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Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.
Hamon, 34(2), p.50 - 53, 2024/05
Spin-contrast-variation (SCV) small-angle neutron scattering (SANS) enabled us to determine structure of nano-ice crystals that were generated in rapidly frozen sugar solution. In the frozen glucose solution, we found that the nano-ice crystals formed a planar structure with a radius larger than several tens of nanometers and a thickness of 2-3 nm, which was close to the critical nucleation size of ice crystals in supercooled water. This result suggests that the glucose molecules were preferentially bound to a specific face of nano-ice crystals, and then blocked the crystal growth perpendicular to that face.
O/HO vapor generator for contrast-variation neutron scatteringArima-Osonoi, Hiroshi*; Takata, Shinichi; Kasai, Satoshi*; Ouchi, Keiichi*; Morikawa, Toshiaki*; Miyata, Noboru*; Miyazaki, Tsukasa*; Aoki, Hiroyuki; Iwase, Hiroki*; Hiroi, Kosuke; et al.
Journal of Applied Crystallography, 56(6), p.1802 - 1812, 2023/12
Times Cited Count：6 Percentile：81.06(Chemistry, Multidisciplinary)Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.
Journal of Physical Chemistry Letters (Internet), 14(34), p.7638 - 7643, 2023/08
Times Cited Count：0 Percentile：0.00(Chemistry, Physical)The structure of nano-ice crystals in rapidly frozen glucose solution was elucidated by using spin-contrast-variation small-angle neutron scattering, which distinguishes the nano-ice crystal signal from the frozen amorphous solution signal by the polarization-dependent neutron scattering. The analysis revealed that the nano-ice crystals form a planar structure with a diameter exceeding tens of nanometers and a thickness of 1 nm, which is close to the critical nucleation size. This result suggests that the glucose molecules are preferentially bound to a specific face of nano-ice crystals, and then block the crystal growth perpendicular to that face.
Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; et al.
Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04
Times Cited Count：1 Percentile：13.05(Chemistry, Multidisciplinary)We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.
Harada, Masahide; Sekijima, Mitsuaki*; Morikawa, Noriyuki*; Masuda, Shiho; Kinoshita, Hidetaka; Sakai, Kenji; Kai, Tetsuya; Kasugai, Yoshimi; Muto, Giichi*; Suzuki, Akio*; et al.
JPS Conference Proceedings (Internet), 33, p.011099_1 - 011099_6, 2021/03
In MLF at J-PARC, a unified mercury radioactivity monitor (UHAM) is installed to find an indication of failure of the mercury target and loop system by detecting radioactive materials leaked from the system with a 
-ray energy analysis with Germanium semi-conductor detectors (Ge detectors). It is composed of three units of sampling port and radiation monitors: (1) HAM for interstitial helium gas layer between the mercury vessel and surrounding water shroud of the mercury target, (2) CAM for atmosphere in the hot cell where the target loop is operated and (3) VAM for helium gas in the helium vessel where the target vessel is installed. Once any leakages of radioactive materials are detected, an alarm signal is issued immediately to the accelerator control system to stop beam operation. Software and hardware have been upgraded yearly. For example, two Ge detectors are used for HAM for redundancy, NaI Scintillation detectors are also used as supplemental for the Ge detector to keep availability of the system for high counting rate event. In April 2015, the UHAM activated when a small water coolant leakage from the water shroud of the mercury target occurred. VAM detected an abnormal increase of the counting rate in the helium vessel. It was also indicated that the measured radioactive nuclides were generated from the activation of the coolant (water) in the water shroud and not from the mercury.
Mo-
Tc production process by (n,) reaction with irradiated high-density MoO
pelletsTsuchiya, Kunihiko; Nishikata, Kaori; Tanase, Masakazu*; Shiina, Takayuki*; Ota, Akio*; Kobayashi, Masaaki*; Yamamoto, Asaki*; Morikawa, Yasumasa*; Takeuchi, Nobuhiro*; Kaminaga, Masanori; et al.
Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 9 Pages, 2013/10
no abstracts in English
Makihara, Akiko*; Yokose, Tamotsu*; Tsuchiya, Yoshihisa*; Miyazaki, Yoshio*; Abe, Hiroshi; Shindo, Hiroyuki*; Ebihara, Tsukasa*; Maru, Akifumi*; Morikawa, Koichi*; Kuboyama, Satoshi*; et al.
IEEE Transactions on Nuclear Science, 60(1), p.230 - 235, 2013/02
Times Cited Count：6 Percentile：41.53(Engineering, Electrical & Electronic)no abstracts in English
Makihara, Akiko*; Yokose, Tamotsu*; Tsuchiya, Yoshihisa*; Tani, Koichi*; Morimura, Tadaaki*; Abe, Hiroshi; Shindo, Hiroyuki*; Ebihara, Tsukasa*; Maru, Akifumi*; Morikawa, Koichi*; et al.
Proceedings of 10th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-10) (Internet), p.119 - 122, 2012/12
no abstracts in English
Okutsu, Kazuo*; Morikawa, Seiji*; Shimbo, Hiroshi*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Murakami, Takeshi*; Aoyama, Yuji*
JNC TJ8400 2005-013, 117 Pages, 2005/02
JNC-TJ8400-2005-013.pdf:3.24MB
To integrate the system for evaluation of long-term hydraulic condition in near field of TRU waste disposal, the engineered barrier, which consists of bentonite buffer and cementitious materials, was employed in the series of laboratory tests. On the bentonite buffer, with the aim of investigating of the effect of (i) interlayer cation in bentonite, (ii) content of siliceous sand and (iii) the ionic strength of ground water on its mechanical and hydraulic properties, series of laboratory tests were conducted. The same lot of bentonite was used in the series of tests to obtain consistent data. In addition, the swelling test of the laminated bentonite with caliumization front was conducted for verification of the proposed constitutive model. On cementitious materials, the altered specimen that produced immersing was investigated the water permeation and also characteristics. The hardened cement paste specimens with W/C=40 to 105% were immersed into deionized water and alteration behavior under diffusion condition was investigated.
Okutsu, Kazuo*; Morikawa, Seiji*; Shimbo, Hiroshi*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Murakami, Takeshi*; Aoyama, Yuji*
JNC TJ8400 2005-012, 272 Pages, 2005/02
JNC-TJ8400-2005-012.pdf:7.05MB
To integrate the system for evaluation of long-term hydraulic condition in near field of TRU waste disposal, the engineered barrier, which consists of bentonite buffer and cementitious materials, was employed in the series of laboratory tests.On the bentonite buffer, with the aim of investigating of the effect of (i)interlayer cation in bentonite, (ii)content of siliceous sand and (iii)the ionic strength of ground water on its mechanical and hydraulic properties, series of laboratory tests were conducted. The same lot of bentonite was used in the series of tests to obtain consistent data. In addition, the swelling test of the laminated bentonite with caliumization front was conducted for verification of the proposed constitutive model.On cementitious materials, the altered specimen that produced immersing was investigated the water permeation and also characteristics. The hardened cement paste specimens with W/C=40 to 105% were immersed into deionized water and alteration behavior under diffusion condition was investigated.
Morikawa, Hiroshi*; Kurata, Hiroki; Fujita, Miya*
Journal of Electron Microscopy, 49(1), p.67 - 72, 2000/04
Times Cited Count：12 Percentile：52.57(Microscopy)no abstracts in English
Yamada, Toshiro*; Morikawa, Hiroshi*; Ishida, Masatoshi*; Seto, Yutaka*; Yamamoto, Yoshifumi*; Sawamoto, Yoshikazu*
JNC TJ8410 98-002, 124 Pages, 1998/11
On the 11st of March 1997, a fire and explosion occurred in a Bituminization Demonstraion Facility. It subsequently became necessary to estimate the explosive force of this event. To this end, this report evaluates the static yield and ultimate strength of the main structural walls and floors of this facility. A simple method and a Finite Element Method (FEM) were considered to evaluate the yield and ultimate strength of reinforced concrete (RC) slabs. Using the simple method, the yield strength can be estimated effectively by solution of fundamental differential equations. The ultimate strength of RC slabs is tried to estimate using a modified yield line theory which is taken an arch effect created within RC slabs into account. However, this method is difficult to apply to slabs with complicated boundary conditions. In this case, FEM is necessary. The validity of the simple method is verified by analyzing some slabs using both methods and comparing the results. Previous experimental results and some RC slabs in the Asphalt Bituminization Facility were evaluated on the basis of yield and ultimate strength using both methods, and the validity of both methods were verified. Especially, in simulating previous experiments, the error in the estimated values of the ultimate strength using simple method to experimental values were within 30%. The estimated values of the ultimate strength using the FEM were 15% larger than the experimental values. As a result, the simple method taking arch effect into account was verified to some extent.
26, 1994, Tokai, JapanOshima, Masumi; Morikawa, Tsuneyasu*; ; Ishii, Tetsuro; ; Ikezoe, Hiroshi
JAERI-Conf 95-004, 103 Pages, 1995/03
no abstracts in English
Seino, Hiroshi; Miyake, Osamu; Morikawa, Satoshi; Himeno, Yoshiaki
PNC TN9410 91-025, 12 Pages, 1990/01
Evaluation of the aerosol behavior is esential in the safety analyses of the LMFBRs. This is because, in the case of a sodium leak accident, radioactive materialscould be released to the containment atmosphere, and they would behave together with the sodium aerosols during the accidents. From 1988 to 1989, PNC participatedin the Second International Sodium Aerosol Code Benchmark Study performed underthe auspices of the Commission of EC inan attempt to validate the aerosol behavior module of the CONTAIN code. The other organizations participating in the study are CEA-France, KfK-W. Germany and UKAEA-U.K. This paper describes an outline ofthe comparison between the test resultsand the calculational results made by PNC, whereas the international comparison is presented separately(Ref.1). Results revealed that the suspended aerosol mass concentration and the aerodynamic mass median diameter obtained from both the pre - and post - test calculations agreed fairly well with the test results.
Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; Arima, Hiroshi*; Yamada, Takeshi*
no journal, ,
The small- and wide-angle neutron scattering instrument (TAIKAN) was installed in the Materials and Life Science Experimental Facility (MLF) of J-PARC, which was designed for efficient measurement in the range from sub-nanometre to micrometre scale. Therefor, TAIKAN is used in various research fields. Recently, the morphology of ion exchange membranes for fuel cells have been much studied using SAXS and WAXS techniques under high-temperature and high-humidity conditions close to the product usage environment. In this study, we measured the humidity dependence of the Nafion film structure at 80
C using a Humidity Cell at BL15 TAIKAN. As a result, it was possible to measure the humidity dependence of the matrix, ionomer, and crystal phase in the film. In this presentation, we will report the details of those results, and also report on the development status of TAIKAN.
Mo/
Tc production using irradiated MoO pelletsNishikata, Kaori; Kimura, Akihiro; Shiina, Takayuki*; Yamamoto, Asaki*; Ishida, Takuya; Ota, Akio*; Tanase, Masakazu*; Takeuchi, Nobuhiro*; Morikawa, Yasumasa*; Kobayashi, Masaaki*; et al.
no journal, ,
JP, 2011-173260 Patent publication (In Japanese)
no abstracts in English
Mo-Tc domestic production with high-density MoO pellets by (n,) reactionTsuchiya, Kunihiko; Tanase, Masakazu*; Shiina, Takayuki*; Ota, Akio*; Kobayashi, Masaaki*; Morikawa, Yasumasa*; Yamamoto, Asaki*; Kaminaga, Masanori; Kawamura, Hiroshi
no journal, ,
no abstracts in English
Watanabe, Masao; Oku, Takayuki; Kawamura, Seiko; Takata, Shinichi; Su, Y. H.; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ishikado, Motoyuki*; Sakaguchi, Yoshifumi*; et al.
no journal, ,
At Material Life Science Laboratory (MLF) in J-PARC, each beamline (BL) has standard sample environment (SE) equipment, while our SE team is organized to maintain BL common sample environment equipment and support the users. We have expensive equipment that is not frequently used but indispensable, and that requires specialized knowledge and skills for operation as BL common SE equipment. The SE team has sub-teams as;(1) cryo & magnet, (2) high temperature, (3) stress (high pressure, tension and fatigue machine), (4) soft matter, (5) humidity, (6) special environment (pulsed magnet, light irradiation and computation). In this presentation, we will explain the current status of BL common sample environment equipment.
Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke*; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.
no journal, ,
The structure of nano-ice crystals in rapidly frozen sugar solution was elucidated by using spin-contrast-variation small-angle neutron scattering, which distinguishes the nano-ice crystal signal from the frozen amorphous solution signal by the polarization-dependent neutron scattering. The analysis revealed that the nano-ice crystals form a planar structure with a diameter exceeding tens of nanometers and a thickness of 1 nm, which is close to the critical nucleation size. This result suggests that the sugar molecules are preferentially bound to a specific face of nano-ice crystals, and then block the crystal growth perpendicular to that face.
