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Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Nakamura, Tetsuya*; Imaizumi, Mitsuru*; Sato, Shinichiro; Sugaya, Takeyoshi*; Mochizuki, Toru*; Okano, Yoshinobu*; Oshima, Takeshi
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.73 - 76, 2015/11
The radiation effect on GaAs p-i-n solar cells with quantum dot (QD) in the i-layer was investigated. In a previous work, we particularly noted the degradation of fill-factor (FF) for the QD cells. In this work, to clarify the reason of the FF degradation in QD cells, generation current due to low-energy proton irradiation, which we call ion beam induced current (IBIC), was observed to characterize behavior of the generated minority carrier by the protons in the depletion region where QDs are located. The energy of protons was adjusted to damage the depletion region, and decrease of generation current was measured during the proton irradiation. The results suggest that the serious degradation of FF is caused by a decrease of the carrier collection efficiency in the depletion region due to proton damage.
Fitriana, Y.*; Shinohara, Shinobu*; Sato, Katsuya; Narumi, Issey*; Saito, Tsutomu*
Applied Entomology and Zoology, 50(1), p.123 - 129, 2015/02
Times Cited Count:0 Percentile:1.75(Chemistry, Physical)Yokota, Wataru; Sato, Takahiro; Kamiya, Tomihiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Funayama, Tomoo; Sakashita, Tetsuya; et al.
JAEA-Technology 2014-018, 103 Pages, 2014/09
The world's first microbeam focusing technology for heavy ions of hundreds MeV accelerated by a cyclotron has been developed at the TIARA facility in the Takasaki Advanced Radiation Research Institute of the Japan Atomic Energy Agency. The technology enables us to form a microbeam of less than 1 m in diameter and to shoot a specified point on a target by one ion (single-ion hit) with spatial accuracy of microbeam size. In the course of the development, a cyclotron technology to accelerate a small energy-spread beam of hundres MeV, which is necessary for focusing to 1 m, has been developed as well as a beam focusing apparatus, beam size measurement and so forth based on the several-MeV microbeam/single-ion hit system of the TIARA electrostatic accelerators. Applicability of the technologies was examined by actual use in irradiation experiment and the result were fed back to them. This paper reports the process and the results of the development over ten years.
Kada, Wataru*; Iwamoto, Naoya; Sato, Takahiro; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Koka, Masashi; Oshima, Takeshi; Jaki, M.*; Kamiya, Tomihiro
Nuclear Instruments and Methods in Physics Research B, 331, p.113 - 116, 2014/07
Times Cited Count:23 Percentile:86.56(Instruments & Instrumentation)no abstracts in English
Shinohara, Shinobu*; Fitriana, Y.*; Sato, Katsuya; Narumi, Issey*; Saito, Tsutomu*
FEMS Microbiology Letters, 349(1), p.54 - 60, 2013/12
Times Cited Count:10 Percentile:29.65(Microbiology)Onoda, Shinobu; Hasuike, Atsushi*; Nabeshima, Yoshiaki*; Sasaki, Hajime*; Yajima, Kotaro*; Sato, Shinichiro; Oshima, Takeshi
IEEE Transactions on Nuclear Science, 60(6), p.4446 - 4450, 2013/12
Times Cited Count:38 Percentile:94.87(Engineering, Electrical & Electronic)no abstracts in English
Kada, Wataru; Kamiya, Tomihiro; Iwamoto, Naoya; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Makino, Takahiro; Koka, Masashi; Sato, Takahiro; Jaki, M.*; et al.
Transactions of the Materials Research Society of Japan, 38(2), p.279 - 282, 2013/07
Diamond is interested by many researchers as an excellent candidate material with advantages in the radiation-hardness. For the time-resolved detection of single-ions with several hundred MeV, transmission E detector using thin film CVD diamond is now under investigation for the futuristic utilization in a microbeam line of the AVF cyclotron at JAEA/Takasaki TIARA facility as replacing materials of the beam extraction window. In this research, a Single Crystalline (SC) 50 m thick CVD diamond film ion detector was fabricated for the investigation of the responses and radiation hardness under the focused ion microbeam irradiation. Transient Ion Beam Induced Current (TIBIC) experiment was executed by single hit irradiation of 15 MeV O scanning area of 50 m and the transient signals with time width of several nano-secounds were consecutively recorded by a high speed (15 GHz) Digital Storage Oscilloscope during the irradiation. The decreases in the individual pulse height was observed by increasing the total amount of the ion dose irradiated in the focused area. These changes were recovered in temporal conversion of applied bias voltages thus trend of decrease were able to be controlled by changing bias settings and irradiation conditions during the experiments.
Saito, Tsutomu*; Shinohara, Shinobu*; Sato, Katsuya; Narumi, Issei
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 109, 2013/01
Kada, Wataru; Sato, Takahiro; Makino, Takahiro; Onoda, Shinobu; Koka, Masashi; Oshima, Takeshi; Kamiya, Tomihiro; Grilj, V.*; Skukan, N.*; Jaksic, M.*
KEK Proceedings 2012-8, p.89 - 98, 2012/12
Transmissive particle detectors using thin-film diamond were newly developed for the individual detection of single-hit of heavy ions. Two type of the detectors were developed using poly- and single-crystalline diamond films with thickness of upper 50 m, which could be alternative candidate material of beam-extraction window. The detectors were irradiated at off- and on-line environment using alpha-particle sources and microbeam lines of two tandem accelerators placed at TARRI, JAEA and RBI. From point of view in the response of energy spectrum and detection efficiency, it was experimentally examined that the thin-film of single-crystalline diamond was well respond to the irradiation of single ions with energy of several MeV.
Toyoshima, Yoshiyuki*; Takahashi, Akemi*; Tanaka, Hisaki*; Watanabe, Jun*; Mogi, Yoshinobu*; Yamazaki, Tatsuo*; Hamada, Ryoko*; Iwashita, Kazuhiro*; Sato, Katsuya; Narumi, Issei
Mutation Research; Fundamental and Molecular Mechanisms of Mutagenesis, 740(1-2), p.43 - 49, 2012/12
Times Cited Count:16 Percentile:49.39(Biotechnology & Applied Microbiology)Kada, Wataru; Sato, Takahiro; Iwamoto, Naoya; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Makino, Takahiro; Koka, Masashi; Jaki, M.*; Oshima, Takeshi; et al.
Proceedings of 10th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-10) (Internet), p.70 - 73, 2012/12
Thin film CVD diamond detector is now under investigation for the utilization as a transmission detector for ionized particle in single-ion-hit by replacing materials of the beam extraction window in a microbeam line of the AVF cyclotron at JAEA/Takasaki. In this research, a spectroscopy-grade 50 m thick-film Single Crystalline (SC) CVD diamond detector with size of 4.6 mm 4.6 mm was characterized using Ion Beam Induced Charge (IBIC) and Transient Ion Beam Induced Current (TIBIC) systems. The detector was irradiated with 1-3 MeV H and 15 MeV O microbeams. Significant decrease of pulse height of IBIC signals was observed at 15 MeV O irradiation, however, this peak degradation easily recovered in a short time by release of bias voltages. This temporal degradation effect was enhanced in areas damaged by previous ion irradiation. Therefore, the temporal peak degradation seems to be caused by the polarization effect due to charge captured by defects in diamond or/and at the surface.
Saito, Tsutomu*; Shinohara, Shinobu*; Sato, Katsuya; Narumi, Issei
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 112, 2012/01
Hirao, Toshio; Onoda, Shinobu; Oikawa, Masakazu*; Sato, Takahiro; Kamiya, Tomihiro; Oshima, Takeshi
Nuclear Instruments and Methods in Physics Research B, 267(12-13), p.2216 - 2218, 2009/06
Times Cited Count:11 Percentile:59.93(Instruments & Instrumentation)Single-Event Effects (SEEs) are triggered when an energetic heavy ion traverses a sensitive area in electric devices. Since the SEEs occur due to dense charge which is created along to ion track within the order of picoseconds, the measurement of such a high speed current signals is very important. Furthermore, the size of dense charge and their concentration depend on LET as well as energy of incident ions. This means that the transient currents induced in electronic devices by incidence of ions with various energies and LETs should be investigated to clarify the mechanism of SEEs for electronic devices. Especially, the evaluations using heavy ions with high energies more than a several hundred MeVs are very important to understand the mechanism of SEEs observed in space. For this aim, we have developed an irradiation system of focused heavy ion microbeams at a several hundreds of MeVs at JAEA. In this paper, we study transient currents induced in Si photodiodes using the focused heavy ion microbeam irradiation system. The mapping of charge collected from the photodiodes irradiated with 260 MeV Ne ion microbeams, which is firstly observed in the world, will be presented. In addition, the difference in transient currents induced by ions at several hundred MeVs from ions at tens MeVs is discussed using TCAD (Technology Computer Aided Design) and GUN theorem.
Aihara, Jun; Ueta, Shohei; Mozumi, Yasuhiro; Sato, Hiroyuki; Motohashi, Yoshinobu*; Sawa, Kazuhiro
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.416 - 422, 2007/09
In high temperature gas-cooled reactors (HTGRs), coated particles are used as fuels. For upgrading HTGR technologies, present SiC coating layer which is used as the 3rd layer could be replaced with ZrC coating layer which have much higher temperature stability in addition to higher resistance to chemical attack by fission product palladium than the SiC coating layer. The ZrC layer could deform plastically at high temperatures. Therefore, the Japan Atomic Energy Agency modified an existing pressure vessel failure fraction calculation code to treat the plastic deformation of the 3rd layer in order to predict failure fraction of ZrC coated particle under irradiation. Finite element method is employed to calculate the stress in each coating layer. The pressure vessel failure fraction of the coated fuel particles under normal operating condition of GTHTR300C is calculated by the modified code. The failure fraction is evaluated as low as 3.510.
Hatae, Takaki; Nakatsuka, Masahiro*; Yoshida, Hidetsugu*; Ebisawa, Katsuyuki*; Kusama, Yoshinori; Sato, Kazuyoshi; Katsunuma, Atsushi*; Kubomura, Hiroyuki*; Shinobu, Katsuya*
Fusion Science and Technology, 51(2T), p.58 - 61, 2007/02
Times Cited Count:6 Percentile:42.6(Nuclear Science & Technology)no abstracts in English
Oshima, Takeshi; Onoda, Shinobu; Oikawa, Masakazu*; Sato, Takahiro; Hirao, Toshio; Kamiya, Tomihiro; Ito, Hisayoshi
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 13, 2007/02
no abstracts in English
Oshima, Takeshi; Sato, Takahiro; Oikawa, Masakazu; Onoda, Shinobu; Hishiki, Shigeomi; Hirao, Toshio; Kamiya, Tomihiro; Yokoyama, Takuro*; Sakamoto, Airi*; Tanaka, Reisaburo*; et al.
Materials Science Forum, 556-557, p.913 - 916, 2007/00
Times Cited Count:4 Percentile:76.87no abstracts in English
Iwamoto, Naoya; Oshima, Takeshi; Sato, Takahiro; Oikawa, Masakazu*; Onoda, Shinobu; Hishiki, Shigeomi; Hirao, Toshio; Kamiya, Tomihiro; Yokoyama, Takuro*; Sakamoto, Airi*; et al.
Proceedings of 7th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-7), p.185 - 188, 2006/10
no abstracts in English
Aso, Naofumi*; Owada, Kenji; Watanuki, Tetsu; Machida, Akihiko; Omura, Ayako; Inami, Toshiya; Homma, Yoshiya*; Shiokawa, Yoshinobu*; Hirota, Kazuma*; Sato, Noriaki*
Journal of the Physical Society of Japan, 75(Suppl.), p.88 - 90, 2006/08
no abstracts in English