JOPSS - Search Results

Journal Articles

Toroidal electric field effect and non-linear effect on electron cyclotron current drive in JT-60U

Suzuki, Takahiro; Ide, Shunsuke; Hamamatsu, Kiyotaka; Petty, C. C.*; Lao, L. L.*; Isayama, Akihiko; Fujita, Takaaki; Ikeda, Yoshitaka; Seki, Masami; Moriyama, Shinichi; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 80(6), p.511 - 515, 2004/06

http://ci.nii.ac.jp/naid/110003827720

no abstracts in English

Journal Articles

Heating and current drive by electron cyclotron waves in JT-60U

Suzuki, Takahiro; Ide, Shunsuke; Hamamatsu, Kiyotaka; Isayama, Akihiko; Fujita, Takaaki; Petty, C. C.*; Ikeda, Yoshitaka; Kajiwara, Ken*; Naito, Osamu; Seki, Masami; et al.

Nuclear Fusion, 44(7), p.699 - 708, 2004/05

https://doi.org/10.1088/0029-5515/44/7/002

Times Cited Count：31 Percentile：69.2(Physics, Fluids & Plasmas)

no abstracts in English

JAEA Reports

Study of non-inductive current drive using high energy neutral beam injection on JT-60U

Oikawa, Toshihiro

JAERI-Research 2003-028, 134 Pages, 2004/01

JAERI-Research-2003-028.pdf:7.73MB

The negative ion based neutral beam (N-NB) driven current density was determined over a wide range of electron temperatures. Theoretical prediction of the NB current drive increasing with beam energy and electron temperature was validated. A record value of NB current drive efficiency was achieved simultaneously with high confinement and high beta at a plasma current of 1.5 MA under a full current drive condition. The experimental validation of NB current drive theory gives greater confidence in predicting the NB current drive in future reactors. However, it was also found that MHD instabilities caused a degradation of NB current drive. A beam-driven instability expelled N-NB fast ions carrying non-inductive current from the central region. The lost N-NB driven current was estimated to be 7 % of the total N-NB driven current. For the neoclassical tearing mode (NTM), comparisons of the measurements with transport code calculations revealed that the loss of fast ions increases with the NTM activity and that fast ions at higher energies suffer larger transport than at lower energies.

Journal Articles

Profile control and plasma start-up by RF waves towards advanced tokamak operation in JT-60U

Takase, Yuichi*; JT-60 Team

AIP Conference Proceedings 694, p.235 - 242, 2003/05

https://doi.org/10.1063/1.1638033

A central electron temperature of 23 keV was obtained by EC wave injection. A highly localized current density profile was obtained by central ECCD, indicating an upper limit on the diffusion coefficient for resonant electrons of $1{rm m^{2}/s}$ . The experimentally obtained current drive figure of merit was lower than theoretical prediction, possibly because of the negative loop voltage induced by overdrive. A comparison of HFS and LFS off-axis ECCD confirmed the theoretically expected trapped particle effect on the current drive efficiency. Offaxis LHCD was used to broaden the qmin radius and the ITB foot radius. N-NBCD was used to shrink the current hole radius. An integrated scenario consisting of (1) a novel plasma start-up method using RF plasma production and induction by vertical field and shaping coils, (2) a noninductive ramp-up stage, and (3) a transition to a high-density, bootstrap-dominated, highconfinement plasma, without the use of the OH solenoid, has been demonstrated. The plasma created by this technique had both internal and edge transport barriers, with $beta_{rm p}=3.6$ ( $epsilonbeta_{rm p}=1$ ), $beta_{rm N}=1.6$ , $H_{rm H98y2}=1.6$ and $f_{rm BS}geq90%$ at $I_{rm p}=0.6$ MA and $n_{rm e}=0.5n_{rm GW}$ .

Journal Articles

Measurement of current driven by electron cyclotron waves in JT-60U

Suzuki, Takahiro; Ide, Shunsuke; Oikawa, Toshihiro; Ikeda, Yoshitaka; Kajiwara, Ken; Isayama, Akihiko; Fujita, Takaaki; Hamamatsu, Kiyotaka; JT-60 Team

Plasma Physics and Controlled Fusion, 44(1), p.1 - 9, 2002/01

https://doi.org/10.1088/0741-3335/44/1/301

Times Cited Count：18 Percentile：50.76(Physics, Fluids & Plasmas)

no abstracts in English

JAEA Reports