Prediction of nonlinear evolution character of energetic-particle-driven instabilities

Author(s)

Duarte, V. N. ^{[1, 2]} ; Berk, H. L. ^[3] ; Gorelenkov, N. N. ^[2] ; Heidbrink, W. W. ^[4] ; Kramer, G. J. ^[2] ; Nazikian, R. ^[2] ; Pace, D. C. ^[5] ; Podesta, M. ^[2] ; Tobias, B. J. ^[2] ; Van Zeeland, M. A. ^[5]

Affiliation

^[1] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo, SP - Brazil

^[2] Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 - USA

^[3] Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 - USA

^[4] Univ Calif Irvine, Irvine, CA 92697 - USA

^[5] Gen Atom Co, San Diego, CA 92186 - USA

• Document type: Journal article
• Source: NUCLEAR FUSION; v. 57, n. 5 MAY 2017.
• Web of Science Citations: 20

Abstract

A general criterion is proposed and found to successfully predict the emergence of chirping oscillations of unstable Alfvenic eigenmodes in tokamak plasma experiments. The model includes realistic eigenfunction structure, detailed phase-space dependences of the instability drive, stochastic scattering and the Coulomb drag. The stochastic scattering combines the effects of collisional pitch angle scattering and micro-turbulence spatial diffusion. The latter mechanism is essential to accurately identify the transition between the fixed-frequency mode behavior and rapid chirping in tokamaks and to resolve the disparity with respect to chirping observation in spherical and conventional tokamaks. (AU)

• FAPESP's process: 14/03289-4 - Quasilinear theory of energetic particles interaction with toroidicity-induced Alfvén eigenmodes
• Grantee: Vinícius Njaim Duarte
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/22830-2 - Geodesic Acoustic Modes and Alfvén Continuum in Plasma Columns with Rotation
• Grantee: Vinícius Njaim Duarte
• Support Opportunities: Scholarships in Brazil - Doctorate