UKAEA Papers

"Theory of Alfvén eigenmodes in shear reversed plasmas"

• B. N. Breizman
• H. L. Berk
• M. S. Pekker
• S. D. Pinches
• S. E. Sharapov

Plasma configurations with shear reversal are prone to the excitation of unusual Alfven eigenmodes by energetic particles. These modes exhibit a quasiperiodic pattern of predominantly upward frequency sweeping ( Alfven cascades ) as the safety factor q changes in time. This work presents a theory that employs two complementary mechanisms for establ…

"Alfvén wave cascades in a tokamak"

• S. E. Sharapov
• B. Alper
• H. L. Berk
• D. N. Borba
• B. N. Breizman
• et al.

Experiments designed for generating internal transport barriers in the plasmas of the Joint European Torus [JET, P. H. Rebut et al. , Proceedings of the 10th International Conference, Plasma Physics and Controlled Nuclear Fusion, London ~ International Atomic Energy Agency, Vienna, (1985), Vol. I, p. 11 ] reveal cascades of Alfven perturbations wit…

"Nonlinear magnetohydrodynamical effects in precessional fishbone oscillations"

• A. Ödblom
• B. N. Breizman
• S. E. Sharapov
• T. C. Hender
• V. P. Pastukhov

"Theoretical Interpretation of Alfvén Cascades in Tokamaks with Nonmonotonic q Profiles"

• H. L. Berk
• D. N. Borba
• B. N. Breizman
• S. D. Pinches
• S. E. Sharapov

Alfvén spectra in a reversed-shear tokamak plasma with a population of energetic ions exhibit a quasiperiodic pattern of primarily upward frequency sweeping (Alfvén cascade). Presented here is an explanation for such asymmetric sweeping behavior which involves finding a new energetic particle mode localized around the point of zero magnetic shear…