Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
V
Al alloysSoda, Kazuo*; Harada, Shota*; Hayashi, Toshimitsu*; Kato, Masahiko*; Ishikawa, Fumihiro*; Yamada, Yu*; Fujimori, Shinichi; Saito, Yuji
Materials Transactions, 57(7), p.1040 - 1044, 2016/06
Times Cited Count：2 Percentile：10.95(Materials Science, Multidisciplinary)Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Yoshida, Hidetsugu*; Ono, Takehiro; Kusama, Yoshinori
Review of Scientific Instruments, 83(10), p.10E344_1 - 10E344_3, 2012/10
Times Cited Count：15 Percentile：54.44(Instruments & Instrumentation)A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).
Hatae, Takaki; Hayashi, Toshimitsu; Yatsuka, Eiichi; Kajita, Shin*; Yoshida, Hidetsugu*; Fujita, Hisanori*; Nakatsuka, Masahiro*; Yahagi, Kenichi*; Shinobu, Katsuya*; Ono, Takehiro; et al.
Journal of Plasma and Fusion Research SERIES, Vol.9, p.253 - 258, 2010/08
Liu, Q.; Homma, Toshimitsu; Nishimaki, Yuichiro*; Hayashi, Hiroko*; Terakado, Masato*; Tamura, Satoshi*
JAEA-Data/Code 2010-001, 57 Pages, 2010/03
JAEA-Data-Code-2010-001.pdf:16.81MB
For a risk assessment model of an engineering system, the uncertainties in the model inputs propagate through the model and lead to the uncertainty in the model output. In order to evaluate the model output uncertainty and the contribution of each model input to the output uncertainty, the computer code GSALab, which is based on Monte Carlo simulations, has been developed. It is composed of three parts, namely, random samples generation, uncertainty analysis and sensitivity analysis. In the part of sensitivity analysis, several global sensitivity indicators, including the popularly used variance-based indicators, are implemented. In addition, the GUI (Graphical User Interface) of GSALab has been developed for the user's convenience. In addition to risk assessment models, it is also possible to use GSALab for uncertainty and sensitivity analysis of a wide class of mathematical models.
Kondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo
Plasma and Fusion Research (Internet), 2, p.S1111_1 - S1111_4, 2007/11
A diagnostic of fusion-generated alpha-particles is important to understand burning plasma physics, however, an effective measurement method has not yet been established. A collective Thomson scattering (CTS) diagnostic CO
laser is being developed to establish a diagnostic method of confined alpha-particles. To realize the CTS diagnostic, a high-repetition Transversely Excited Atmospheric (TEA) CO has been developed. In order to obtain single-mode output, which is needed for the CTS diagnostic, seed laser is injected to the cavity with an unstable resonator. Using this technique, output energy of 17J with the frequency of 15 Hz has been achieved with single-mode output. These results gives a prospect for the CTS diagnostic on International Thermonuclear Experimental Reactor (ITER), which requires energy of 20 J with the repetition rate of 40 Hz. Proof-of-principle test is being performed with the improved laser system on the JT-60U tokamak.
laserKondoh, Takashi; Kawano, Yasunori; Hatae, Takaki; Sugie, Tatsuo; Hayashi, Toshimitsu; Kusama, Yoshinori
NIFS-PROC-68, p.126 - 129, 2007/09
High power and high repetition CO laser has been developed for collective Thomson scattering (CTS) diagnostic to establish a diagnostic method of confined 
-particles in burning plasmas. Pulse energy of 17 J at a repetition rate of 15 Hz has been achieved in a single-mode operation. This result gives a prospect for the CTS diagnostic on International Thermonuclear Experimental Reactor (ITER), which requires energy of 20 J with repetition rate of 40 Hz. The laser injection test into the vacuum vessel of the JT-60U tokamak has been carried out to check the electric noise and stray signals of the receiver system using the new CO laser without plasma. As a result, electrical noise has been decreased, however, stray signal due to multimode oscillation has been observed in about 30% of the pulses and a further improvement of the laser is needed.
laser collective Thomson scattering diagnostic of -particles in burning plasmasKondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo; Hirata, Mafumi*; Miura, Yukitoshi
Fusion Science and Technology, 51(2T), p.62 - 64, 2007/02
Times Cited Count：5 Percentile：36.27(Nuclear Science & Technology)A diagnostic of fusion-generated -particles is important for the understanding of their contribution to plasma heating and plasma instabilities in burning plasmas. However, an effective measurement method has not yet been established. In International Thermonuclear Experimental Reactor (ITER), measurement of velocity and spatial distributions of confined -particles requires temporal resolution of 0.1 s and spatial resolution of a/10, where a is the plasma minor radius of ITER. A collective Thomson scattering (CTS) diagnostic for the measurement of particles is being developed using carbon dioxide (CO) lasers. The CTS based on the CO laser (wavelength 10.6 
m) has an advantage of small plasma refraction, simplifying the tracking of the scattered radiation. To realize the CTS diagnostic, a high-repetition Transversely Excited Atmospheric (TEA) CO laser is being developed. The laser was designed based on a commercially available laser, TEA CO marking laser. Maximum output energy of 36 J has been obtained with a cavity configuration of stable resonator. In order to obtain single-mode output, which is needed for CTS diagnostic, seed laser is injected to the cavity with unstable resonator. Using this technique, output energy of 10 J at a frequency of 10 Hz has been achieved with single-mode output. Proof-of-principle test will be performed with the improved laser system on the JT-60U tokamak. In this paper, we will describe development of the new TEA laser system, measurement results of the CTS on the JT-60U tokamak. Application of the CTS diagnostic to the mirror systems will be also described.
laser for alpha-particle diagnosticKondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo
Tokutei Ryoiki Purazuma Nensho No Tameno Senshin Keisoku News Letter, (5), P. 2, 2006/11
no abstracts in English
laser for collective Thomson scattering diagnostic of particles in burning plasmasKondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo; Miura, Yukitoshi; Koseki, Ryoji*; Kawahara, Yoshihiro*
Review of Scientific Instruments, 77(10), p.10E505_1 - 10E505_3, 2006/10
Times Cited Count：6 Percentile：33.17(Instruments & Instrumentation)A collective Thomson scattering (CTS) technique based on a pulsed CO laser is being developed in order to establish a diagnostic method of confined -particles in burning plasmas. In International Thermonuclear Experimental Reactor (ITER), measurement of velocity and spatial distributions of confined -particles requires temporal resolution of 0.1 s and spatial resolution of a/10, where a is plasma minor radius. A new laser system (Energy 
10J, repetition 10Hz) has been developed based on a commercially available laser (Shibuya Kogyo Co., Ltd, SEL4000) to meet the requirement of temporal resolution of ITER and to improve a signal-to-noise ratio. The laser has unstable resonator with a cavity length of 4 m and discharge electrodes with heat exchanger of laser gas for high-repetition operation. Proof-of-principle test of the CTS technique will be performed with the new laser system on JT-60U (JAEA Tokamak 60 - Upgrade). This work was supported by Grant-in-Aid for Scientific Research on Priority Areas "Advanced Diagnostics for Burning Plasmas" from Ministry of Education, Culture, Sports, Science and Technology, No.16082210.
-particle diagnostic in burning plasmaKondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo
no journal, ,
no abstracts in English
-particle in burning plasmaKondoh, Takashi; Hayashi, Toshimitsu; Kawano, Yasunori; Kusama, Yoshinori; Sugie, Tatsuo; Miura, Yukitoshi
no journal, ,
no abstracts in English
Hatae, Takaki; Kajita, Shin*; Hayashi, Toshimitsu; Yoshida, Hidetsugu*; Fujita, Hisanori*; Nakatsuka, Masahiro*; Ebisawa, Katsuyuki*; Kusama, Yoshinori
no journal, ,
no abstracts in English
Kawano, Yasunori; Ishikawa, Masao; Kusama, Yoshinori; Hayashi, Toshimitsu; Ono, Takehiro; Ebisawa, Katsuyuki*; Wakabayashi, Kuniaki*; Kiyohara, Motosuke*
no journal, ,
no abstracts in English
Miyamoto, Seiji; Hayashi, Nobuhiko; Oyama, Naoyuki; Takenaga, Hidenobu; Toshimitsu, Shinichi; Sugie, Tatsuo; Kusama, Yoshinori; Yoshino, Ryuji
no journal, ,
In the operation of ITER, transition from the high confinement (H) mode to the low confinement (L) mode (H-L transition) is serious disturbance to control system, and therefore it is an important issue in operation scenario development to model the plasma behavior during the transition. Especially, the analysis must include neutral particles in plasma behavior. In the ITER current ramp-down scenario, the plasma is kept in H-mode, and thereby in low internal inductance, to leave a control margin. Then the plasma goes to L-mode at the final stage of the discharge. When the plasma particles emitted at the H-L transition flow back to the plasma as neutrals, the discharge may lead to a radiation collapse if the pumping capacity is too low. It is therefore required to perform a simulation including a model of fueling and pumping system. We did not take into account the scrape-off-layer (SOL) and divertor models previously. However, these models influence the plasma particle behavior through neutralization of ions in front of the divertor target and re-ionization of neutrals in the SOL. In the presentation, we describe the implementation of the SOL and divertor models in the tokamak simulation code (TSC) and the effect on the plasma and neutral behavior.
Miyamoto, Seiji; Nakamura, Yukiharu*; Toshimitsu, Shinichi; Sugie, Tatsuo; Kusama, Yoshinori; Yoshino, Ryuji; Hayashi, Nobuhiko; Oyama, Naoyuki; Takenaga, Hidenobu; Oikawa, Toshihiro*
no journal, ,
Development of ITER operation scenario using TSC code in JAEA is reviewed. TSC is a numerical code to simulate plasma evolution solving the MHD equation in an axisymmetric cylindrical coordinates. We have incorporated numerical models of electron cyclotron heating (ECH) / current drive (ECCD) and neutral beam injection (NBI) heating / current drive into the TSC code. Using the incorporated ECH/ECCD model, flux saving during plasma current ramp-up by EC is discussed. It is shown that resistive flux is effectively reduced due to heating of electron by EC. Recently, we are incorporating a neutral particle fueling and pumping model for studying effect of H-L transition on the poloidal field coil system of ITER size machine. A plan of neutral model development in TSC is also presented.
Kawano, Yasunori; Ishikawa, Masao; Sato, Kazuyoshi; Imazawa, Ryota; Kusama, Yoshinori; Hayashi, Toshimitsu; Ono, Takehiro; Ebisawa, Katsuyuki*; Wakabayashi, Kuniaki*; Hiramatsu, Miho*; et al.
no journal, ,
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu*; Ono, Takehiro; Kusama, Yoshinori
no journal, ,
A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).
Kusama, Yoshinori; Kondoh, Takashi; Ishikawa, Masao; Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Ono, Takehiro; Kawano, Yasunori; Imazawa, Ryota; Ogawa, Hiroaki; et al.
no journal, ,
no abstracts in English
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Ono, Takehiro; Kusama, Yoshinori
no journal, ,
Kawano, Yasunori; Kondoh, Takashi; Ishikawa, Masao; Hatae, Takaki; Yatsuka, Eiichi; Imazawa, Ryota; Ogawa, Hiroaki; Sugie, Tatsuo; Takeuchi, Masaki; Sato, Kazuyoshi; et al.
no journal, ,
Recent progress in development of ITER diagnostic systems in Japan is presented as briefly shown below. (1) Microfission Chamber: A prototyping of vacuum feedthrough showed that the vacuum leak rate satisfies that of ITER requirement. (2) Thomson scattering (edge): A new method proposed for the measurement of anisotropic electron temperature was presented. (3) Poloidal Polarimeter: Measurement accuracy of the poloidal polarimeter was evaluated so that the accuracy of resultant current profile can satisfy the ITER measurement requirement. (4) Impurity influx monitor (divertor): By improvement of the design of equatorial port optics, expected detected light was 16 times increased in comparison with that of the previous design. (5) Divertor thermocouples (outer target): Investigation was started about the fixation method of the thermocouple on the side of divertor outer target. (6) Divertor IR thermography: Conceptual design activity was started for equatorial port optics.
