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Title: Response of multiscale turbulence to electron cyclotron heating in the DIII-D tokamak

Abstract

Small-scale density turbulence (k{sub perpendicular}{rho}{sub i}{approx}4-10) and electron thermal flux are both observed to increase during electron cyclotron heating (ECH) of a high-temperature tokamak plasma (k{sub perpendicular}) is the turbulent wavenumber and {rho}{sub i} the ion gyroradius). In contrast, large- (k{sub perpendicular}{rho}{sub i}{<=}1) and intermediate-scale (k{sub perpendicular}){rho}{sub i}{approx}1-3) turbulence n-tilde/n levels and ion thermal transport remain effectively constant. This implies that the small-scale turbulence is not a remnant or tail of the ubiquitous, large-scale or intermediate-scale turbulence, and also indicates a potentially important role in determining anomalous electron thermal transport. Radial scans of small-scale turbulence during ECH indicate decreased fluctuations in the deep core compared with increased levels towards the edge. This trend is consistent with linear gyrokinetic growth rate predictions for electron temperature gradient driven instabilities.

Authors:
; ; ; ; ;  [1]; ; ; ; ; ; ;  [2];  [3]
  1. University of California-Los Angeles, Los Angeles, California 90095 (United States)
  2. General Atomics, San Diego, California 92186 (United States)
  3. University of Texas-Austin, Austin, Texas 78712 (United States)
Publication Date:
OSTI Identifier:
20975055
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 5; Other Information: DOI: 10.1063/1.2714019; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOUNDARY LAYERS; DOUBLET-3 DEVICE; ECR HEATING; ELECTRON TEMPERATURE; ELECTRONS; FLUCTUATIONS; ION TEMPERATURE; IONS; PLASMA; PLASMA CONFINEMENT; PLASMA DENSITY; PLASMA INSTABILITY; RF SYSTEMS; TEMPERATURE GRADIENTS; TEMPERATURE RANGE 0400-1000 K; TURBULENCE

Citation Formats

Rhodes, T. L., Peebles, W. A., Nguyen, X. V., Doyle, E. J., Zeng, L., Wang, G., Van Zeeland, M. A., De Grassie, J. S., Burrell, K. H., DeBoo, J. C., Lohr, J., Petty, C. C., Greenfield, C. M., and Bravenec, R. V. Response of multiscale turbulence to electron cyclotron heating in the DIII-D tokamak. United States: N. p., 2007. Web. doi:10.1063/1.2714019.
Rhodes, T. L., Peebles, W. A., Nguyen, X. V., Doyle, E. J., Zeng, L., Wang, G., Van Zeeland, M. A., De Grassie, J. S., Burrell, K. H., DeBoo, J. C., Lohr, J., Petty, C. C., Greenfield, C. M., & Bravenec, R. V. Response of multiscale turbulence to electron cyclotron heating in the DIII-D tokamak. United States. doi:10.1063/1.2714019.
Rhodes, T. L., Peebles, W. A., Nguyen, X. V., Doyle, E. J., Zeng, L., Wang, G., Van Zeeland, M. A., De Grassie, J. S., Burrell, K. H., DeBoo, J. C., Lohr, J., Petty, C. C., Greenfield, C. M., and Bravenec, R. V. Tue . "Response of multiscale turbulence to electron cyclotron heating in the DIII-D tokamak". United States. doi:10.1063/1.2714019.
@article{osti_20975055,
title = {Response of multiscale turbulence to electron cyclotron heating in the DIII-D tokamak},
author = {Rhodes, T. L. and Peebles, W. A. and Nguyen, X. V. and Doyle, E. J. and Zeng, L. and Wang, G. and Van Zeeland, M. A. and De Grassie, J. S. and Burrell, K. H. and DeBoo, J. C. and Lohr, J. and Petty, C. C. and Greenfield, C. M. and Bravenec, R. V.},
abstractNote = {Small-scale density turbulence (k{sub perpendicular}{rho}{sub i}{approx}4-10) and electron thermal flux are both observed to increase during electron cyclotron heating (ECH) of a high-temperature tokamak plasma (k{sub perpendicular}) is the turbulent wavenumber and {rho}{sub i} the ion gyroradius). In contrast, large- (k{sub perpendicular}{rho}{sub i}{<=}1) and intermediate-scale (k{sub perpendicular}){rho}{sub i}{approx}1-3) turbulence n-tilde/n levels and ion thermal transport remain effectively constant. This implies that the small-scale turbulence is not a remnant or tail of the ubiquitous, large-scale or intermediate-scale turbulence, and also indicates a potentially important role in determining anomalous electron thermal transport. Radial scans of small-scale turbulence during ECH indicate decreased fluctuations in the deep core compared with increased levels towards the edge. This trend is consistent with linear gyrokinetic growth rate predictions for electron temperature gradient driven instabilities.},
doi = {10.1063/1.2714019},
journal = {Physics of Plasmas},
number = 5,
volume = 14,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}