skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Spectral Effects on Fast Wave Core Heating and Current Drive

Abstract

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effectmore » (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations.« less

Authors:
Publication Date:
Research Org.:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
953212
Report Number(s):
PPPL-4406
TRN: US0902723
DOE Contract Number:  
DE-ACO2-09CH11466
Resource Type:
Conference
Journal Name:
Nuclear Fusion MS: NF/304788/PAP/12302
Additional Journal Information:
Conference: Twenty Second IAEA Fusion Energy Conference - 50th Anniversary of Controlled Nuclear Fusion Research, 13-18 October 2008, Geneva, Switzerland.
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANTENNAS; DEUTERIUM; EFFICIENCY; HARMONICS; HEATING; HELIUM; HYPOTHESIS; IAEA; LITHIUM; PLASMA; POWER LOSSES; STARK EFFECT; THERMONUCLEAR REACTORS; WAVE PROPAGATION; WAVELENGTHS; Heating, ICRF, Current Drive,RF Heating

Citation Formats

C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team. Spectral Effects on Fast Wave Core Heating and Current Drive. United States: N. p., 2009. Web.
C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team. Spectral Effects on Fast Wave Core Heating and Current Drive. United States.
C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team. Mon . "Spectral Effects on Fast Wave Core Heating and Current Drive". United States. https://www.osti.gov/servlets/purl/953212.
@article{osti_953212,
title = {Spectral Effects on Fast Wave Core Heating and Current Drive},
author = {C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team},
abstractNote = {Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations.},
doi = {},
journal = {Nuclear Fusion MS: NF/304788/PAP/12302},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {5}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: