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Journal Articles

Measurement of the neutron capture cross section of $$^{185}$$Re in the keV energy region

Katabuchi, Tatsuya*; Sato, Yaoki*; Takebe, Karin*; Igashira, Masayuki*; Umezawa, Seigo*; Fujioka, Ryo*; Saito, Tatsuhiro*; Iwamoto, Nobuyuki

Journal of Nuclear Science and Technology, 6 Pages, 2024/00

Journal Articles

Development of long pulse arc driven ion source for iBNCT

Shibata, Takanori*; Sugimura, Takashi*; Ikegami, Kiyoshi*; Takagi, Akira*; Sato, Masaharu*; Naito, Fujio*; Okoshi, Kiyonori; Hasegawa, Kazuo

JPS Conference Proceedings (Internet), 33, p.011009_1 - 011009_6, 2021/03

Upgrade of beam current in the Linac of Ibaraki Boron Neutron Capture Therapy (iBNCT) is one of the most important requirements to realize clinical trial. By 2018, the measurement of the produced neutrons characteristics and the neutron irradiation experiment for living cells have been done by producing 8-MeV proton beam current at the beryllium target with average current up to 2 mA. In order to satisfy the original clinical trial conditions, 5 mA average beam current is required at the target. For this goal, peak beam current extracted from the ion source should be increased to 60 mA from the present 30 mA with duty factor up to more than 10% (pulse width up to 1 ms and repetition rate up to more than 100 Hz). Stability of the peak current in the macro pulse is also important for the clinical application.

Journal Articles

Status of development on LaB$$_6$$ filament arc-driven multi-cusp ion source for iBNCT

Shibata, Takanori*; Takagi, Akira*; Ikegami, Kiyoshi*; Sugimura, Takashi*; Nammo, Kesao*; Naito, Fujio*; Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Honda, Yosuke*; Sato, Masaharu*; et al.

Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.385 - 387, 2018/10

Journal Articles

Non-aqueous selective synthesis of orthosilicic acid and its oligomers

Igarashi, Masayasu*; Matsumoto, Tomohiro*; Yagihashi, Fujio*; Yamashita, Hiroshi*; Ohara, Takashi; Hanashima, Takayasu*; Nakao, Akiko*; Moyoshi, Taketo*; Sato, Kazuhiko*; Shimada, Shigeru*

Nature Communications (Internet), 8, p.140_1 - 140_8, 2017/07

 Times Cited Count:25 Percentile:64.44(Multidisciplinary Sciences)

Journal Articles

Beam commissioning of the linac for iBNCT

Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11

The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.

Journal Articles

Impact of PHITS spallation models on the neutronics design of an accelerator-driven system

Iwamoto, Hiroki; Nishihara, Kenji; Iwamoto, Yosuke; Hashimoto, Shintaro; Matsuda, Norihiro; Sato, Tatsuhiko; Harada, Masahide; Maekawa, Fujio

Journal of Nuclear Science and Technology, 53(10), p.1585 - 1594, 2016/10

 Times Cited Count:16 Percentile:85.95(Nuclear Science & Technology)

Journal Articles

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

no abstracts in English

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:16.14(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

High-power test and thermal characteristics of a new radio-frequency quadrupole cavity for the Japan Proton Accelerator Research Complex linac

Kondo, Yasuhiro; Morishita, Takatoshi; Hasegawa, Kazuo; Chishiro, Etsuji; Hirano, Koichiro; Hori, Toshihiko; Oguri, Hidetomo; Sato, Fumiaki; Shinozaki, Shinichi; Sugimura, Takashi*; et al.

Physical Review Special Topics; Accelerators and Beams, 16(4), p.040102_1 - 040102_8, 2013/04

 Times Cited Count:15 Percentile:68.41(Physics, Nuclear)

We performed a high-power test of a new radio-frequency quadrupole (RFQ II) for the J-PARC linac. RFQ II was developed as a spare RFQ because the operating J-PARC RFQ has suffered from a sparking problem. First, the conditioning of RFQ II was carried out; after 50 h of conditioning, RFQ II became very stable with a nominal power and duty of 330 kW and 3%, respectively. Next the thermal properties were measured because the resonant frequency of RFQ II is tuned by changing the temperature of the cooling water. The frequency response was measured and compared to finite-element method simulation results, confirming that the simple two-dimensional model reproduces the experimental data well. The differences in the field distribution with changes in the rf loading and the cooling-water temperature were also measured, and no serious field distortion was observed. Therefore, we conclude that RFQ II can perform well as a high-power rf cavity.

Journal Articles

Visibility estimation for neutron resonance absorption radiography using a pulsed neutron source

Kai, Tetsuya; Maekawa, Fujio; Oshita, Hidetoshi*; Sato, Hirotaka; Shinohara, Takenao; Oi, Motoki; Harada, Masahide; Uno, Shoji*; Otomo, Toshiya*; Kamiyama, Takashi*; et al.

Physics Procedia, 43, p.111 - 120, 2013/00

 Times Cited Count:17 Percentile:98.1

A neutron imaging instrument is in construction at the pulsed neutron source of J-PARC. Some demonstration experiments in NOBORU/J-PARC have carried. To explore widespread applications of the newly built instruments it is indispensable to indicate the range of coverage of this technique. In the presentation, the authors describe the results of some of demonstration measurements, and then compare all elements with the values obtained by multiplying peak cross section and peak widths of neutron resonances in evaluated nuclear data libraries. This value is expected to be a good measure to exhibit visibility of each element in this technique.

JAEA Reports

Maintenance of used components in spallation neutron source; Moderator $$cdot$$ reflector and proton beam window

Teshigawara, Makoto; Kinoshita, Hidetaka; Wakui, Takashi; Meigo, Shinichiro; Seki, Masakazu; Harada, Masahide; Ito, Manabu; Suzuki, Toru; Ikezaki, Kiyomi; Maekawa, Fujio; et al.

JAEA-Technology 2012-024, 303 Pages, 2012/07

JAEA-Technology-2012-024.pdf:46.04MB

3 GeV Protons with 1 MW beam power are irradiated to mercury target of spallation neutron source in Materials and Life science Facility (MLF), which is one of facilities of J-PARC. Irradiated components, such as target container, moderator, reflector and proton beam window, are needed to replace periodically due to irradiation damage of high energy protons and neutrons. These used components are replaced remotely because of highly activated. Maintenance scenario was settled so as to handle these components. Required remote handling machines were designed and installed in hot cell and other room of the MLF. We performed remote handling tests by using actual components to confirm the design. We report results, such as replacement procedure, trouble and its solution, etc., for moderator, reflector and proton beam window in order to provide the handling of actual used components.

Journal Articles

Present status of RF source in J-PARC linac; Recovery from earthquake disaster and energy upgrade

Kawamura, Masato*; Chishiro, Etsuji; Shinozaki, Shinichi; Fang, Z.*; Fukui, Yuji*; Naito, Fujio*; Yamazaki, Masayoshi*; Tsubota, Naoaki; Futatsukawa, Kenta; Sato, Fumiaki; et al.

Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), 3 Pages, 2011/08

We will report about status of linac 400 MeV upgrade program and northeast Japan earthquake restoration. On March 11, the linac suffered serious damage as consequence of the earthquake, and was shuttled down for long term. Linac RF group restores the facilities and is accomplishing 400 MeV upgrade at the same time.

JAEA Reports

Preliminary design of beamline components for JT-60SA NBI heating system

Mogaki, Kazuhiko; Kazawa, Minoru; Komata, Masao; Kawai, Mikito; Ikeda, Yoshitaka; Otsuki, Shinichi*; Sato, Fujio*

JAEA-Technology 2007-025, 37 Pages, 2007/03

JAEA-Technology-2007-025.pdf:6.84MB

The modification of the beamline components for JT-60SA NBI heating system has been preliminarily studied by means of three-dimensional Computer Aided Design (CAD) technique, such as the connection between positive ion-based NBI (P-NBI) port and the cryostat of JT-60SA vacuum vessel, an additional magnetic shielding plate, the down-shift of the negative ion-based NBI (N-NBI), and disassembly of the present NBI system. The length of drift duct for JT-60SA is to be shorted because the cryostat is to be inserted between the JT-60SA vacuum vessel and the P-NBI beamline. It is found that the removal of the fast shutter and a newly designed connection flange made of FRP is a solution to keep the same function in the shorten drift duct. The position interference with the 3D CAD indicates that the available space between the neutralizer cell and the ion tank is 30 mm, which is enough space to install a thick mild steel to avoid the magnetic saturation. On the N-NBI, the down-shift of 0.6 m is realized by shorting the basement of ion tank, reversing the shaft of the movable calorimeter and exchanging the support structure of the neutralizer cell. Moreover, the minimum dissection components and the disassembly procedure have been proposed to effectively disassemble the present NBI system.

Journal Articles

Effect of proton beam profile on stress in JSNS target vessel

Kogawa, Hiroyuki; Ishikura, Shuichi*; Sato, Hiroshi; Harada, Masahide; Takatama, Shunichi*; Futakawa, Masatoshi; Haga, Katsuhiro; Hino, Ryutaro; Meigo, Shinichiro; Maekawa, Fujio; et al.

Journal of Nuclear Materials, 343(1-3), p.178 - 183, 2005/08

 Times Cited Count:8 Percentile:49.23(Materials Science, Multidisciplinary)

A cross-flow type (CFT) mercury target with flow guide blades, which has been developed for JSNS, can suppress the generation of stagnant flow region especially near the beam window where the peak heat density is generated due to spallation reaction. Then, a flat type beam window has been applied to the CFT target from the viewpoint of suppressing dynamic stress caused by a pressure wave, which has been estimated with a mercury model of the linear equation of state. The recent experimental results obtained by using a proton beam incidents to mercury led that a cutoff pressure model in the equation of state of mercury caused a suitable dynamic stress with experimental results. Dynamic stress analyses were carried out with the cutoff pressure model, in which the negative pressure less than 0.15 MPa was not generated. The generated dynamic stress in the flat beam window became much larger than that in a semi-cylindrical type window. However, the generated stress in the semi-cylindrical type beam window was over the allowable stress of SS316L under the peak heat density of 668 W/cc. In order to decrease the dynamic stress in the semi-cylindrical beam window, the incident proton beam was defocused to decrease the peak heat density down to 218 W/cm$$^{3}$$. As a result, the dynamic stress could be suppressed less than the allowable stress. On the other hand, due to defocus of the proton beam, high heat density was generated on the end of the flow guide blades, which caused high thermal stress exceeding the allowable stress. To decrease the thermal stress, several shapes of the blade ends were studied analytically, which were selected so as not to affect the mercury flow distribution. A simple thin-end blade showed low thermal stress below the allowable stress.

Journal Articles

Analysis of neutronic experiment on a simulated mercury spallation neutron target assembly bombarded by Giga-electron-Volt protons

Maekawa, Fujio; Meigo, Shinichiro; Kasugai, Yoshimi; Takada, Hiroshi; Ino, Takashi*; Sato, Setsuo*; Jerde, E.*; Glasgow, D.*; Niita, Koji*; Nakashima, Hiroshi; et al.

Nuclear Science and Engineering, 150(1), p.99 - 108, 2005/05

 Times Cited Count:6 Percentile:40.53(Nuclear Science & Technology)

A neutronic benchmark experiment on a simulated spallation neutron target assembly with 1.94, 12 and 24 GeV proton beams conducted by using the AGS accelerator at BNL/US was analyzed to investigate validity of neutronics calculations on proton accelerator driven spallation neutron sources. Monte Carlo particle transport calculation codes NMTC/JAM, MCNPX and MCNP-4A with associated cross section data in JENDL and LA-150 were used for the analysis. As a result, although the overall energy range was encompassed from GeV to meV, i.e., more than 12 orders of magnitude, calculated fast and thermal neutron fluxes agreed approximately within $$pm$$ 40 % with the experiments. Accordingly, it was concluded that neutronics calculations with these codes and cross section data were adequate for estimating nuclear properties in spallation neutron sources.

Journal Articles

Development of a magnetic focusing device for pulsed neutrons

Suzuki, Junichi; Oku, Takayuki; Adachi, Tomohiro*; Shimizu, Hirohiko; Kiyanagi, Yoshiaki*; Kamiyama, Takashi*; Hiraga, Fujio*; Iwasa, Hirokatsu*; Sato, Koichi*; Furusaka, Michihiro*

Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.120 - 124, 2004/08

 Times Cited Count:11 Percentile:58.63(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Beam commissioning of the J-PARC linac DTL1 at KEK

Kondo, Yasuhiro; Akikawa, Hisashi; Anami, Shozo*; Asano, Hiroyuki*; Fukui, Yuji*; Igarashi, Zenei*; Ikegami, Kiyoshi*; Ikegami, Masanori*; Ito, Takashi; Kawamura, Masato*; et al.

Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.156 - 158, 2004/08

A commissioning of the J-PARC linac DTL1 is now under way at KEK. A 30mA H$$^{-}$$ beam was accelerated to 19.7-MeV, and 100% transmission was obtained with a 20-msec-pulse-width and 12.5-Hz-repetition beam. In this paper, present status of the DTL1 commissioning and preliminary results of the commissioning, such as emittance measurements, are presented.

JAEA Reports

Technical report on the structural integrity and the lifetime evaluation for the mercury target vessel

Ishikura, Shuichi*; Futakawa, Masatoshi; Kogawa, Hiroyuki; Meigo, Shinichiro; Maekawa, Fujio; Harada, Masahide; Sato, Hiroshi; Haga, Katsuhiro; Ikeda, Yujiro

JAERI-Tech 2004-028, 123 Pages, 2004/03

JAERI-Tech-2004-028.pdf:9.55MB

This report describes the structural design concept applied to the mercury target vessel used for the spallation neutron source installed in the material and life science experiment facility of J-PARC (Japan Proton Accelerator Complex), and the results evaluated on the basis of the concept. The features of the design concept are as follows: (1) The target vessel design is followed to "Law concerning Prevention from Radiation Hazards due to Radio-Isotopes". That is because (i) there is not the possibility in the target of the RIA (Reactivity Initiated Accident) generally considered in the nuclear power reactors, and (ii) the target vessel is not a permanent structure. (2) Therefore, the Class 1 Vessel of the JIS B-8270 [design code for pressure vessel] that is equivalent to a standard for nuclear power structural design is applicable as a design code for the target to sufficiently keep the safety of target system. The stresses for the design were evaluated using the linear elastic analysis based on the infinitesimal strain theory in order to confirm the safe and rational design.

Journal Articles

Current status of the AGS spallation target experiment

Nakashima, Hiroshi; Takada, Hiroshi; Kasugai, Yoshimi; Meigo, Shinichiro; Maekawa, Fujio; Kai, Tetsuya; Konno, Chikara; Ikeda, Yujiro; Oyama, Yukio; Watanabe, Noboru; et al.

Proceedings of 6th Meeting of the Task Force on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6), (OECD/NEA No.3828), p.27 - 36, 2004/00

no abstracts in English

JAEA Reports

A Study of the Criticality Safety Design for the Metal Fuel Recycle System

Nakabayashi, Hiroki; Fujioka, Tsunaaki; Sato, Koji; Aoki, Kazuo*

JNC TN9400 2003-082, 67 Pages, 2003/09

JNC-TN9400-2003-082.pdf:3.02MB

This report accounts for a study about the criticality safety design for the large-scale electrorefiner, which is designed in the activities of "The Design Study of Metal Fuel Recycle System(2002)", under the collaboration with Central Research Institute od Electric Power Industry.

64 (Records 1-20 displayed on this page)