Current ramps in tokamaks; From present experiments to ITER scenarios

トカマク電流立ち上げ; 近年の実験からITERシナリオへ

Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; 福山 淳*; Garcia, J.*; Gribov, Y. V.*; 林 伸彦; Hobirk, J.*; Hogeweij, D.*; 本多 充; Hutchinson, I.*; Jackson, G.*; Kavin, A. A.*; Kessel, C. E.*; Khayrutdinov, R. R.*; Kchl, F.*; Labate, C.*; Leonov, V. M.*; Litaudon, X.*; Lomas, P. J.*; Lnnroth, J.*; Luce, T.*; Lukash, V. E.*; Mattei, M.*; Mikkelsen, D. R.*; 宮本 斉児; 中村 幸治*; Nunes, I.*; Parail, V.*; Pereverzev, G. V.*; Peysson, Y.*; Polevoi, A.*; Politzer, P.*; Schneider, M.*; Sips, G.*; Tardini, G.*; Voitsekhovitch, I.*; Wolfe, S. M.*; Zhogolev, V. E.*; ASDEX Upgrade Team*; C-Mod Team*; DIII-D Team*; JET-EFDA Contributors*; JT-60Uチーム; Tore Supra Teams*; Contributors of the EU-ITM ITER Scenario Modelling Group*; ITPA "Integrated Operation Scenarios" Group*; ITPA "Transport and Confinement" Group*

Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; Fukuyama, Atsushi*; Garcia, J.*; Gribov, Y. V.*; Hayashi, Nobuhiko; Hobirk, J.*; Hogeweij, D.*; Honda, Mitsuru; Hutchinson, I.*; Jackson, G.*; Kavin, A. A.*; Kessel, C. E.*; Khayrutdinov, R. R.*; Kchl, F.*; Labate, C.*; Leonov, V. M.*; Litaudon, X.*; Lomas, P. J.*; Lnnroth, J.*; Luce, T.*; Lukash, V. E.*; Mattei, M.*; Mikkelsen, D. R.*; Miyamoto, Seiji; Nakamura, Yukiharu*; Nunes, I.*; Parail, V.*; Pereverzev, G. V.*; Peysson, Y.*; Polevoi, A.*; Politzer, P.*; Schneider, M.*; Sips, G.*; Tardini, G.*; Voitsekhovitch, I.*; Wolfe, S. M.*; Zhogolev, V. E.*; ASDEX Upgrade Team*; C-Mod Team*; DIII-D Team*; JET-EFDA Contributors*; JT-60U Team; Tore Supra Teams*; Contributors of the EU-ITM ITER Scenario Modelling Group*; ITPA "Integrated Operation Scenarios" Group*; ITPA "Transport and Confinement" Group*

ITERでの電流立ち上げ・立ち下げシナリオの準備に向けて、これら運転状態においてどの熱輸送モデルが適切であるかを決定するために、代表的なトカマクでの現在の実験結果を統合モデルシミュレーションにより解析した。本研究では、トカマク実験の解析結果をもとに、ITER標準誘導運転(プラズマ電流15MA)の電流立ち上げ・立ち下げシナリオでの予測を行った。統合モデルシミュレーション結果を、ASDEX Upgrade, C-Mod, DIII-D, JET, Tore Supraのオーミック加熱プラズマ及び外部加熱・電流駆動プラズマ実験データと比較することにより、さまざまな輸送モデルの検証を行った。最も実験結果の再現性の良かった幾つかのモデルを用いて、ITERの電流立ち上げ・立ち下げ段階での電子密度・電流密度プロファイルの予測を行った。電子温度プロファイルには輸送モデルによって大きな差が見られたが、最終的な電流密度プロファイルはモデル間でよく一致することがわかった。

In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from several tokamaks have been analyzed by means of integrated modeling in view of determining relevant heat transport models for these operation phases. The results of these studies are presented and projections to ITER current ramp-up and ramp-down scenarios are done, focusing on the baseline inductive scenario (main heating plateau current of 15 MA). Various transport models have been tested by means of integrated modeling against experimental data from ASDEX Upgrade, C-Mod, DIII-D, JET and Tore Supra, including both Ohmic plasmas and discharges with additional heating/current drive. With using the most successful models, projections to the ITER current ramp-up and ramp-down phases are carried out. Though significant differences between models appear on the electron temperature prediction, the final q-profiles reached in the simulation are rather close.