Noncircular Triangularity and Ellipticity-Induced Alfvén Eigenmodes Observed in JT-60U

G. J. Kramer; M. Saigusa; T. Ozeki; Y. Kusama; H. Kimura; T. Oikawa; K. Tobita; G. Y. Fu; C. Z. Cheng

doi:10.1103/PhysRevLett.80.2594

Noncircular Triangularity and Ellipticity-Induced Alfvén Eigenmodes Observed in JT-60U

G. J. Kramer, M. Saigusa, T. Ozeki, Y. Kusama, H. Kimura, T. Oikawa, K. Tobita, G. Y. Fu, and C. Z. Cheng

Phys. Rev. Lett. 80, 2594 – Published 23 March 1998

Abstract

For the first time noncircular triangularity induced Alfvén eigenmodes (NAE) were observed in combined ion cyclotron resonance frequency and neutral beam injection heated plasmas. Ellipticity induced Alfvén eigenmodes (EAE) and toroidicity-induced Alfvén eigenmodes (TAE) were also observed in those plasmas. The threshold beta of the energetic ions for exciting the NAE modes was found to be similar to that for exciting TAE modes.

Received 19 February 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.2594

Authors & Affiliations

G. J. Kramer¹, M. Saigusa¹, T. Ozeki¹, Y. Kusama¹, H. Kimura¹, T. Oikawa¹, K. Tobita¹, G. Y. Fu², and C. Z. Cheng²

¹Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka-machi, Naka-gun, Ibaraki-ken, Japan
²Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543