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Journal Articles

Observation of surface modification of multi-layered mirror induced by soft X-ray laser pulse

Nishikino, Masaharu; Ishino, Masahiko; Ichimaru, Satoshi*; Hatayama, Masatoshi*; Hasegawa, Noboru; Kawachi, Tetsuya

Reza Gakkai Dai-483-Kai Kenkyukai Hokoku; Tanhacho Ryoshi Bimu Hassei To Sono Oyo, p.25 - 28, 2015/12

X-ray ablation has been recently achieved using plasma soft X-ray lasers (SXRLs), laser plasma soft X-rays, and X-ray free electron lasers. In order to study the interactions between picosecond SXRL beams and material and multi-layered structure surfaces were irradiated with SXRL pulse. Following irradiation, the substrate surface was observed using a scanning electron microscope and an atomic force microscope. The surface modifications caused by the SXRL beam were clearly seen. The multi-layered mirror is the important component for the EUV lithography. Then, we have started the damage test of multi-layered structure, and the surface modifications caused by the SXRL pulse irradiations were confirmed.

JAEA Reports

Influence of Great East Japan Earthquake on neutron source station in J-PARC

Sakai, Kenji; Sakamoto, Shinichi; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Naoe, Takashi; Kasugai, Yoshimi; Tatsumoto, Hideki; et al.

JAEA-Technology 2011-039, 121 Pages, 2012/03

JAEA-Technology-2011-039.pdf:10.87MB

This report investigates the behavior, damage and restoration of a neutron source station of the MLF at the Great East Japan Earthquake and verified the safety design for emergency accidents in the neutron source station. In the MLF, after an occurrence of the Earthquake, strong quakes were detected at the instruments, the external power supply was lost, all of the circulators shut down automatically, and the hydrogen gas was released. The leakages of mercury, hydrogen and radio-activation gases did not occur. While, the quakes made gaps between the shield blocks and ruptured external pipe lines by subsidence around the building. But significant damages to the components were not found though the pressure drop of compressed air lines influenced on a target trolley lock system and so on. These results substantiated the validity of the safety design for emergency accidents in the source station, and suggested several points of improvement.

Journal Articles

Influence of Great East Japan Earthquake on neutron target station in J-PARC

Sakai, Kenji; Futakawa, Masatoshi; Takada, Hiroshi; Sakamoto, Shinichi; Maekawa, Fujio; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; et al.

Proceedings of 20th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-20) (USB Flash Drive), 6 Pages, 2012/03

This report investigates behaviors and damages of each component in a neutron target station of the MLF at the J-PARC at the time of the Great East Japan Earthquake (GEJE). At the date of the GEJE, in the MLF, strong quakes were detected at several instruments, an external power supply were lost, all of the circulation systems were shut down automatically, and a hydrogen gas was released as planned. Leakage of activation liquids and gases did not occur. While, the quakes made gaps between shield blocks and ruptured external pipe lines for air and water by subsidence. But significant damages on the components of the target station were not found though a loss of compressed air supply affected lock systems with air cylinders and pneumatic operation values. These results substantiated a validity of safety design on the target station for emergency accidents.

Journal Articles

Pressure fluctuation behavior in the cryogenic hydrogen system caused by a 100 kW proton beam injection

Tatsumoto, Hideki; Aso, Tomokazu; Otsu, Kiichi; Uehara, Toshiaki; Sakurayama, Hisashi; Kawakami, Yoshihiko; Kato, Takashi; Hasegawa, Shoichi; Futakawa, Masatoshi

AIP Conference Proceedings 1218, p.289 - 296, 2010/04

 Times Cited Count:2 Percentile:72.9

A cryogenic hydrogen system provides the supercritical hydrogen to the moderators and removes the nuclear heating at the moderators, which is estimated to 3.8 kW for a proton beam power of 1 MW. In order to mitigate pressure fluctuation caused by suddenly turning a proton beam on and off, we should design a pressure control system, which is composed of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller. In December 2007, a 109 kW proton beam was injected to the JSNS. The pressure fluctuation behaviors have been studied for the 109 kW proton beam operation. As soon as the proton beam is injected, the accumulator starts to spontaneously constrict. The heater control can succeed in maintaining a constant heat load applied to the cryogenic hydrogen system. The pressure control system can reduce the pressure fluctuation below 5 kPa. We have confirmed that the pressure control system should be effective.

Journal Articles

Heavy-ion-induced bystander killing of human lung cancer cells; Role of gap junctional intercellular communication

Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Sakurai, Hideyuki*; Hasegawa, Masatoshi*; Funayama, Tomoo; Kakizaki, Takehiko*; Kobayashi, Yasuhiko; Nakano, Takashi*

Cancer Science, 100(4), p.684 - 688, 2009/04

 Times Cited Count:54 Percentile:75.81(Oncology)

Journal Articles

Design of hydrogen vent line for the cryogenic hydrogen system in J-PARC

Tatsumoto, Hideki; Aso, Tomokazu; Kato, Takashi; Otsu, Kiichi; Hasegawa, Shoichi; Maekawa, Fujio; Futakawa, Masatoshi

Nuclear Instruments and Methods in Physics Research A, 600(1), p.269 - 271, 2009/02

 Times Cited Count:1 Percentile:12.39(Instruments & Instrumentation)

As one of the main experimental facilities in J-PARC, an intense spallation neutron source (JSNS) driven by a 1-MW proton beam selected supercritical hydrogen at the temperature of 20 K and the pressure of 1.5 MPa as a moderator material. A cryogenic hydrogen system plays a role in cooling the moderators. For safety reasons, we have designed a hydrogen relief system that can release hydrogen to the outside safely, even if some off-normal events occur. The design of the hydrogen vent line should be considered to prevent the cryogenic hydrogen from freezing purge nitrogen gas in the vent line and freezing moisture in the stack placed in an outdoor location, and to inhibit the piping temperature drop at the building wall penetration. In this work, the temperature change behaviors in the hydrogen vent line were analyzed by using a CFD code, STAR-CD. We determined the required sizes of the vent line based on the analytical results and its layout in the building.

Journal Articles

Performance test of a helium refrigerator for the cryogenic hydrogen system in J-PARC

Tatsumoto, Hideki; Aso, Tomokazu; Kato, Takashi; Otsu, Kiichi; Hasegawa, Shoichi; Maekawa, Fujio; Futakawa, Masatoshi

Proceedings of International Cryogenic Engineering Conference 22 (ICEC-22) and International Cryogenic Materials Conference 20 (ICMC 2008), p.711 - 716, 2009/00

In J-PARC, a cryogenic hydrogen system, which plays a role in providing supercritical hydrogen with a pressure of 1.5 MPa and a temperature of 20 K to three moderators, has been designed. The performance test of the helium refrigeration system was conducted independently. The helium refrigeration system was cooled down to 18 K within 4.5 hours, and the refrigerator power of 6.45 kW at 15.6 K was confirmed. The performance test results proved that the helium refrigerator met the performance requirements.

Journal Articles

Commissioning of the cryogenic hydrogen system in J-PARC; First cool-down operation with helium

Tatsumoto, Hideki; Aso, Tomokazu; Kato, Takashi; Otsu, Kiichi; Hasegawa, Shoichi; Maekawa, Fujio; Futakawa, Masatoshi

Proceedings of International Cryogenic Engineering Conference 22 (ICEC-22) and International Cryogenic Materials Conference 20 (ICMC 2008), p.717 - 722, 2009/00

In J-PARC, an intense spallation neutron source (JSNS) driven by a 1-MW proton beam has been constructed. A cryogenic hydrogen system, which provides supercritical hydrogen at the temperature of around 20 K and the pressure of 1.5 MPa to the moderators and absorbs nuclear heating in the moderators, has been completed in November 2007 and the commissioning has been started. As a first step, the primary cryogenic operations were conducted by using helium, instead of hydrogen. We confirmed the system soundness at operation temperature, and established operation method of the cool-down process. The cryogenic tests have been successfully completed without problems.

Journal Articles

Commissioning of the cryogenic hydrogen system in J-PARC; Preliminary operation by helium gas

Aso, Tomokazu; Tatsumoto, Hideki; Hasegawa, Shoichi; Otsu, Kiichi; Uehara, Toshiaki; Kawakami, Yoshihiko; Sakurayama, Hisashi; Maekawa, Fujio; Futakawa, Masatoshi; Ushijima, Isamu*

Proceedings of International Cryogenic Engineering Conference 22 (ICEC-22) and International Cryogenic Materials Conference 20 (ICMC 2008), p.741 - 746, 2009/00

no abstracts in English

Journal Articles

Lifetime estimation of microbubble in mercury

Naoe, Takashi; Hasegawa, Shoichi; Bucheeri, A.; Futakawa, Masatoshi

Journal of Nuclear Science and Technology, 45(12), p.1233 - 1236, 2008/12

 Times Cited Count:4 Percentile:29.54(Nuclear Science & Technology)

Cavitation damage is a critical issue in high power mercury targets for pulsed spallation neutron sources. Cavitation is induced by pressure wave which is caused by rapid thermal expansion of mercury. Microbubble injection into the mercury target has studied to mitigate the cavitation damage. Bubble condition: distribution and size, will affect the mitigation effect. It is important to estimate bubble lifetime to determine the bubble distribution and injection region because the microbubbles are disappeared by dissolution and diffusion. In this study, since mercury is an opaque liquid, a shrinking behavior of helium microbubbles in contact with an acrylic wall were observed and their lifetime was measured. The actual lifetime of microbubble suspended in the liquid was estimated from the observed bubbles. The lifetime of microbubble in mercury is longer than that in water.

Journal Articles

Mitigation technologies for damage induced by pressure waves in high-power mercury spallation neutron sources, 2; Bubbling effect to reduce pressure wave

Futakawa, Masatoshi; Kogawa, Hiroyuki; Hasegawa, Shoichi; Naoe, Takashi; Ida, Masato; Haga, Katsuhiro; Wakui, Takashi; Tanaka, Nobuatsu*; Matsumoto, Yoichiro*; Ikeda, Yujiro

Journal of Nuclear Science and Technology, 45(10), p.1041 - 1048, 2008/10

 Times Cited Count:31 Percentile:87.02(Nuclear Science & Technology)

The life time of mercury target will be reduced by the cavitation damage induced by pressure waves. Micro-bubble injection into mercury is one of prospective technologies to mitigate the pressure waves. We have carried out damage tests using mercury loop with an impact generator to evaluate the bubbling effect on the pressure response and cavitation damage. The impulsive pressure was hardly changed but the damage was reduced remarkably by the micro-bubble injection. Numerical simulation was performed to investigate the bubbling effects. It was understandable that micro bubbles suppressed cavitation inception.

Journal Articles

Cavitation damage prediction for spallation target vessels by assessment of acoustic vibration

Futakawa, Masatoshi; Kogawa, Hiroyuki; Hasegawa, Shoichi; Ikeda, Yujiro; Riemer, B.*; Wendel, M.*; Haines, J.*; Bauer, G.*; Naoe, Takashi; Okita, Kohei*; et al.

Journal of Nuclear Materials, 377(1), p.182 - 188, 2008/06

 Times Cited Count:28 Percentile:85.19(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Numerical study on pressure wave propagation in a mercury loop

Kogawa, Hiroyuki; Hasegawa, Shoichi; Futakawa, Masatoshi; Riemer, B.*; Wendel, M.*; Haines, J.*

Journal of Nuclear Materials, 377(1), p.195 - 200, 2008/06

 Times Cited Count:3 Percentile:23.58(Materials Science, Multidisciplinary)

In beam test was carried out at the LANSCE-WNR to investigate pressure wave mitigation in mercury targets for the MW-class spallation neutron sources under international collaboration between SNS and JSNS. A mercury loop with micro bubble generator was used for the target. The loop target consists of the rectangular pipe which was made of stainless steel. The total length of the loop is about 2 m. Strain sensors were set on many points of loop to measure the strain on the pipe wall caused by the pressure wave. The maximum strain at 350 mm apart from the proton bombarded point appeared after 5.5 ms after the proton bombardment. The wave propagation velocity was slower than the stress wave and the pressure wave propagation velocities and became 65 m/s in the IBBTL. Numerical analysis result shows that the maximum strain at 350 mm apart from the proton bombarded point appeared at 5.5 ms after proton bombardment as well as the experimental due to interaction between liquid and solid.

Journal Articles

Design and application of NOBORU; NeutrOn Beam line for Observation and Research Use at J-PARC

Oikawa, Kenichi; Maekawa, Fujio; Harada, Masahide; Kai, Tetsuya; Meigo, Shinichiro; Kasugai, Yoshimi; Oi, Motoki; Sakai, Kenji; Teshigawara, Makoto; Hasegawa, Shoichi; et al.

Nuclear Instruments and Methods in Physics Research A, 589(2), p.310 - 317, 2008/05

 Times Cited Count:52 Percentile:95.04(Instruments & Instrumentation)

NOBORU, NeutrOn Beam-line for Observation and Research Use, has been constructed in the Materials and Life Science Facility (MLF) of J-PARC. NOBORU is designed to "Observe" a 1 MW Japan Spallation Neutron Source (JSNS), i.e., to study the neutronic performance of JSNS. NOBORU also will be used for "Research" activities, i.e., as a test port for R&D activities and trial users who have new ideas. In this paper, the design and application of NOBORU are described, and its expected performance is investigated by Monte Carlo simulations.

Journal Articles

Bystander killing of human lung cancer cells by heavy charged particle irradiation

Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Funayama, Tomoo; Sakurai, Hideyuki*; Sakashita, Tetsuya; Wada, Seiichi*; Kawamura, Hidemasa*; Hasegawa, Masatoshi*; Kobayashi, Yasuhiko; et al.

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 102, 2007/02

Journal Articles

Bystander effect of high linear energy transfer charged particle radiation on human glioblastoma cells

Ishiuchi, Shogo*; Hasegawa, Masatoshi*; Yoshida, Yukari*; Hamada, Nobuyuki*; Funayama, Tomoo; Wada, Seiichi*; Sakashita, Tetsuya; Kobayashi, Yasuhiko; Nakano, Takashi*

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 104, 2007/02

Journal Articles

Research of disease onset mechanism by determining the distribution of intracellular trace elements using an in-air micro-PIXE analyzer system

Nakano, Takashi*; Arakawa, Kazuo; Sakurai, Hideyuki*; Hasegawa, Masatoshi*; Yuasa, Kazuhisa*; Saito, Etsuko*; Takagi, Hitoshi*; Nagamine, Takeaki*; Kusakabe, Takahiko*; Takada, Hisashi*; et al.

International Journal of PIXE, 16(1&2), p.69 - 76, 2006/00

A new program was started out to create a new medical scientific field, which is consisting of radiation oncology and nuclear medicine, utilizing the advanced accelerator and ion beam technology. An in-air micro-PIXE analyzer system, which is among the most important technical basis of the program, was upgraded to improve accuracy of elemental mapping for samples having thickness variation in a scope of microbeam scanning. In the program, on the other hand, in order to approach important bio-medical problems on cancer, intracellular dynamics of the trace elements according to mechanism of development of diseases were studied using this system. This paper outlines this program and shows the system upgraded, and results of preliminary studied about the problems.

Journal Articles

R&D of a MW-class solid-target for spallation neutron source

Kawai, Masayoshi*; Furusaka, Michihiro*; Kikuchi, Kenji; Kurishita, Hiroaki*; Watanabe, Ryuzo*; Li, J.*; Sugimoto, Katsuhisa*; Yamamura, Tsutomu*; Hiraoka, Yutaka*; Abe, Katsunori*; et al.

Journal of Nuclear Materials, 318, p.35 - 55, 2003/05

R&D works for MW class solid target composed of tungsten to produce pulsed intense neutron source has been made in order to construct a future scattering facility. Three methods were investigated to prevent corrosion of tungsten from water; those are hipping, brazing and electric coating in molten salt bath. Hipping condition was optimized to be 1500 degree C in the previous work: here small punch test shows highest load for crack initiation of hipped materials at the boundary of W/Ta. The basic techniques for the other two methods were developed. Erosion test showed that uncovered W is susceptible of flowing water velocity. At high velocity w is easy to be eroded. For solid target design slab type and rod type targets were studied. As long as the optimized neutron performance is concerned, 1MW solid target is better than mercury target.

JAEA Reports

None

Hasegawa, Ken*; Koide, Kaoru*; Muneto, Masaru*; Nagasaki, Yasushi*; Nakano, Katsushi; Yamagishi, Akiko*; Okita, Masatoshi*

JNC TN7400 2005-020, 199 Pages, 1994/04

JNC-TN7400-2005-020.PDF:11.68MB

None

JAEA Reports

None

Tsubota, Koji*; Ochiai, Yoji*; Hanaki, Tatsumi*; Hasegawa, Ken*; Okita, Masatoshi*; Koide, Kaoru*; Nagasaki, Yasushi*

JNC TN7400 2005-019, 114 Pages, 1993/04

JNC-TN7400-2005-019.PDF:7.46MB

None

32 (Records 1-20 displayed on this page)