Quasilinear theory of electron transport by radio frequency waves and nonaxisymmetric perturbations in toroidal plasmas

Kominis, Y; Ram, AK; Hizanidis, K

dc.contributor.author	Kominis, Y	en
dc.contributor.author	Ram, AK	en
dc.contributor.author	Hizanidis, K	en
dc.date.accessioned	2014-03-01T01:29:04Z
dc.date.available	2014-03-01T01:29:04Z
dc.date.issued	2008	en
dc.identifier.issn	1070-664X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19110
dc.subject	electron transport theory	en
dc.subject	perturbation theory	en
dc.subject	plasma interactions	en
dc.subject	plasma magnetohydrodynamics	en
dc.subject	plasma radiofrequency heating	en
dc.subject	plasma toroidal confinement	en
dc.subject	plasma transport processes	en
dc.subject	tearing instability	en
dc.subject.classification	Physics, Fluids & Plasmas	en
dc.subject.other	Atoms	en
dc.subject.other	Cyclotrons	en
dc.subject.other	Diffusion	en
dc.subject.other	Equations of motion	en
dc.subject.other	Flow interactions	en
dc.subject.other	Fusion reactors	en
dc.subject.other	Magnetic fields	en
dc.subject.other	Magnetic flux	en
dc.subject.other	Magnetic materials	en
dc.subject.other	Magnetism	en
dc.subject.other	Mathematical operators	en
dc.subject.other	Orbits	en
dc.subject.other	Perturbation techniques	en
dc.subject.other	Phase equilibria	en
dc.subject.other	Phase space methods	en
dc.subject.other	Plasma diagnostics	en
dc.subject.other	Plasma simulation	en
dc.subject.other	Plasmas	en
dc.subject.other	Radio	en
dc.subject.other	Radio waves	en
dc.subject.other	Action variables	en
dc.subject.other	Angle variables	en
dc.subject.other	Axisymmetric	en
dc.subject.other	Chaotic orbits	en
dc.subject.other	Collision operators	en
dc.subject.other	Computational studies	en
dc.subject.other	Configuration spaces	en
dc.subject.other	Confined fusions	en
dc.subject.other	Corresponding relations	en
dc.subject.other	Current generations	en
dc.subject.other	Current profiles	en
dc.subject.other	Diffusion equations	en
dc.subject.other	Diffusion operators	en
dc.subject.other	Electron cyclotrons	en
dc.subject.other	Electron diffusions	en
dc.subject.other	Electron distributions	en
dc.subject.other	Electron dynamics	en
dc.subject.other	Electron motions	en
dc.subject.other	Electron transports	en
dc.subject.other	Field perturbations	en
dc.subject.other	Flux coordinates	en
dc.subject.other	Localized beams	en
dc.subject.other	Magnetic islands	en
dc.subject.other	Magnetic perturbations	en
dc.subject.other	Markovian	en
dc.subject.other	Momentum spaces	en
dc.subject.other	Neoclassical tearing modes	en
dc.subject.other	Nonresonant	en
dc.subject.other	Numerical codes	en
dc.subject.other	Phase spaces	en
dc.subject.other	Plasma currents	en
dc.subject.other	Plasma equilibriums	en
dc.subject.other	Quasilinear	en
dc.subject.other	Quasilinear diffusions	en
dc.subject.other	Quasilinear theories	en
dc.subject.other	Radial directions	en
dc.subject.other	Radio frequency waves	en
dc.subject.other	Regular orbits	en
dc.subject.other	Rf waves	en
dc.subject.other	Spatial diffusions	en
dc.subject.other	Spatial evolutions	en
dc.subject.other	Spatial profiles	en
dc.subject.other	Steady states	en
dc.subject.other	Time dependents	en
dc.subject.other	Toroidal plasmas	en
dc.subject.other	Electrons	en
dc.title	Quasilinear theory of electron transport by radio frequency waves and nonaxisymmetric perturbations in toroidal plasmas	en
heal.type	journalArticle	en
heal.identifier.primary	10.1063/1.3029736	en
heal.identifier.secondary	http://dx.doi.org/10.1063/1.3029736	en
heal.identifier.secondary	122501	en
heal.language	English	en
heal.publicationDate	2008	en
heal.abstract	The use of radio frequency waves to generate plasma current and to modify the current profile in magnetically confined fusion devices is well documented. The current is generated by the interaction of electrons with an appropriately tailored spectrum of externally launched rf waves. In theoretical and computational studies, the interaction of rf waves with electrons is represented by a quasilinear diffusion operator. The balance, in steady state, between the quasilinear operator and the collision operator gives the modified electron distribution from which the generated current can be calculated. In this paper the relativistic operator for momentum and spatial diffusion of electrons due to rf waves and nonaxisymmetric magnetic field perturbations is derived. Relativistic treatment is necessary for the interaction of electrons with waves in the electron cyclotron range of frequencies. The spatial profile of the rf waves is treated in general so that diffusion due to localized beams is included. The nonaxisymmetric magnetic field perturbations can be due to magnetic islands as in neoclassical tearing modes. The plasma equilibrium is expressed in terms of the magnetic flux coordinates of an axisymmetric toroidal plasma. The electron motion is described by guiding center coordinates using the action-angle variables of motion in an axisymmetric toroidal equilibrium. The Lie perturbation technique is used to derive a diffusion operator which is nonsingular and time dependent. The resulting action diffusion equation describes resonant and nonresonant momentum and spatial diffusion. Momentum space diffusion leads to current generation in the plasma and spatial diffusion describes the effect of rf waves and magnetic perturbations on spatial evolution of the current profile. Depending on the symmetry of the equilibrium and the corresponding relation of the action variables to the configuration space variables, in addition to diffusion along the radial direction, poloidal, and toroidal electron diffusion, is also described. In deriving the diffusion operator, no statistical assumption, such as, the Markovian assumption, for the underlying electron dynamics, is imposed. Consequently, the operator is time dependent and valid for a dynamical phase space that is a mix of correlated regular orbits and decorrelated chaotic orbits. The diffusion operator is expressed in a form suitable for implementation in a numerical code. © 2008 American Institute of Physics.	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Physics of Plasmas	en
dc.identifier.doi	10.1063/1.3029736	en
dc.identifier.isi	ISI:000262228500024	en
dc.identifier.volume	15	en
dc.identifier.issue	12	en