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Yoshimura, Nobuyuki*; Toyama, Takeshi*; Shobuda, Yoshihiro; Nakamura, Takeshi*; Omi, Kazuhito*; Kobayashi, Aine*; Okada, Masashi*; Sato, Yoichi*; Nakaya, Tsuyoshi*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.260 - 264, 2023/11
The J-PARC main ring (MR) will be increased to 1.3 MW. To cope with the increase in beam intensity, the intra-bunch feedback system (IBFB) needs to be upgraded to handle higher frequencies up to about 200 MHz. To evaluate the performance and understand the optimal parameters after this upgrade, we are developing a particle tracking simulation that includes the necessary components. The recoherence period induced by chromaticity between tracking simulations and experiments are compared and it cannot be discribed by the simple simulations, and we investigate what mechanisms explain this result. The shift of synchrotron tune caused by longitudinal wakes using tracking simulations are calculated and it find that introducing the effect of longitudinal wakes only does not explain the recoherence period in the experimental results.
scattering length from 
photoproduction on the proton near the reaction thresholdIshikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.
Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05
Times Cited Count：4 Percentile：45.12(Physics, Nuclear)Sakai, Akihiro; Kurosawa, Ryohei*; Nakata, Hisakazu; Okada, Shota; Izumo, Sari; Sato, Makoto*; Kitamura, Yoichi*; Honda, Yasutake*; Takaoka, Katsuki*; Amazawa, Hiroya
JAEA-Technology 2016-019, 134 Pages, 2016/10
JAEA-Technology-2016-019.pdf:8.25MB
Japan Atomic Energy Agency has been developing to design trench disposal facility with impermeable layers in order to dispose of miscellaneous waste. Geomembrane liners have a function that prevent seepage of leachant and collect the leachant. However, the geomembrane liners do not necessarily provide the expected performance due to damage generated when heavy equipment contacts with the liner. Therefore, we studied the impermeable layers having high performance of preventing seepage of leachant including radioactivity taking into account characteristics of low permeable materials and effect of multiple layer structure. As results, we have evaluated that the composite layers composed by a drainage layer, geomembrane liners and a low permeable layer are most effective structure to prevent seepage of leachant. Taking into account disposal of waste including cesium, we also considered zeolite containing sheets for adsorption of cesium were installed in the impermeable layers.
8) induced by supersonic O
beamsOkada, Ryuta; Yoshigoe, Akitaka; Teraoka, Yuden; Yamada, Yoichi*; Sasaki, Masahiro*
Applied Physics Express, 8(2), p.025701_1 - 025701_4, 2015/02
Times Cited Count：7 Percentile：30.95(Physics, Applied)We studied the surface oxidation on a Ge(111)-c(28) surface at room temperature using supersonic oxygen beams as a function of the translational energy of the incident oxygen molecules ranging from 26 meV to 2.3 eV. In situ synchrotron photoemission spectroscopy performed during the oxidation revealed that the surface oxidation terminated with the formation of a sub-monolayer oxide of at most 0.52 ML, for all the beam energies examined. In addition, the oxidation state of the surface oxides was found to depend on the translational energy. These results demonstrate the precise chemical control of the ultrathin surface oxides of Ge(111)-c(28).
synchrotron radiation photoelectron spectroscopy study of the oxidation of the Ge(100)-21 surface by supersonic molecular oxygen beamsYoshigoe, Akitaka; Teraoka, Yuden; Okada, Ryuta; Yamada, Yoichi*; Sasaki, Masahiro*
Journal of Chemical Physics, 141(17), p.174708_1 - 174708_7, 2014/11
Times Cited Count：8 Percentile：29.76(Chemistry, Physical)
synchrotron radiation photoelectron spectroscopy was performed during the oxidation of the Ge(100)-21 surface induced by a molecular oxygen beam with various incident energies up to 2.2 eV from the initial to saturation coverage of surface oxides. The saturation coverage of oxygen on the clean Ge(100) surface was much lower than one monolayer and the oxidation state of Ge was +2 at most. This indicates that the Ge(100) surface is in strong contrast to Si surfaces. The direct adsorption process can be activated by increasing the translational energy, resulting in an increased population of Ge
and a higher final oxygen coverage. Our findings will contribute to the fundamental understanding of oxygen adsorption processes at 300 K from the initial stages to saturated oxidation.
-raysKosuge, Atsushi; Mori, Michiaki; Okada, Hajime; Hajima, Ryoichi; Nagashima, Keisuke
Optics Express (Internet), 22(6), p.6613 - 6619, 2014/03
Times Cited Count：2 Percentile：13.46(Optics)Nowadays, generation of energy-tunable, monochromatic -rays is needed to establish a nondestructive assay method of nuclear fuel materials. The -rays are generated by collision of laser photons stored in a cavity and relativistic electrons. We propose a configuration of an enhancement cavity capable of performing polarization control fabricated by a combination of a four-mirror ring cavity with a small spot inside a cavity and a three-mirror of reflective optics as an image inverter for polarization-selectable -rays. The image inverter introduces a phase shift of specific polarization which can be used to generate an error signal to lock an optical cavity at a resonance condition.
Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 95, 2013/01
Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 100, 2012/01
collisions at 
= 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count：184 Percentile：99.44(Physics, Nuclear)Transverse momentum distributions and yields for 
, and 
in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as 
and 
scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
and Au+Au collisions at 
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count：8 Percentile：49.7(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Tanimoto, Masataka; Taguchi, Taketoshi; Okada, Manabu; Hanawa, Yoshio; Tsuchiya, Kunihiko; Ikeda, Masayuki*; Fujimoto, Yoichi*; Kotov, V.*; Kenzhin, E.*; Kenzhin, Y.*
JAEA-Technology 2011-001, 39 Pages, 2011/03
JAEA-Technology-2011-001.pdf:4.15MB
It is important problem to recycle the irradiated beryllium from the points of effective use of resources, reduction of radioactive waste and nuclear nonproliferation. The recycling of the irradiated beryllium has been considered as the part of the development of Irradiation technology for JMTR refurbishment and restart. The ISTC regular project (K-1566) on recycling technology of irradiated beryllium has been carried out in the Institute of Atomic Energy (IAE), National Nuclear Center of Republic of Kazakhstan (NNC-RK). This paper is described on the transport procedure and transport results of the irradiated beryllium from Japan Atomic Energy Agency (JAEA) to IAE, NNC-RK under the ISTC project.
Ide, Shunsuke; Okada, Hiroyuki*; Hirano, Yoichi*; Todo, Yasushi*; Norimatsu, Takayoshi*; Chikaraishi, Hirotaka*
Purazuma, Kaku Yugo Gakkai-Shi, 79(1), p.65 - 69, 2003/01
no abstracts in English
Konishi, Satoshi; Tobita, Kenji; Nishio, Satoshi; Okada, Hidetoshi*; Kurihara, Ryoichi
Fusion Science and Technology, 41(3), p.817 - 820, 2002/05
no abstracts in English
Nishio, Satoshi; Ushigusa, Kenkichi; Ueda, Shuzo; Polevoi, A.*; Kurita, Genichi; Tobita, Kenji; Kurihara, Ryoichi; Hu, G.; Okada, Hidetoshi*; Murakami, Yoshiki*; et al.
JAERI-Research 2000-029, 105 Pages, 2000/10
JAERI-Research-2000-029.pdf:4.19MB
no abstracts in English
Kurihara, Ryoichi; Nishio, Satoshi; Ueda, Shuzo; Polevoi, A. R.; Aoki, Isao; Ajima, Toshio*; Okada, Hidetoshi*; Hasegawa, Mitsuru*; Ushigusa, Kenkichi
Journal of Plasma and Fusion Research SERIES, Vol.3, p.553 - 557, 2000/00
no abstracts in English
Oshima, Takeshi; Ito, Hisayoshi; Uedono, Akira*; Suzuki, Ryoichi*; Ishida, Yuki*; Takahashi, Tetsuo*; Yoshikawa, Masahito; Kojima, Kazutoshi; Odaira, Toshiyuki*; Nashiyama, Isamu; et al.
Denshi Gijutsu Sogo Kenkyujo Iho, 62(10-11), p.469 - 476, 1999/00
no abstracts in English
Takemura, Tomoyuki*; Shingu, Kazuki*; Sakogaichi, Kaoru*; Nishikawa, Yuji*; Okada, Yoichi*; Nakajima, Toshihide*; Yamashita, Mitsugu*
JNC TJ7420 2005-035, 152 Pages, 1998/03
JNC-TJ7420-2005-035.pdf:27.16MB
The active fault survey tunnel that crossed the Mozumi-Sukenobu fault (MSF) is located at the Kamioka mine, northern Gifu prefecture, Central Japan. The comprehensive study of the active fault, such as the study of the earthquake mechanism and the development of the new initial stress measurement method is done by using this tunnel. One of the purposes of this investigation is to define the three-dimensional distribution of the MSF by geological survey, on the basis of the seismic and geophysical studies on this fault. The other purpose is to develop the new initial stress measurement method.
Takemura, Tomoyuki*; Shingu, Kazuki*; Takahashi, Eiichiro*; Okada, Yoichi*; Takebe, Akimitsu*; Nakajima, Toshihide*; Inoue, Toshio*
JNC TJ7420 2005-033, 128 Pages, 1998/03
JNC-TJ7420-2005-033.pdf:51.98MB
The active fault survey tunnel that crossed the Mozumi-Sukenobu fault (a member of the Atotsugawa fault system) is located at the Kamioka mine, northern Gifu prefecture, Central Japan. The comprehensive study of the active fault is done by using this tunnel. The purpose of this investigation is to define the hydrological characteristics of the Mozumi-Sukenobu fault crush zones. The permeability of the crush zones is measured by the Lugeon test and the simple injection test.
Kiriyama, Hiromitsu; Mori, Michiaki; Daito, Izuru; Kotaki, Hideyuki; Kanazawa, Shuhei; Kondo, Shuji; Nakai, Yoshiki; Yamamoto, Yoichi*; Shimomura, Takuya*; Tanoue, Manabu*; et al.
no journal, ,
We report on a high-peak-power, high-contrast laser system, which combines both conventional Ti:sapphire chirped-pulse amplification and optical parametric chirped-pulse amplification (OPCPA) techniques for use in experiments where relativistic effects dominate the physics. The stretched pulses are amplified in a 3-stage Type-I Bata-Barium Borate OPCPA to an energy level of 10 mJ with an amplification gain of 10
. The output pulses are then amplified in the subsequent Ti:sapphire amplifiers to an energy level of 2.9 J. Pulse compression down to 19 fs duration achieved after amplification indicates a peak power of 80 TW. The pre-pulse contrast is enhanced to better than 
within a few picoseconds before the main pulse. The thermal focal length of about 4 km is obtained.
8) surface at 300 K by supersonic O
molecular beamOkada, Ryuta; Yoshigoe, Akitaka; Teraoka, Yuden; Yamada, Yoichi*; Sasaki, Masahiro*
no journal, ,
Ge has been attracting considerable attention as one of the promising materials for next-generation MOSFET devises because of its high carrier mobility. Understanding of O adsorption process on Ge substrate with various index planes is the most essential to control the quality of oxide layers for these devices. In this research, we employ SR-XPS (synchrotron radiation X-ray photoelectron spectroscopy) measurement to study the oxidation mechanism of the Ge(111) which is known as one of the low index planes. We found the difference in Ge3d profiles of the Ge oxide formed by between supersonic O molecular beam and back filling O. The difference shows that the kinetic energy of the supersonic O molecular beam caused higher coordination of Ge oxide than that of back filling O. This result suggests the presence of new O adsorption states activated by the supersonic O molecular beam.
