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Title: Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry

Abstract

Neoclassical transport of energetic minority tail ions, which are generated by high powered electromagnetic waves of the Ion Cyclotron Range of Frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail ion transport is investigated in the present work. The total tail ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail ion viscosity, driven by the localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to be usually small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate. 18 refs., 2 figs.

Authors:
 [1]; ;  [2]
  1. (New York Univ., NY (USA). Courant Inst. of Mathematical Sciences)
  2. (Princeton Univ., NJ (USA). Plasma Physics Lab.)
Publication Date:
Research Org.:
Princeton Univ., NJ (USA). Plasma Physics Lab.
Sponsoring Org.:
DOE/ER
OSTI Identifier:
5007006
Report Number(s):
PPPL-2662
ON: DE90005803; TRN: 90-004653
DOE Contract Number:
AC02-76CH03073
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ICR HEATING; NEOCLASSICAL TRANSPORT THEORY; TOKAMAK DEVICES; ANGULAR MOMENTUM; COULOMB SCATTERING; DISTRIBUTION FUNCTIONS; ENERGY TRANSPORT; KINETIC EQUATIONS; MAGNETIC FIELDS; BASIC INTERACTIONS; CLOSED PLASMA DEVICES; ELASTIC SCATTERING; ELECTROMAGNETIC INTERACTIONS; EQUATIONS; FUNCTIONS; HEATING; HIGH-FREQUENCY HEATING; INTERACTIONS; PLASMA HEATING; SCATTERING; THERMONUCLEAR DEVICES; TRANSPORT THEORY; 700101* - Fusion Energy- Plasma Research- Confinement, Heating, & Production; 700103 - Fusion Energy- Plasma Research- Kinetics

Citation Formats

Chang, C.S., Hammett, G.W., and Goldston, R.J.. Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry. United States: N. p., 1990. Web. doi:10.2172/5007006.
Chang, C.S., Hammett, G.W., & Goldston, R.J.. Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry. United States. doi:10.2172/5007006.
Chang, C.S., Hammett, G.W., and Goldston, R.J.. 1990. "Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry". United States. doi:10.2172/5007006. https://www.osti.gov/servlets/purl/5007006.
@article{osti_5007006,
title = {Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry},
author = {Chang, C.S. and Hammett, G.W. and Goldston, R.J.},
abstractNote = {Neoclassical transport of energetic minority tail ions, which are generated by high powered electromagnetic waves of the Ion Cyclotron Range of Frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail ion transport is investigated in the present work. The total tail ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail ion viscosity, driven by the localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to be usually small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate. 18 refs., 2 figs.},
doi = {10.2172/5007006},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1990,
month = 1
}

Technical Report:

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  • Neoclassical transport of energetic minority tail ions, which are generated by high-powered electromagnetic waves of the ion cyclotron range of frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail-ion transport is investigated in the present work. The total tail-ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail-ion viscosity, driven by themore » localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to usually be small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate.« less
  • The highly anisotropic particle distribution function of minority tail ions driven by ion-cyclotron resonance heating at the fundamental harmonic is calculated in a two-dimensional velocity space. It is assumed that the heating is strong enough to drive most of the resonant ions above the in-electron critical slowing-down energy. Simple analytic expressions for the tail distribution are obtained fro the case when the Doppler effect is sufficiently large to flatten the sharp pitch angle dependence in the bounce averaged qualilinear heating coefficient, D/sub b/, and for the case when D/sub b/ is assumed to be constant in pitch angle and energy.more » It is found that a simple constant-D/sub b/ solution can be used instead of the more complicated sharp-D/sub b/ solution for many analytic purposes. 4 refs., 4 figs.« less
  • The highly anisotropic particle distribution function of minority tail ions driven by ion-cyclotron resonance heating at the fundamental harmonic is calculated in a two-dimensional velocity space. It is assumed that the heating is strong enough to drive most of the resonant ions above the ion--electron critical slowing-down energy. Simple analytic expressions for the tail distribution are obtained for the cases when the bounce-averaged quasilinear heating coefficient {ital D}{sub {ital b}} is assumed to be constant in pitch angle and energy, when the Doppler effect is sufficiently large to flatten the sharp pitch angle dependence in {ital D}{sub {ital b}} butmore » the energy dependence is allowed, and when the sharp pitch angle dependence is retained. It is found that a simple constant-{ital D}{sub {ital b}} solution can be used instead of the more complicated velocity-dependent-{ital D}{sub {ital b}} solutions for many analytic purposes.« less
  • Radial particle and energy transport of the high-energy tail ions created by fundamental resonance heating of ion-cyclotron range of frequency waves is studied for tokamak and bumpy torus geometry. The lowest-order distribution function for the high-energy ions is calculated in a two-dimensional velocity space, and all the diffusion coefficients are explicitly evaluated.
  • Electron cyclotron wave absorption by mildly relativistic electrons in the low density regime of the PLT tokamak is investigated. Appreciable wave damping is found for vertical propagation at frequencies of 50, 60, and 70 GHz when the spatially constant cyclotron frequency is 89 GHz. The perpendicular temperature T/sub perpendicular/(v/sub parallel/) of the fast tail is also measured from emission of radiation in the same direction. The results obtained are in satisfactory agreement with the theory of wave emission and absorption.