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Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Hirakawa, Yasushi; Furukawa, Tomohiro; Hoashi, Eiji*; Fukada, Satoshi*; Suzuki, Akihiro*; Yagi, Juro*; Tsuji, Yoshiyuki*; et al.
Proceedings of Plasma Conference 2014 (PLASMA 2014) (CD-ROM), 2 Pages, 2014/11
In the IFMIF/EVEDA (International Fusion Materials Irradiation Facility/ Engineering Validation and Engineering Design Activity), the validation tests of the EVEDA lithium test loop with the world's highest flow rate of 3000 L/min was succeeded in generating a 100 mm-wide and 25 mm-thick free-surface lithium flow steadily under the IFMIF operation condition of a high-speed of 15 m/s at 250
C in a vacuum of 10 
Pa. Some excellent results of the recent engineering validations including lithium purification, lithium safety, and remote handling technique were obtained, and the engineering design of lithium facility was also evaluated. These results will advance greatly the development of an accelerator-based neutron source to simulate the fusion reactor materials irradiation environment as an important key technology for the development of fusion reactor materials.
Nakano, Tomohide; Shumack, A.*; Maggi, C. F.*; Reinke, M.*; Lawson, K.*; P
tterich, T.*; Brezinsek, S.*; Lipschultz, B.*; Matthews, G. F.*; Chernyshova, M.*; et al.
no journal, ,
In an European tokamak device, JET, an existing high-resolution X-ray crystal spectrometer was upgraded together with installation of the W divertor for the purpose of monitoring the W density in the core plasma. We have identified W
, W
and Mo
lines by comparing the spectrum observed by this spectrometer and that calculated by an atomic structure code. Further, from the intensities of these spectral lines, the W density and the Mo density over an electron density were determined to be 
and 
, respectively. The determined W density was in good agreement with that from another spectrometer. In addition, the plasma effective charge evaluated from the continuum intensity observed by the X-ray spectrometer was in agreement with that from a visible spectrometer within a factor of three. From these agreements, it is probable that the determined W and Mo density are valid. In contrast, the determined W density is only 15% compared with that from an soft X-ray array measurement. This inconsistency will be investigated in the near future.
Idomura, Yasuhiro
no journal, ,
Differences of confinement properties between hydrogen and deuterium plasmas are studied in numerical experiments of ion temperature gradient driven (ITG) turbulence using a full-f gyrokinetic code. Through systematic heating power and plasma size scans, it is found that a Bohm like scaling of the confinement time 
is given by stiff ion temperatur profiles, which are produced by intermittent bursts of avalanche like non-local transprt. Here, 
is the mass of ions and 
is the normalized Larmor radius. From this result, it is shown that the confinement time of the ion temperature gradient turbulence is proportional to the mass of ions.
Hayashi, Nobuhiko; Jeronimo, G.*; Honda, Mitsuru; Shimizu, Katsuhiro; Hoshino, Kazuo; Ide, Shunsuke; Gerardo, G.*; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime
no journal, ,
no abstracts in English
Honda, Mitsuru; Satake, Shinsuke*; Suzuki, Yasuhiro*; Yoshida, Maiko; Hayashi, Nobuhiko; Kamiya, Kensaku; Matsuyama, Akinobu; Shinohara, Koji; Matsunaga, Go; Nakata, Motoki; et al.
no journal, ,
no abstracts in English
Yamamoto, Tsuyoshi; Hatae, Takaki; Yatsuka, Eiichi; Sugie, Tatsuo; Ogawa, Hiroaki; Takeuchi, Masaki; Kitazawa, Sin-iti; Ota, Kazuya*; Hashimoto, Yasunori*; Nakamura, Kitaru*; et al.
no journal, ,
no abstracts in English
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Umeda, Naotaka; Hiratsuka, Junichi; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; et al.
no journal, ,
One of the key issues for producing high current beams in JT-60SA is a uniform production of the negative ions over the large ion extraction area. Non-uniformity of the negative ion beams in the JT-60 negative ion source was improved by modifying the magnetic filter in the source from the PG filter to a tent-shaped filter. In this work, in order to clarify the influence of the magnetic filter modification on arc efficiency and co-electron current is investigated by means of measurements of H ion, H atoms, co-electron current and beam intensity. As a result, the arc efficiency increase due to increase of H ions and H atoms by reduction of filter field. Although the higher electrons current was extracted than the original PG filter, the co-extracted electron could be suppressed by optimization of the bias voltage. This result contributes to extend the pulse duration time up to 100 s for JT-60SA.
Miyata, Yoshiaki; Suzuki, Takahiro; Ide, Shunsuke; Urano, Hajime; Takechi, Manabu
no journal, ,
It is essential for a stable plasma equilibrium control to reconstruct an accurate plasma boundary in tokamak devices. Cauchy Condition Surface (CCS) method is a numerical approach to calculate the spatial distribution of the magnetic flux outside a hypothetical plasma surface and reconstruct the plasma boundary from the magnetic measurements located outside the plasma. It is found that the optimum number of unknown parameters and shape of the CCS for minimizing errors in the reconstructed plasma shape increase in proportion to the plasma size. It is shown that the accuracy of the plasma shape reconstruction greatly improves by using the optimum number of unknown parameters. The assessment of accuracy of plasma shape reconstruction by CCS method in JT-60SA is reported.
Nakamura, Shigetoshi; Shibama, Yusuke; Masaki, Kei; Sakasai, Akira
no journal, ,
no abstracts in English
Shimizu, Katsuhiro; Hoshino, Kazuo; Kawashima, Hisato; Takizuka, Tomonori*
no journal, ,
no abstracts in English
Tanigawa, Hisashi; Someya, Yoji; Nakamura, Makoto; Enoeda, Mikio
no journal, ,
Blanket is located on the vacuum vessel wall in the fusion reactor, and has functions of thermal energy transfer, tritium production and neutron shielding. In ITER, blanket does not have function of tritium production and coolant temperature is low because electric power generation is not planned. In the fusion reactor, the coolant temperature will be higher for the electric power generation and tritium breeding materials will be packed in the blanket. Therefore, safety-related characteristics of blanket are different for ITER and fusion reactor. In this study, thermal hydraulic behaviour in the blanket is analyzed to understand safety-related characteristic.
Toma, Mitsunori; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Honda, Mitsuru; Ide, Shunsuke
no journal, ,
no abstracts in English
Miyato, Naoaki; Yagi, Masatoshi; Scott, B. D.*
no journal, ,
Since the standard gyrokinetic model is constructed by the two-step phase space transformation, fluid moments can be represented in terms of a gyro-center distribution function and gyro-center coordinates in two ways. The representations of fluid moments are called push-forward representations. In the representation used in the standard gyrokinetic formulation, the gyro-center transformation part emerges as the pull-back transformation of the gyro-center distribution function and is separated from the guiding-center transformation part. In the alternative representation, the gyro-center part moves to the parts except the gyro-center distribution function and is combined with the guiding-center part. We compare the two representation by deriving explicit representations of particle flux.
Matsunaga, Go; Suzuki, Yasuhiro*; Shinohara, Koji; Ide, Shunsuke; Urano, Hajime
no journal, ,
no abstracts in English
Shiraishi, Junya; Miyato, Naoaki; Matsunaga, Go
no journal, ,
no abstracts in English
Shibata, Yoshihide; Matsunaga, Go; Sakakibara, Satoru*; Kawano, Yasunori; Isayama, Akihiko; Watanabe, Kiyomasa
no journal, ,
no abstracts in English
Takahashi, Koji; Abe, Ganji; Isozaki, Masami; Ikeda, Ryosuke; Oda, Yasuhisa; Kajiwara, Ken; Sakamoto, Keishi; Kobayashi, Noriyuki*; Iida, Hiromasa*; Komatsuzaki, Manabu*; et al.
no journal, ,
It was analytically obtained that electron cyclotron current drive efficency at 
=0.4
0.6 can be doubled modifying the steering function of millimeter wave launching from the equatorial port from toroidally to poloidally. The design modification of the ITER equatorial launcher enhancing ECCD function is implemented. The millimeter wave design satisfying transmission efficiency more than 99% with the required ploidal beam steering capability is successfully obtained and reflected to the launcher structural design. The millimeter wave design optimization, BSM design modification to allow the required polidal beam steering capability and so on are reported in detail at the conference.
Miki, Kazuhiro; Idomura, Yasuhiro
no journal, ,
Understanding of the energetic particles physics is of great interest in the future burning plasmas. We identify linear dynamics of energetic-particle-induced geodesic acoustic mode (EGAM). Representating bump-on-tail distributions as the energetic particles, we calculate real frequencies and linear growth rates, based on eigenmode analyses. Taking into account of finite-orbit-width (FOW) effects, we estimate the reduction of growth rates of the EGAM due to machine size. Results indicate that the reduction is small, within several percent, for experimentally relevant parameters. Next, applying more general distributions, i.e. slowing down, we examine linear evolution of the EGAM. Here the same q-profile is applied as the DIII-D experiments. Results on the gyrokinetic simulations are compared with the hybrid code ones. Obtained frequencies are similar to those obtained from the hybrid one. Linear growth rates are smaller than those obtained from the hybrid one.
Takechi, Manabu; Matsunaga, Go; Suzuki, Yasuhiro*; Nakamura, Yuji*; Bolzonella, T.*; Ide, Shunsuke; JT-60SA Team
no journal, ,
no abstracts in English
Imazawa, Ryota; Ono, Takehiro; Kawano, Yasunori; Itami, Kiyoshi
no journal, ,
no abstracts in English