High energy negative-ion based neutral beam injection system for JT-60U

Kuriyama, M.; Akino, N.; Araki, M.; Ebisawa, N.; Hanada, M.; Inoue, Takashi; Kawai, M.; Kazawa, M.; Koizumi, J.; Kunieda, Tadashi; Matsuoka, M.; Miyamoto, K.; Mizuno, M.; Mogaki, K.; Ohara, Y.; Ohga, T.; Okumura, Y.; Oohara, H.; Satoh, F.; Suzuki, Takahiro; Takahashi, S.; Takayasu, T.; Usami, H.; Usui, K.; Watanabe, K.; Yamamoto, Masahiro; Yamazaki, Takeshi

doi:10.1016/0920-3796(94)00211-o

Cited by 56 publications

(19 citation statements)

References 2 publications

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“…These experiments will test the idea of a self-sustained fusion plasma, where the energy deposited by fusion-born 3.5 MeV alpha particles eliminates the need for external heating. In order to ignite the plasma, however, a large amount of external heating will still be required, including a set of powerful negative-ion-based neutral beams (N-NB) 2 . Until now, the first and only tokamak equipped with such a system was JT-60U, which operated during 1985–2008 in Naka-city some 100 km north of Tokyo/Japan.…”

Section: Introductionmentioning

confidence: 99%

Simulations tackle abrupt massive migrations of energetic beam ions in a tokamak plasma

et al. 2018

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In the late 1990s, fusion scientists at the Japanese tokamak JT-60U discovered abrupt large-amplitude events during beam-driven deuterium plasma experiments. A large spike in the magnetic fluctuation signal followed by a drop in the neutron emission rate indicates that energetic ions abruptly migrate out of the plasma core during an intense burst of Alfvén waves that lasts only 0.3 ms. With continued beam injection, the energetic ion population recovers until the next event occurs 40–60 ms later. Here we present results from simulations that successfully reproduce multiple migration cycles and report numerical and experimental evidence for the multi-mode nature of these intermittent phenomena. Moreover, we elucidate the role of collisional slow-down and show that the large-amplitude Alfvénic fluctuations can drive magnetic reconnection and induce macroscopic magnetic islands. In this way, our simulations allow us to gradually unravel the underlying physical processes and develop predictive capabilities.

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Section: Introductionmentioning

confidence: 99%

Simulations tackle abrupt massive migrations of energetic beam ions in a tokamak plasma

et al. 2018

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“…The ISPS current rating is summarized in Table 1, the currents are quite high, thus all the ion source power supplies have been installed at high potential stage (500 kV) on a high voltage table (HVT), air insulated, close to the ion source; this solution was possible as the ion source had been moved out of the Torus hall [16]. The acceleration power supply is located in the power supply building and the power is transmitted via a SF 6 gas insulated cable line.…”

Section: The Power Supply Systems Of the Negative Ions Based Nb Injecmentioning

confidence: 99%

The alternative design concept for the ion source power supply of the ITER neutral beam injector

Gaio

Toigo

Lorenzi

et al. 2008

Fusion Engineering and Design

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“…In already existing NBI systems with beam energy above 100 keV, the TL is realized with the SF 6 Gas Insulated Line technology. In the SPIDER TL case, the presence of a large inner conductor (half meter diameter), would make the pressurized TL a complex and costly component; therefore a free air insulated solution has been proposed.…”

Section: Introductionmentioning

confidence: 99%

“…In NBI systems with beam energy above 100 keV [6,7], the TL design is based on Gas Insulated Line technology, using pressurized gas (usually Sulphur Hexafluoride SF 6 ) as insulation media. In the case of the SPIDER TL, the presence of a large inner conductor (half meter diameter), would make the pressurized TL a complex and costly component.…”

Section: Introductionmentioning

confidence: 99%