Isotope effects on transport in LHD

Autor: Tsuyoshi Akiyama, Motoshi Goto, Tuomas Tala, Tokihiko Tokuzawa, Clive Michael, Hideaki Yamada, Haruhisa Nakano, Mamoru Shoji, Katsumi Ida, Toru Ii Tsujimura, Kenji Tanaka, Yasuo Yoshimura, Y. Ohtani, Sadayoshi Murakami, Suguru Masuzaki, Hiroto Takahashi, Felix Warmer, Shinsuke Satake, Y. Takemura, Hisamichi Funaba, Kiyofumi Mukai, L. N. Vacheslavov, Masaki Osakabe, Kenichi Nagaoka, Gen Motojima, Tomohiro Morisaki, Ryuichi Sakamoto, Motoki Nakata, Masayuki Yokoyama, S. Morita, Shin Kubo, Ryo Yasuhara, T. Kobayashi, Mikiro Yoshinuma, Toshiki Kinoshita, Ichihiro Yamada, Masanori Nunami, Hiroe Igami, Ryosuke Seki, T. Oishi, Takashi Shimozuma
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Plasma Physics and Controlled Fusion
Tanaka, K, Nagaoka, K, Ida, K, Yamada, H, Kobayashi, T, Satake, S, Nakata, M, Kinoshita, T, Ohtani, Y, Tokuzawa, T, Takahashi, H, Warmer, F, Mukai, K, Murakami, S, Sakamoto, R, Nakano, H, Osakabe, M, Morisaki, T, Nunami, M, Tala, T, Tsujimura, T, Takemura, Y, Yokoyama, M, Seki, R, Igami, H, Yoshimura, Y, Kubo, S, Shimozuma, T, Akiyama, T, Yamada, I, Yasuhara, R, Funaba, H, Yoshinuma, M, Goto, M, Oishi, T, Morita, S, Motojima, G, Shoji, M, Masuzaki, S, Michael, C A & Vacheslavov, L N 2021, ' Isotope effects on transport in LHD ', Plasma Physics and Controlled Fusion, vol. 63, no. 9, 094001 . https://doi.org/10.1088/1361-6587/abffb6
K Tanaka et al 2021 Plasma Phys. Control. Fusion 63 094001
Popis: Isotope effects are one of the most important issues for predicting future reactor operations. Large helical device (LHD) is the presently working largest stellarator/helical device using super conducting helical coils. In LHD, deuterium experiments started in 2017. Extensive studies regarding isotope effects on transport have been carried out. In this paper, the results of isotope effect studies in LHD are reported. The systematic studies were performed adjusting operational parameters and nondimensional parameters. In L mode like normal confinement plasma, where internal and edge transport barriers are not formed, the scaling of global energy confinement time (τ E) with operational parameters shows positive mass dependence (M 0.27; where M is effective ion mass) in electron cyclotron heating plasma and no mass dependence (M 0.0) in neutral beam injection heating plasma. The non-negative ion mass dependence is anti-gyro-Bohm scaling. The role of the turbulence in isotope effects was also found by turbulence measurements and gyrokinetic simulation. Better accessibility to electron and ion internal transport barrier (ITB) plasma is found in deuterium (D) plasma than in hydrogen (H). Gyro kinetic non-linear simulation shows reduced ion heat flux due to the larger generation of zonal flow in deuterium plasma. Peaked carbon density profile plays a prominent role in reducing ion energy transport in ITB plasma. This is evident only in plasma with deuterium ions. New findings on the mixing and non-mixing states of D and H particle transports are reported. In the mixing state, ion particle diffusivities are higher than electron particle diffusivities and D and H ion density profiles are almost identical. In the non-mixing state, ion particle diffusivity is much lower than electron diffusivity. Deuterium and hydrogen ion profiles are clearly different. Different turbulence structures were found in the mixing and non-mixing states suggesting different turbulence modes play a role.
Databáze: OpenAIRE