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TaEndo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto
Nuclear Science and Engineering, 198(4), p.786 - 803, 2024/04
Times Cited Count：1 Percentile：63.33(Nuclear Science & Technology)Saito, Junichi; Monbernier, M.*
Surfaces and Interfaces (Internet), 41, p.103248_1 - 103248_8, 2023/10
Times Cited Count：0 Percentile：0.01(Chemistry, Physical)Ho, H. Q.; Honda, Yuki*; Hamamoto, Shimpei; Ishii, Toshiaki; Fujimoto, Nozomu*; Ishitsuka, Etsuo
Applied Radiation and Isotopes, 140, p.209 - 214, 2018/10
Times Cited Count：3 Percentile：29.51(Chemistry, Inorganic & Nuclear)Yamamoto, Masanobu; Ezura, Eiji*; Hara, Keigo*; Hasegawa, Katsushi*; Nomura, Masahiro; Omori, Chihiro*; Schnase, A.*; Shimada, Taihei; Takagi, Akira*; Takata, Koji*; et al.
JPS Conference Proceedings (Internet), 8, p.012015_1 - 012015_6, 2015/09
The J-PARC MR provides a coasting proton beam for nuclear physics experiments by slow extraction. The longitudinal emittance should be enlarged until the MR flat top to mitigate the microwave instability. We have investigated a Phase Modulation (PM) method by using a High Frequency Cavity (HFC) to increase the emittance. We have performed extensive simulation studies to find the appropriate parameters of the PM through the particle tracking simulation. We found that the effective HFC frequency has linear dependence with the PM frequency, where the emittance is smoothly enlarged. Furthermore, we found that the required HFC voltage is inverse proportional to the square root of the duration time of the PM. These PM properties will be used for the design of the HFC. We describe the particle tracking simulation results of controlled emittance blow-up by the PM.
Kubo, Hirotaka; Takenaga, Hidenobu; Sawada, Keiji*; Nakano, Tomohide; Kobayashi, Shinji*; Higashijima, Satoru; Asakura, Nobuyuki; Shimizu, Katsuhiro
Journal of Nuclear Materials, 337-339, p.161 - 165, 2005/03
Times Cited Count：16 Percentile：71.71(Materials Science, Multidisciplinary)no abstracts in English
Okawa, Tomohiro*; Ikegami, Masanori*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.3091 - 3093, 2005/00
L3BT is beam transportation line from the linac to the 3-GeV RCS which is the part of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. In this paper, especially results of the beam simulation of the injection section of the L3BT are presented. The injection section is necessary for a successful adjustment to the transported beam to the required parameters for ring injection. The matching of beams envelopes and dispersion function for space charge dominative beams are also discussed.
Shibamoto, Yasuteru; Yonomoto, Taisuke; Nakamura, Hideo; Nishikizawa, Tomotoshi
Proceedings of 4th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-4), p.210 - 214, 2004/11
no abstracts in English
Hajima, Ryoichi
Nuclear Instruments and Methods in Physics Research A, 528(1-2), p.335 - 339, 2004/08
Times Cited Count：20 Percentile：76.36(Instruments & Instrumentation)Dilution of electron beam emittance through a return arc is one of critical problems in the design of an energy-recovery linac for high-power FEL and a synchrotron light source. We present that the emittance dilution can be compensated by establishing the matching between the phase ellipse orientation and the CSR kick direction, and the effect of coherent synchrotron radiation on the beam emittance dilution can be estimated from simple calculation of transfer matrices.
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.
Pu and 
-decay energy of NpNishio, Katsuhisa; Ikezoe, Hiroshi; Mitsuoka, Shinichi; Sato, Kenichiro; Lin, C. J.
Physical Review C, 68(6), p.064305_1 - 064305_6, 2003/12
Times Cited Count：28 Percentile：80.93(Physics, Nuclear)We observed two -decay chains starting from Pu in the reaction of 
S+
Pt, and the half-life was measured to be 1.1
s for the first time. This contradicts the literature value of 4 ms as an upper limit, although the -decay energy agrees with each other. The present half-life follows the Geiger-Nuttall curve for even-even Pu isotopes, showing the dominant -decay branch. In this reaction, six decays of Np were firstly observed. The average -particle energy was 7097
61 keV. The evaporation residue cross sections of Pu, Np and 
U are reproduced by a statistical model calculation.
Hajima, Ryoichi
Japanese Journal of Applied Physics, Part 2, 42(8A), p.L974 - L976, 2003/08
Times Cited Count：21 Percentile：61.56(Physics, Applied)A first-order transform matrix is proposed to calculate electron beam emittance dilution arising from coherent synchrotron radiation (CSR) in a next-generation light source based on an energy-recovery linac. The matrix approach enable us to scan a lot of parameters for the design of achromatic cells of minimum emittance dilution. The emitatce dilution can be minimized when the CSR wake dispersion matches to the betatron function envelope at the achromatic cell exit.
Hajima, Ryoichi
Proceedings of 28th Linear Accelerator Meeting in Japan, p.288 - 290, 2003/08
no abstracts in English
Watanabe, Kazuhiro; Iga, Takashi*; Morishita, Takatoshi; Kashiwagi, Mieko; Inoue, Takashi; Hanada, Masaya; Taniguchi, Masaki; Imai, Tsuyoshi
Proceedings of 28th Linear Accelerator Meeting in Japan, p.186 - 188, 2003/08
no abstracts in English
Endo, Akira; Sato, Kaoru; Noguchi, Hiroshi; Tanaka, Susumu; Iida, Takao*; Furuichi, Shinya*; Kanda, Yukio*; Oki, Yuichi*
Journal of Radioanalytical and Nuclear Chemistry, 256(2), p.231 - 237, 2003/05
Times Cited Count：7 Percentile：45.73(Chemistry, Analytical)Size distributions of 
Cl, 
Cl, 
Br and 
Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45MeV and 65MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive particles in high energy radiation fields. Effects of the size distribution of the radioactive aerosols on the size of added DOP aerosols, the energy of irradiation neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols.
Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi
Proceedings from the International Conference on Radioactivity in the Environment (CD-ROM), 4 Pages, 2002/09
The present study aims to expanding the capability of WSPEEDI, so that it can be applied to atmospheric releases of radionuclides in the world for terrorist attack as well as nuclear accident. A terrorist attack would be possible in any time, any place and any scale. Altough WSPEEDI has already had a function to acquire global meteorological forecasts to generate a geographical map at arbitrary region in the world, it had no capability for simultaneous multi-scale predictions. Thus, the combination of models, non-hydrostatic meteorological model MM5 and atmospheric dispersion model GEARN, is introduced to WSPEEDI. MM5 can forecast local and regional meteorological condition simultaneously by domain nesting calculations. By the input of meteorological condition generated by MM5, GEARN can forecast multi-scale environmental contaminations considering detailed boundary layer and precipitation processes. Using this improved WSPEEDI, we made test calculations assuming a nuclear accident or terrorist attack in Asia.
Watanabe, Kazuhiro
Purazuma, Kaku Yugo Gakkai-Shi, 78(6), p.535 - 540, 2002/06
Development of ion sources for International Fusion Materials Irradiation Facility (IFMIF) which is an accelerator based high intensity neutron source to test and develop materials for fusion machines has being conducted. Required specifications of the ion source are 100 keV, 155mA of D+ with CW operation. This report presents about the over view of the IFMIF and present status of the ion source development.
Atarashi-Andoh, Mariko; Amano, Hikaru; Takahashi, Tomoyuki*
Fusion Science and Technology, 41(3), p.470 - 473, 2002/05
During normal operation or an accident of nuclear facilities, tritium will be released mostly as forms of HT and HTO to the environment. ETDOSE is a simple computer code to calculate atmospheric distribution patterns of tritium for an acute and a chronic release of HT and HTO. This code calculates tritium concentrations in air, soil, plant free water and OBT, and estimates dose impact by inhalation of air and ingestion of food. ETDOSE has GUI interface, so anyone can use it very easily. Participation in IAEA's model validation program BIOMASS has been done using this code for BIOMASS Scenario 1. In the scenario, tritium is assumed to be released continuously to the atmosphere as forms of HT or HTO. We shows the outline of ETDOSE and results of the application.
Endo, Akira; Noguchi, Hiroshi; Tanaka, Susumu; Kanda, Yukio*; Oki, Yuichi*; Iida, Takao*; Sato, Kaoru; Tsuda, Shuichi
Applied Radiation and Isotopes, 56(4), p.615 - 620, 2002/04
Times Cited Count：3 Percentile：23.20(Chemistry, Inorganic & Nuclear)Formation mechanism and size distribution of radioactive aerosol particles generated in a high-energy neutron field were studied in order to evaluate a particle size parameter for internal dose evaluation in high-energy accelerator facilities. Argon gas containing DOP aerosols was irradiated by a 65MeV quasi-monoenergetic neutron beam of TIARA. The number size distribution of the DOP aerosols and the activity-weighted size distribution of Cl and Cl aerosols, formed from the (n, 2np) and (n, np) reactions of 
Ar, were measured using an electrical low-pressure impactor. The activity-weighted size distribution of the radioactive aerosols was well explained by the simple attachment model of the radioactive atoms to the DOP aerosols.
Iga, Takashi*; Okumura, Yoshikazu; Kashiwagi, Mieko
JAERI-Tech 2001-028, 16 Pages, 2001/05
JAERI-Tech-2001-028.pdf:0.95MB
no abstracts in English
Sasaki, Yuji; Choppin, G. R.*
Journal of Radioanalytical and Nuclear Chemistry, 246(2), p.267 - 273, 2000/11
Times Cited Count：38 Percentile：89.65(Chemistry, Analytical)no abstracts in English
