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Miyato, Naoaki; Scott, B. D.*; Yagi, Masatoshi
Proceedings of Plasma Conference 2011 (PLASMA 2011) (CD-ROM), 2 Pages, 2011/11
Seki, Yohji; Hirose, Takanori; Tanigawa, Hisashi; Enoeda, Mikio
Proceedings of Plasma Conference 2011 (PLASMA 2011) (CD-ROM), 2 Pages, 2011/11
Development of test blanket module (TBM) with a water cooled solid breeder is being performed as the primary candidate of ITER-TBM of Japan. Prior to the installation of each TBM, it is necessary to develop the capability of the prediction analyses of all essential functions of the blanket to validate the analyses tools by the TBM. Especially the prediction tool of tritium concentration in the blanket system is one of the most important issues to control tritium recovery. From this view point, this paper discusses the flow phenomena and the tritium transport of the helium purge gas in the pebble bed. By prediction of purge gas flow using a numerical simulation, the result indicates tritium concentration depended on the position of the breeder layer. Namely, the large concentration still remains near the wall with approaching to an outlet.
Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi; Iuchi, Hiroshi; Kanemura, Takuji; Ida, Mizuho; Watanabe, Kazuyoshi; Horiike, Hiroshi*; Yamaoka, Nobuo*; Matsushita, Izuru*; et al.
Proceedings of Plasma Conference 2011 (PLASMA 2011) (CD-ROM), 2 Pages, 2011/11
The EVEDA Li test loop (ELTL) successfully completed its construction and commissioning in the frame work of the IFMIF/EVEDA as one of the ITER-BA. The construction was started on Nov. 2009 in the O-arai site of the Japan Atomic Energy Agency and completed on the middle of Nov. 2010. In the commissioning conducted subsequently, the following tests were performed: (1) Li ingots installation into the ELTL, (2) Li charging and draining operation, (3) Li circulation tests. In a final phase of the circulation test, stable liquid Li flow at a velocity of 5 m/s was successfully achieved.
Tsujimoto, Kazufumi
Proceedings of Plasma Conference 2011 (PLASMA 2011) (CD-ROM), 2 Pages, 2011/11
Neutron beam is used for a wide variety of scientific and engineering research, such as materials and life science, and industrial applications. There are three kinds of neutron sources: (1) isotopic neutron source, (2) reactor sources, and (3) accelerator-based neutron sources. Recently, high intensity spallation neutron sources with high energy proton accelerator became to offer similar capabilities to research reactors, as well as a few extra features. In Japan, the JSNS (Japan Spallation Neutron Source) was constructed and operated at J-PARC (Japan Proton Accelerator Research Complex). Moreover, as future utilization of spallation neutron, research and development for accelerator-driven subcritical system have been performed.
Kawashima, Hisato; Shimizu, Katsuhiro; Hoshino, Kazuo; Takizuka, Tomonori*; Sakurai, Shinji
no journal, ,
For SONIC simulation on JT-60SA divertor, the heat flux limiter is introduced in the ion parallel heat transport besides electron one. Changing the limit factor from 
= 0.5 to 10, density decrement and temperature increment in the edge-plasma are remarkable at = 0.5 in comparison with a case without limiter. Sensitivity on the radial particle or thermal diffusivity is surveyed with range of D = 0.1
1 m
/s and 
= 0.12 m/s. Divertor heat flux increases from 7.5 to 10.5 MW/m with decrease of D. This sensitivity is stronger than that for .
Nishikino, Masaharu; Yamamoto, Minoru*; Hasegawa, Noboru; Tomita, Takuro*; Terakawa, Kota*; Minami, Yasuo*; Takei, Ryota*; Onishi, Ryo*; Ishino, Masahiko; Kaihori, Takeshi; et al.
no journal, ,
The X-ray reflective imaging using a soft X-ray laser was used to observe the early stage of the femtosecond laser ablation process on the platinum. The fluence dependence of the soft X-ray reflectivity is classified into three regions: (1) strongly excited, (2) moderately excited, and (3) weakly excited regions. In strongly excited region, the rapid reduction of the reflectivity due to the explosive evaporation in the ablation process of the material surface was observed. In the moderately excited region, the reflectivity reduction is far slower than that in the strongly excited region. The reflectivity reduction is seemed to be caused by the growth of surface roughness on the ablation front because of the formation of nano-bubbles in the irradiated material.
Sasaki, Akira
no journal, ,
no abstracts in English
Urano, Hajime
no journal, ,
The Nuclear Fusion Award 2011 is reported. The awarded paper "H. Urano, et al, Dimensionless parameter dependence of H-mode pedestal width using hydrogen and deuterium plasmas in JT-60U", Nucl. Fusion, 48, 045008 (2008)" clarified the dimensionless parameter dependence of H-mode pedestal width by introducing the different fuel ion species. This result is used for the prediction of the pedestal width on ITER standard H-mode plasma.
Yanagi, Yutaka*; Shibui, Masanao*; Kanahara, Toshio*; Mochida, Tsutomu*; Ejiri, Mitsuru*; Asano, Shiro*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira
no journal, ,
JT-60SA Vacuum Vessel (VV) has D-shaped cross section and double-walled structure. It consists of the inner and outer wall reinforced by poloidal ribs and is made of SUS316L (Co
0.05wt%). The welding outer wall on rib (so called continuous plug) is performed from the outside of double-wall. Since it is difficult to confirm the penetration bead from the inside of double-wall, an incomplete penetration is assumed to be included in this welded joint. In this study, the fatigue test of continuous plug welded joint with an artificial incomplete penetration was performed to investigate the effect of the incomplete penetration on fatigue behavior and fatigue strength.
Koizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Chida, Yutaka; Iguchi, Masahide
no journal, ,
no abstracts in English
Kamiya, Kensaku; Honda, Mitsuru; Urano, Hajime; Yoshida, Maiko; Sakamoto, Yoshiteru; Matsunaga, Go; Oyama, Naoyuki; Koide, Yoshihiko; Kamada, Yutaka
no journal, ,
Depending on the direction of the external tangential momentum input, substantial changes in not only toroidal but also poloidal flows for the carbon impurity ions are observed at around the Er-well region. The shear in the edge Er becomes wider in the co-NBI case, while the edge Er-well becomes deeper in the counter-NBI case.
Shiraishi, Junya; Aiba, Nobuyuki; Yagi, Masatoshi
no journal, ,
no abstracts in English
Kobayashi, Takayuki; Isayama, Akihiko; Hoshino, Katsumichi; Yokokura, Kenji; Shimono, Mitsugu; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; et al.
no journal, ,
Design and development of high-power long-pulse electron cyclotron heating and current drive system for JT-60SA have been progressed. High power transmission test using newly developed components with a waveguide inner diameter of 60.3 mm was carried out. A conditioning operation was progressed to 5 s with an output power of 0.5 MW, so far, within a few weeks without significant trouble. The other progress was made to develop the dual frequency system with an additional frequency of 137.6 GHz in order to enhance operation regime. Output power higher than 1 MW with oscillation efficiency much higher than 30% was obtained for the design of a dual frequency gyrotron for both 110 GHz and 137.6 GHz.
Kotaki, Hideyuki; Kando, Masaki; Pirozhkov, A. S.; Kawase, Keigo*; Esirkepov, T. Z.; Fukuda, Yuji; Kiriyama, Hiromitsu; Okada, Hajime; Daito, Izuru; Kameshima, Takashi*; et al.
no journal, ,
no abstracts in English
Nishitani, Takeo; Tobita, Kenji; Ishikawa, Masao; Shinohara, Koji
no journal, ,
no abstracts in English
Mori, Masahiro
no journal, ,
no abstracts in English
Shinto, Katsuhiro; Wada, Motoi*; Nishida, Tomoaki*; Kisaki, Masashi*; Tsumori, Katsuyoshi*; Nishiura, Masaki*; Kaneko, Osamu*; Sasao, Mamiko*
no journal, ,
We have proposed a negative ion beam probe system as a new scheme to diagnose beam profiles of high power positive ion beams. We show the present status of the proof-of-principle experiment for the negative ion beam probe system performed at NIFS NBI test stand. A negative hydrogen ion source which produces a rectangular shape beam was installed at the diagnostic chamber in the NBI test stand and the total current of H
beam extracted from the ion source was measured. We obtained the total H beam current of 10 
A with the beam energy of 3 kV.
Nakamura, Tatsufumi; Esirkepov, T. Z.; Koga, J. K.; Pirozhkov, A. S.; Bulanov, S. V.; Kando, Masaki
no journal, ,
The concept of flying mirror is proposed to increase the laser irradiance, and generating the tunable compact X-ray source. The amplification factor is expressed by using Lorentz factor corresponding to the phase velocity of plasma wave 
, as 
. Although the phase velocity of plasma wave is approximated as the laser group velocity in the one-dimensional model, it becomes lower at near the wave-breaking. In this study, we elucidate the plasma phase velocity including multi-dimensional effect and its nonlinear evolution towards wave-breaking by using two-dimensional PIC simulations. Its dependence on laser intensity, spot size, pulse duration, and plasma density is explored.
Yatsuka, Eiichi; Hatae, Takaki; Kusama, Yoshinori
no journal, ,
no abstracts in English
Ejiri, Mitsuru*; Kitamura, Kazunori*; Araki, Takao*; Omori, Junji*; Asano, Shiro*; Hayakawa, Atsuro*; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira
no journal, ,
In the operation of tokamak, such loads as electromagnetic and seismic are assumed to be imposed on the vacuum vessel (VV), and not a little thermal expansion takes place when VV is baked. The gravity support leg (GS) has to support the loads described above in addition to the dead weight of VV including in-vessel components and compensate deformation. The GS is equipped with plate spring (PS) to have both stiffness and flexibility. In this study, the buckling strength of the PSs was evaluated. The effect of the initial imperfection of the PSs which is assumed to result from machining or welding process on the buckling strength was also studied. It is concluded that GS has sufficient buckling strength against assumed initial imperfections.