.; Lacroix, V.*
Proceedings of ASME 2022 Pressure Vessels and Piping Conference (PVP 2022) (Internet), 4 Pages, 2022/07
Lacroix, V.*; Hasegawa, Kunio; Li, Y.; Yamaguchi, Yoshihito
Proceedings of ASME 2022 Pressure Vessels and Piping Conference (PVP 2022) (Internet), 7 Pages, 2022/07
Hasegawa, Kunio*; Dvo
k, D.*; Mare
, V.*; Strnadel, B.*; Li, Y.
Journal of Pressure Vessel Technology, 144(1), p.011303_1 - 011303_6, 2022/02
Times Cited Count：5 Percentile：40.91(Engineering, Mechanical)Fully plastic failure stress for circumferentially surface-cracked pipe subjected to tensile loading can be estimated by means of limit load criterion (LLC) based on the net-section stress approach. LLC of the first type (labelled LLC-1) was derived from the balance of uniaxial forces. LLC of the second type, derived from the balance of bending moments and axial forces (labelled LLC-2), is adopted in Section XI of the ASME (American Society of Mechanical Engineering) Code. From the literature survey of experimental data, failure stresses obtained by both types of LLCs were compared with the experimental data. It can be stated that failure stresses calculated by LLC-1 are better than those calculated by LLC-2 for shallow cracks. On the contrary, for deep cracks, LLC-2 predictions of failure stresses are fairly close to the experimental data. It can be stated that the allowable cracks given in Section XI of the ASME Code are conservative.
-Orbital component in the Borromean nucleus 
BYang, 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
Times Cited Count：61 Percentile：95.90(Physics, Multidisciplinary)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.
Yamaguchi, Yoshihito; Hasegawa, Kunio; Li, Y.
Journal of Pressure Vessel Technology, 142(4), p.041507_1 - 041507_6, 2020/08
Times Cited Count：1 Percentile：5.70(Engineering, Mechanical)The phenomenon of crack closure is important in the prediction of fatigue crack growth. Several experimental data indicate the closing of fatigue cracks both under negative and positive loads at constant amplitude loading cycles, depending on the magnitude of stress amplitude and stress ratio. Appendix A-4300 of the ASME Code Section XI provides two equations of fatigue crack growth rates expressed by the stress intensity factor range for ferritic steels under negative stress ratio. The boundary of two fatigue crack growth rates is classified with the magnitude of applied stress intensity factor range, in consideration of the crack closure. The boundary value provided by the ASME Code Section XI is validated in this study through an investigation of the influence of the magnitude of the applied stress intensity factor range on crack closure, with the application of fatigue crack growth tests using ferritic steel specimens in air environment at room and high temperatures. Crack closures are obtained as a parameter of stress ratio, and herein, were found to occur at a smaller applied stress intensity factor range, as opposed to the definition given by Appendix A-4300.
Hasegawa, Kunio; Li, Y.; Lacroix, V.*; Mare, V.*
Proceedings of ASME 2020 Pressure Vessels and Piping Conference (PVP 2020) (Internet), 6 Pages, 2020/08
Authors have developed more precise equations using the Limit Load Criteria, which is called Modified Limit Load Criteria, hereafter. As the results of the Modified Limit Load Criteria, failure stresses for external flawed pipes are always smaller than the failure stresses obtained by the Limit Load Criteria provided by the ASME Code Section XI. It seems that the allowable flaw sizes of the Acceptance Standards provided by the ASME Code Section XI are less conservative for external flaws. The objective of this paper is to demonstrate difference of failure stresses by the Limit Load Criteria and Modified Limit Load Criteria for external flawed pipes. In addition, the allowable flaws of the Acceptance Standards are examined by large and small diameter pipes with external flaws using the Modified Limit Load Criteria.
Hasegawa, Kunio; Li, Y.; Lacroix, V.*; Mare, V.*
Journal of Pressure Vessel Technology, 142(3), p.031506_1 - 031506_7, 2020/06
Times Cited Count：1 Percentile：5.70(Engineering, Mechanical)Bending stress at plastic collapse for a circumferentially cracked pipe is predicted by limit load criterion provided by the Appendix C of the ASME Code Section XI. The equation of the Appendix C is applicable for pipes with both external and internal surface cracks. On the other hand, the authors have developed a more precise equation. From the comparison of Appendix C equation and the new equation, the plastic collapse stress estimated by the Appendix C equation gives less conservative bending capacity prediction for external cracked pipes with thick wall thickness and large crack angle. This paper discusses the limitation scope to use the limit load criterion of the Appendix C equation.
Hasegawa, Kunio; Li, Y.; Lacroix, V.*; Mare, V.*
Proceedings of 2019 ASME Pressure Vessels and Piping Conference (PVP 2019) (Internet), 8 Pages, 2019/07
Bending stress at plastic collapse for a circumstantially cracked pipe is predicted by limit load equation provided by the Appendix C of the ASME Code Section XI. The equation of the Appendix C is applicable for pipes with both external and internal surface cracks. On the other hand, authors had developed an equation taking into account the pipe mean radii at non-cracked area and at cracked ligament area. From the comparison of Appendix C equation and the new equation, the plastic collapse stress estimated by the Appendix C equation gives 20 to 30% less conservative for external cracked pipes with small 
, where 
is the pipe mean radius and t is the pipe wall thickness. This paper discusses the limitation of the use of for the Appendix C equation.
Hasegawa, Kunio; Li, Y.; Kim, Y.-J.*; Lacroix, V.*; Strnadel, B.*
Journal of Pressure Vessel Technology, 141(3), p.031201_1 - 031201_5, 2019/06
Times Cited Count：1 Percentile：4.80(Engineering, Mechanical)When discrete multiple flaws are in the same plane, and they are close to each other, it can be determined whether they are combined or standalone in accordance with combination rules provided by Fitness-For-Service (FFS) codes. However, specific criteria of the rules are different amongst these FFS codes. On the other hand, plastic collapse bending stresses for stainless steel pipes with two circumferential similar flaws were obtained by experiments and the prediction procedure for collapse stresses for pipes with two similar flaws were developed analytically. Using the experimental data and the analytical procedure, plastic collapse stresses for pipes with two similar flaws are compared with the stresses in compliance with the flaw combination criteria. It is shown that the calculated plastic collapse stresses based on the flaw combination criteria are significantly different from the experimental and analytical stresses.
Abe, Mitsushi*; Bae, S.*; Beer, G.*; Bunce, G.*; Choi, H.*; Choi, S.*; Chung, M.*; da Silva, W.*; Eidelman, S.*; Finger, M.*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(5), p.053C02_1 - 053C02_22, 2019/05
Times Cited Count：161 Percentile：99.30(Physics, Multidisciplinary)This paper introduces a new approach to measure the muon magnetic moment anomaly 
and the muon electric dipole moment (EDM) 
at the J-PARC muon facility. The goal of our experiment is to measure 
and using an independent method with a factor of 10 lower muon momentum, and a factor of 20 smaller diameter storage-ring solenoid compared with previous and ongoing muon g-2 experiments with unprecedented quality of the storage magnetic field. Additional significant differences from the present experimental method include a factor of 1000 smaller transverse emittance of the muon beam (reaccelerated thermal muon beam), its efficient vertical injection into the solenoid, and tracking each decay positron from muon decay to obtain its momentum vector. The precision goal for is a statistical uncertainty of 450 parts per billion (ppb), similar to the present experimental uncertainty, and a systematic uncertainty less than 70 ppb. The goal for EDM is a sensitivity of 
ecm.
Mare, V.*; Hasegawa, Kunio; Li, Y.; Lacroix, V.*
Journal of Pressure Vessel Technology, 141(2), p.021203_1 - 021203_6, 2019/04
Times Cited Count：6 Percentile：28.27(Engineering, Mechanical)Appendix C-5320 of ASME BPV Code Section XI provides an equation of bending stress at the plastic collapse, where the equation is applicable for both inner and outer surface cracks. That is, the collapse stresses for pipes with inner and outer surface cracks are the same. Authors considered the separated pipe mean radii at the cracked ligament and at the un-cracked ligament and equations of plastic collapse stresses for both inner and outer cracked pipes were developed. As the results of the calculations, when the crack angle and depth are the same, the collapse stress for outer cracked pipe is lower than that calculated by the Appendix C equation. It is found that the Appendix C equation gives un-conservative plastic collapse stress.
Li, Y.; Azuma, Kisaburo*; Hasegawa, Kunio
International Journal of Pressure Vessels and Piping, 171, p.305 - 310, 2019/03
Times Cited Count：4 Percentile：31.46(Engineering, Multidisciplinary)Hasegawa, Kunio*; Strnadel, B.*; Li, Y.; Lacroix, V.*
Journal of Pressure Vessel Technology, 140(5), p.051204_1 - 051204_7, 2018/10
Times Cited Count：0 Percentile：0.00(Engineering, Mechanical)Hasegawa, Kunio; Li, Y.; Kim, Y.-J.*; Lacroix, V.*; Bohumir, S.*
Proceedings of 2018 ASME Pressure Vessels and Piping Conference (PVP 2018), 6 Pages, 2018/07
When discrete multiple flaws are close to each other, it is determined whether they are combined or standalone in accordance with combination rules provided by fitness-for-service codes. However, specific criteria of the rules are different. On the other hand, plastic collapse bending stresses for stainless steel pipes with circumferential twin flaws were obtained by experiments. Using the experimental data and the analytical procedure, plastic collapse stresses for pipes with twin flaws are compared with the stresses in compliance with the combination criteria. It is shown that the calculated plastic collapse stresses based on the combination criteria are significantly different from the experimental and analytical stresses.
