Effects of toroidal field ripple on suprathermal ions in tokamak plasmas

Robert James Goldston, H. H. Towner

Research output: Contribution to journalArticle

66 Scopus citations

Abstract

Analytic calculations of three important effects of toroidal field ripple on suprathermal ions in tokamak plasmas are presented. In the first process, collisional ripple-trapping, ions become trapped in local magnetic wells near their banana tips owing to pitch-angle scattering as they traverse the ripple on barely unripple-trapped orbits. In the second process, collisionless ripple-trapping, ions are captured (again near a banana tip) owing to their finite orbits, which carry them out into regions of higher ripple. In the third process, banana-drift diffusion, fast-ion banana orbits fail to close precisely, due to a ripple-induced ‘e lingering period ’e banana tips. These three mechanisms lead to substantial radial transport of banana-trapped, neutral-beam-injected ions when the quantity a*n O/Nqsis of order unity or smaller.

Original languageEnglish (US)
Pages (from-to)283-307
Number of pages25
JournalJournal of Plasma Physics
Volume26
Issue number2
DOIs
StatePublished - Jan 1 1981

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

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