Transition of poloidal viscosity by electrode biasing in the Large Helical Device

S. Kitajima, H. Takahashi, K. Ishii, Y. Sato, M. Kanno, J. Tachibana, A. Okamoto, M. Sasao, S. Inagaki, M. Takayama, S. Masuzaki, M. Shoji, N. Ashikawa, M. Tokitani, M. Yokoyama, Y. Suzuki, S. Satake, T. Ido, A. Shimizu, C. SuzukiY. Nagayama, T. Tokuzawa, K. Nishimura, T. Morisaki

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Electrode biasing experiments were carried out in various magnetic configurations on the Large Helical Device (LHD). The transitions of poloidal viscosity, which were accompanied with bifurcation phenomena characterized by a negative resistance in an electrode characteristic, were clearly observed on LHD by the electrode biasing. The critical external driving force required for transition was compared with the local maximum in ion viscosity, and the radial resistivity before the transition also compared with the expected value from a neoclassical theory. The critical driving force increased and the radial resistivity decreased with the major radius of the magnetic axis Rax going outwards. The configuration dependence of the transition condition and the radial resistivity qualitatively agreed with neoclassical theories. The radial electric field and the viscosity were also evaluated by the neoclassical transport code for a non-axisymmetric system, and estimated electrode voltage required for the transition, which was consistent with the experimental results.

Original languageEnglish
Article number073014
JournalNuclear Fusion
Issue number7
Publication statusPublished - 2013 Jul


Dive into the research topics of 'Transition of poloidal viscosity by electrode biasing in the Large Helical Device'. Together they form a unique fingerprint.

Cite this