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Journal Articles

R&D on Accelerator Driven Nuclear Transmutation System (ADS) at J-PARC, 5; Research and developments of a superconducting linac for ADS

Kondo, Yasuhiro; Takei, Hayanori; Yee-Rendon, B.; Tamura, Jun

Purazuma, Kaku Yugo Gakkai-Shi, 98(5), p.222 - 226, 2022/05

A superconducting accelerating cavity is indispensable to realize a driver linac that meets the requirements of ADS. The low-energy section of the accelerators, which is normal conducting one, was redesigned to reflect the recent progress in the development of superconducting accelerator cavities. In addition, we are developing a prototype cavity for the spoke-type cavity that has not been developed well. This section reports on the latest research and development of ADS linacs at the Japan Atomic Energy Agency.

Journal Articles

Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation

Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.

Journal of Nuclear Science and Technology, 32 Pages, 2022/02

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.

Journal Articles

Initiatives to address the lifetime improvement of HBC stripper foil for 3GeV synchrotron of J-PARC

Yoshimoto, Masahiro; Nakanoya, Takamitsu; Yamazaki, Yoshio; Saha, P. K.; Kinsho, Michikazu; Yamamoto, Shunya*; Okazaki, Hiroyuki*; Taguchi, Tomitsugu*; Yamada, Naoto*; Yamagata, Ryohei*

Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.850 - 854, 2021/10

no abstracts in English

JAEA Reports

Assessment report on research and development activities in FY 2018; Activity "Research and development on J-PARC" (Interim report)

J-PARC Center

JAEA-Evaluation 2019-003, 52 Pages, 2019/06

JAEA-Evaluation-2019-003.pdf:6.61MB

Evaluation Committee of Research Activities for J-PARC for interim assessment of Japan Proton Accelerator Research Complex evaluated the management and research activities of J-PARC center on the explanatory documents and oral presentations during the period from April 2015 to December 2018. This report summarizes the results of the assessment by the Committee with the Committee report attached.

Journal Articles

Fundamental aspects of neutron moderators and neutron beam optics for designing high intensity laser-driven neutron source

Ikeda, Yujiro; Shimizu, Hirohiko*

Reza Kenkyu, 46(11), p.641 - 646, 2018/11

In viewing significant progresses in technical achievement toward a high-intensity neutron source driven by a high-power laser came up with the high power laser development, we have reviewed the currently most advanced moderator system and neutron optics, which are the key elements for the neutron beam applications. Regarding the moderators, concepts adopted in J-PARC pulsed neutron source, which is one of most advanced system, were described to give a baseline design. Also a new direction of moderator concept is shown, which could be a high brightness candidate for the high-intensity laser driven system. On the neutron optics, the most fundamental consideration is primarily reviewed along with recent progress in new devises for enrichment of neutron-beam characteristics.

Journal Articles

Pulse-by-pulse switching of operational parameters in J-PARC 3-GeV RCS

Hotchi, Hideaki; Watanabe, Yasuhiro; Harada, Hiroyuki; Okabe, Kota; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Yoshimoto, Masahiro

Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.1041 - 1044, 2018/06

Journal Articles

New injection scheme of J-PARC rapid cycling synchrotron

Yamamoto, Kazami; Kamiya, Junichiro; Saha, P. K.; Takayanagi, Tomohiro; Yoshimoto, Masahiro; Hotchi, Hideaki; Harada, Hiroyuki; Takeda, Osamu*; Miki, Nobuharu*

Proceedings of 8th International Particle Accelerator Conference (IPAC '17) (Internet), p.579 - 581, 2017/05

The 3-GeV Rapid Cycling Synchrotron of Japan Proton Accelerator Research Complex aims to deliver 1-MW proton beam to the neutron target and Main Ring synchrotron. Present beam power of the Rapid Cycling Synchrotron is up to 500-kW and the higher radiation doses were concentrated in the injection area. These activations were caused by the interaction between the foil and the beam. To reduce the worker dose near the injection point, we have studied a new design of the injection scheme to secure enough space for radiation shielding and bellows. In the new system, two of four injection pulse bump magnets are replaced and we are able to ensure the additional space around the injection foil chamber. So far, new injection system seems not impossible. However, preliminary study result indicated that temperature of the duct and shielding metals would be slightly higher. The eddy current due to the shift bump magnet field generates heat. Thus we have to study details of above effect.

Journal Articles

Longitudinal particle tracking code for a high intensity proton synchrotron

Yamamoto, Masanobu

Proceedings of 57th ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2016) (Internet), p.110 - 114, 2016/08

We have been developing a longitudinal particle tracking code for a high intensity proton synchrotron, especially for the J-PARC Synchrotron. Although some longitudinal particle tracking codes exist, our code can track the particles with a wake voltage and a space charge effect, and also can calculate a beam emittance and a momentum filling factor under a multi-harmonics to evaluate the margin of a rf bucket. Furthermore, we originally have developed the calculation method of a synchronous particle, which realizes the simulation in the case that the revolution frequency of the synchronous particle is not proportional to an acceleration frequency pattern. This is useful to check an adiabaticity. We have achieved 1 MW-eq. beam acceleration at J-PARC RCS by using the code because we can calculate the optimum acceleration conditions for the high intensity beam. We will describe the basic design of the code and the simulation results for the J-PARC RCS and MR.

Journal Articles

Radiation safety design for the J-PARC project

Nakashima, Hiroshi; Nakane, Yoshihiro; Masukawa, Fumihiro; Matsuda, Norihiro; Oguri, Tomomi*; Nakano, Hideo*; Sasamoto, Nobuo*; Shibata, Tokushi*; Suzuki, Takenori*; Miura, Taichi*; et al.

Radiation Protection Dosimetry, 115(1-4), p.564 - 568, 2005/12

 Times Cited Count:7 Percentile:47.08(Environmental Sciences)

The High Intensity Proton Accelerator Project, named as J-PARC, is in progress, aiming at studies on the latest basic science and the advancing nuclear technology. In the project, the high-energy proton accelerator complex of the world highest intensity is under construction. In order to establish a reasonable shielding design, both simplified and detailed design methods were used in the shielding design of J-PARC. This paper reviews the present status of the radiation safety design study for J-PARC.

JAEA Reports

Standard of radiation monitor based on LAN and PLC technology for J-PARC

Miyamoto, Yukihiro; Sakamaki, Tsuyoshi*; Maekawa, Osamu*; Nakashima, Hiroshi

JAERI-Tech 2004-054, 72 Pages, 2004/08

JAERI-Tech-2004-054.pdf:7.3MB

A standard is provided for the radiation monitor based on LAN (Local Area Network) and PLC (Programmable Logic Controller) technology at the introduction to the Japan Proton Accelerator Research Complex (J-PARC). The monitor consists of radiation measurement equipments and the central monitoring panel. The formers are installed in the radiation field, and the latter is installed in the control room and composed of PLC, which are connected with LAN. Extension of the existing standard and the conformity to the international standard were thought as important in providing the standard. The standard is expected to improve the compatibility, maintenancability and productivity of the components.

Journal Articles

Generation of X-rays and energetic ions from superintense laser irradiation of micron-sized Ar clusters

Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Kishimoto, Yasuaki; Yamakawa, Koichi; Faenov, A. Y.*; Magunov, A. I.*; Pikuz, T. A.*; et al.

Laser and Particle Beams, 22(3), p.215 - 220, 2004/07

 Times Cited Count:41 Percentile:80.38(Physics, Applied)

High resolution K-shell spectra of a plasma created by superintense laser irradiation of micron-sized Ar clusters have been measured with an intensity above 10$$^{19}$$ W/cm$$^2$$ and a pulse duration of 30 fs. The total photon flux of 2$$times$$10$$^8$$ photons/pulse was achieved for He$$_{alpha1}$$ resonant line of Ar ($$lambda$$=3.9491 AA , 3.14 keV). In parallel with X-ray measurements, energy distributions of emitted ions have been measured. The multiply-charged ions with kinetic energies up to 800 keV were observed. It is found that hot electrons produced by high contrast laser pulses allow the isochoric heating of clusters and shift the ion balance towards the higher charge states, which enhances both the X-ray line yield of the He-like argon ion and the ion kinetic energy.

Journal Articles

Roundness and straightness measurement of ceramic beam ducts for the 3GeV-synchrotron of Japan-Proton Accelerator Research Complex

Nishizawa, Daiji*; Kinsho, Michikazu; Kanazawa, Kenichiro; Ogiwara, Norio; Saito, Yoshio*; Kubo, Tomio*; Sato, Yoshihiro*

Shinku, 47(4), p.339 - 343, 2004/05

no abstracts in English

JAEA Reports

Design report on the 3-GeV proton beam transport facility (3NBT) of High Intensity Proton Accelerator facility (J-PARC)

Sakamoto, Shinichi; Meigo, Shinichiro; Konno, Chikara; Kai, Tetsuya; Kasugai, Yoshimi; Harada, Masahide; Fujimori, Hiroshi*; Kaneko, Naokatsu*; Muto, Suguru*; Ono, Takehiro*; et al.

JAERI-Tech 2004-020, 332 Pages, 2004/03

JAERI-Tech-2004-020.pdf:17.93MB

One of the experimental facilities in Japan Proton Accelerator Research Complex (J-PARC) is the Materials and Life Science Experimental Facility (MLF), where high-intensity neutron beams and muon beams are used as powerful probes for materials science, life science and related engineering. The neutrons and muons are generated with high-intensity proton beam from 3-GeV rapid cycling synchrotron (RCS). The high-intensity proton beam has to be effectively transported, and a neutron production target and a muon production target have to be also properly irradiated. The principal design of the 3-GeV proton beam transport facility (3NBT) is systematized.

JAEA Reports

High Intensity Proton Accelerator Project (J-PARC) technical design report materials & life science experimental facility

Materials & Life Science Experimental Facility Construction Team

JAERI-Tech 2004-001, 1171 Pages, 2004/03

JAERI-Tech-2004-001-Part1.pdf:80.84MB
JAERI-Tech-2004-001-Part2.pdf:43.14MB

This report summarizes conceptual design study up to March, 2003, relevant to the Materials & Life Science Experimental Facility construction which is one of the major user facilities to be constructed under the J-PARC project of High Intensity Proton Accelerator. The first chapter corresponds to the design manual, and the followings stand for the technical parts giving the design principle and detailed results for the studies. As the project is evolving day by day, some of studies have been advanced since the moment of this summary in one hand, and some of parts are close to final stage of design. Including those, more comprehensive and updated version of the technical designs are to be reported accordingly.

Journal Articles

Roundness and straightness measurement of ceramic beam ducts for the 3GeV-synchrotron of Japan-proton accelerator research complex

Nishizawa, Daiji*; Kinsho, Michikazu; Kanazawa, Kenichiro; Ogiwara, Norio; Saito, Yoshio*; Kubo, Tomio*; Sato, Yoshihiro*

Shinku, 47(4), p.339 - 343, 2004/02

Large aperture cylindrical beam ducts consisting of alumina ceramics will be used for the first time in the 3GeV-synchrotron of High Intensity Proton Accelerator Facility. It is necessary to evaluate roundness and straightness of ceramic ducts because we have to compensate contact area of the connected beam duct large as well as we have to compensate large enough beam aperture. We developed an apparatus of measuring roundness and straightness, and we completed data analysis method as well as measuring method. Then we are measuring and evaluating roundness and straightness of ceramic beam ducts. Now, we have newly made an ellipse ceramic duct for the 3GeV-synchrotron BM. This duct has ellipse cross-sections to satisfy with larger aperture that the beam dynamics requires. In this conference, we are going to present taken data and findings regarding form accuracy including roundness and straightness of the ellipse ceramic duct.

Journal Articles

X-ray radiation of clusters irradiated by ultrafast, high-intensity laser pulses

Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Kishimoto, Yasuaki; Yamakawa, Koichi; Faenov, A. Y.*; Magunov, A. I.*; Pikuz, T. A.*; et al.

Laser-Generated & Other Lab. X-Ray & EUV Sources (Proceedings of SPIE Vol.5196), p.234 - 243, 2004/00

High resolution X-ray emission spectra of plasma created by laser irradiation of rare-gas (Ar, Kr, Xe) clusters have been measured at laser intensities over 10$$^{19}$$ W/cm$$^2$$ and 30-fs pulse duration. To make these measurements possible, in addition to the effort to decrease a prepulse intensity using Pockels cell switches, micron-size clusters were produced using a specially designed conical nozzle. The Boltzmann equation and a detailed collisional radiative model are solved simultaneously as a function of time to model the time integrated X-ray spectra of the transient plasma. The results are quantitatively in good agreement with the experimentally observed X-ray emission spectra of Ar clusters.

Journal Articles

J-PARC construction and its linac commissioning

Yamazaki, Yoshishige

Proceedings of 9th European Particle Accelerator Conference (EPAC 2004), p.1351 - 1353, 2004/00

The J-PARC (Japan Proton Accelerator Research Complex) is under construction in JAERI Tokai site. The beam commissioning will start there by the end of 2006. Prior to this, the front end of the linac was beam-commissioned in 2003 at KEK. The negative hydrogen beam with a peak current of 30 mA was accelerated up to 20 MeV by the first tank of the three DTL's following the 3-MeV RFQ linac. The 324-MHz DTL contains the electro quadrupole magnets with water-cooling channels specially fabricated by means of electroforming and wire-cutting technologies. The construction status of the J-PARC accelerator is also presented.

Journal Articles

Time-dependent Boltzmann kinetic model of X-rays produced by ultrashort-pulse laser irradiation of argon clusters

Abdallah, J. Jr.*; Csanak, G.*; Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Yamakawa, Koichi; Faenov, A. Y.*; Magunov, A. I.*; et al.

Physical Review A, 68(6), p.063201_1 - 063201_8, 2003/12

 Times Cited Count:52 Percentile:87.91(Optics)

The Boltzmann Equation and a detailed collisional radiative model are solved simultaneously as a function of time to model the time integrated X-ray spectra of the transient plasma produced by a high intensity ultrafast laser source. The results are in agreement with highly resolved F-like to He-like K-shell emission spectra recorded recently during ultrashort laser experiments with argon cluster targets in Japan.

Journal Articles

X-ray study of microdroplet plasma formation under the action of superintense laser radiation

Fukuda, Yuji; Yamakawa, Koichi; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Abdallah, J. Jr.*; Csanak, G.*; Faenov, A. Y.*; Magunov, A. I.*; et al.

JETP Letters, 78(3), p.115 - 118, 2003/08

 Times Cited Count:28 Percentile:77.32(Physics, Multidisciplinary)

We have measured the X-ray emission spectra of a plasma generated by laser radiation with an intensity above 10$$^{19}$$ W/cm$$^2$$ and a pulse duration of 30 fs acting uon an argon jet target with a large aboundance of micron-sized clusters. The time variation of the X-ray yeild from various multiplicities, calculated within the framework of a nonstationary kinetic model, shows a good qualitative agreement with the experimental time-integrated spectrum.

Journal Articles

Target station design of 1 MW spallation neutron source at the high intensity proton accelerator facilities J-PARC

Takada, Hiroshi; Maekawa, Fujio; Honmura, Shiro*; Yoshida, Katsuhiko*; Teraoku, Takuji*; Meigo, Shinichiro; Sakai, Akio*; Kasugai, Yoshimi; Kanechika, Shuji*; Otake, Hidenori*; et al.

Proceedings of ICANS-XVI, Volume 3, p.1115 - 1125, 2003/07

no abstracts in English

41 (Records 1-20 displayed on this page)