Theoretical Interpretation of Alfvén Cascades in Tokamaks with Nonmonotonic <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">q</mi></math></span> Profiles

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

doi:10.1103/PhysRevLett.87.185002

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

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

Phys. Rev. Lett. 87, 185002 – Published 15 October 2001

Abstract

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.

Received 18 June 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.185002

Authors & Affiliations

H. L. Berk¹, D. N. Borba^2,3, B. N. Breizman¹, S. D. Pinches⁴, and S. E. Sharapov⁵

¹Institute for Fusion Studies, The University of Texas, Austin, Texas 78712
²Associacao EURATOM/IST, Avenue Rovisto Pais, 1049-001 Lisboa, Portugal
³EFDA Close Support Unit, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
⁴Max-Planck Institut fur Plasmaphysik, EURATOM Association, Garching D-85748, Germany
⁵EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom