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Title: Fusion plasma theory: Task III, Auxiliary heating in tokamaks: Final report

Abstract

The research we have accomplished during the past three year period includes the topics of ICRF fast wave coupling to L- and H-mode edge profiles and coupled full wave ICRF field solutions for CIT and TFTR supershots. We have also developed Quasi-linear Fokker-Planck codes to model nonlocal wave reflection, mode conversion, wave deposition and simulation of core sawtooth phenomena for large tokamaks such as JET. We have also examined coupling between launched fast waves and ion Bernstein waves driven by density gradients near the plasma edge and the effects of known edge turbulence and ponderomotive effects on the direct launching of ion Bernstein waves. We find that a TE/sub 10/ ICRF fast mode waveguide launcher only has a moderate increase in its reflection coefficient when coupling into a model H-mode plasma density profile. Our full wave 1-D ICRF code results have corrected earlier formulations by other authors and described a method for calculation of wave fields with an evanescent ion Bernstein mode. The results show that wave reflections, minority and majority absorption and mode conversion are sensitive to plasma and wave parameters and yield stronger minority and majority than a WKB formulation would yield. We have coupled the wave heatingmore » code to a Fokker-Planck code to model strong electron sawtooth phenomena occurring during minority hydrogen heating on JET. We find that fast ion tail formation and electron drag heating rather than direct electron heating or electron heating via mode conversion to ion Bernstein waves play an important role in core plasma sawtooth dynamics. We find that linear coupling from fast modes to ion Bernstein modes occurs due to larger density gradient scale lengths near the plasma edge. 8 refs., 1 tab.« less

Authors:
Publication Date:
Research Org.:
Wisconsin Univ., Madison (USA). Dept. of Electrical and Computer Engineering
OSTI Identifier:
6932761
Report Number(s):
DOE/ER/53218-9
ON: DE89003256
DOE Contract Number:  
FG02-86ER53218
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TOKAMAK TYPE REACTORS; ICR HEATING; BERNSTEIN MODE; FINITE ELEMENT METHOD; FOKKER-PLANCK EQUATION; PROGRESS REPORT; WAVEGUIDES; DIFFERENTIAL EQUATIONS; DOCUMENT TYPES; EQUATIONS; HEATING; HIGH-FREQUENCY HEATING; NUMERICAL SOLUTION; OSCILLATION MODES; PARTIAL DIFFERENTIAL EQUATIONS; PLASMA HEATING; THERMONUCLEAR REACTORS; 700101* - Fusion Energy- Plasma Research- Confinement, Heating, & Production

Citation Formats

Scharer, J E. Fusion plasma theory: Task III, Auxiliary heating in tokamaks: Final report. United States: N. p., 1988. Web.
Scharer, J E. Fusion plasma theory: Task III, Auxiliary heating in tokamaks: Final report. United States.
Scharer, J E. Fri . "Fusion plasma theory: Task III, Auxiliary heating in tokamaks: Final report". United States.
@article{osti_6932761,
title = {Fusion plasma theory: Task III, Auxiliary heating in tokamaks: Final report},
author = {Scharer, J E},
abstractNote = {The research we have accomplished during the past three year period includes the topics of ICRF fast wave coupling to L- and H-mode edge profiles and coupled full wave ICRF field solutions for CIT and TFTR supershots. We have also developed Quasi-linear Fokker-Planck codes to model nonlocal wave reflection, mode conversion, wave deposition and simulation of core sawtooth phenomena for large tokamaks such as JET. We have also examined coupling between launched fast waves and ion Bernstein waves driven by density gradients near the plasma edge and the effects of known edge turbulence and ponderomotive effects on the direct launching of ion Bernstein waves. We find that a TE/sub 10/ ICRF fast mode waveguide launcher only has a moderate increase in its reflection coefficient when coupling into a model H-mode plasma density profile. Our full wave 1-D ICRF code results have corrected earlier formulations by other authors and described a method for calculation of wave fields with an evanescent ion Bernstein mode. The results show that wave reflections, minority and majority absorption and mode conversion are sensitive to plasma and wave parameters and yield stronger minority and majority than a WKB formulation would yield. We have coupled the wave heating code to a Fokker-Planck code to model strong electron sawtooth phenomena occurring during minority hydrogen heating on JET. We find that fast ion tail formation and electron drag heating rather than direct electron heating or electron heating via mode conversion to ion Bernstein waves play an important role in core plasma sawtooth dynamics. We find that linear coupling from fast modes to ion Bernstein modes occurs due to larger density gradient scale lengths near the plasma edge. 8 refs., 1 tab.},
doi = {},
url = {https://www.osti.gov/biblio/6932761}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1988},
month = {7}
}

Technical Report:
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