Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment
Abstract
In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. Furthermore, the observations imply that nonlocal flux-drivenmore »
- Authors:
-
[1];
[1];
[3];
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- National Fusion Research Institute, Daejeon (South Korea)
- Univ. of California, Davis, CA (United States)
- Univ. of Wisconsin-Madison, Madison, WI (United States)
- Nova Photonics, Inc., Princeton, NJ (United States)
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1254752
- Alternate Identifier(s):
- OSTI ID: 1224930
- Report Number(s):
- PPPL-5196
Journal ID: ISSN 1070-664X; PHPAEN
- Grant/Contract Number:
- AC02-76CH03073; FG03-95ER54295; FG03-99ER54518
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 22; Journal Issue: 11; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; tokamaks; NSTX; transport phenomena; turbulence; turbulence measurement; RF heating; electronic transport; plasma turbulence; turbulent transport processes
Citation Formats
Ren, Y., Wang, W. X., LeBlanc, B. P., Guttenfelder, W., Kaye, S. M., Ethier, S., Mazzucato, E., Lee, K. C., Domier, C. W., Bell, R., Smith, D. R., and Yuh, H. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment. United States: N. p., 2015.
Web. doi:10.1063/1.4935113.
Ren, Y., Wang, W. X., LeBlanc, B. P., Guttenfelder, W., Kaye, S. M., Ethier, S., Mazzucato, E., Lee, K. C., Domier, C. W., Bell, R., Smith, D. R., & Yuh, H. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment. United States. https://doi.org/10.1063/1.4935113
Ren, Y., Wang, W. X., LeBlanc, B. P., Guttenfelder, W., Kaye, S. M., Ethier, S., Mazzucato, E., Lee, K. C., Domier, C. W., Bell, R., Smith, D. R., and Yuh, H. Tue .
"Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment". United States. https://doi.org/10.1063/1.4935113. https://www.osti.gov/servlets/purl/1254752.
@article{osti_1254752,
title = {Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment},
author = {Ren, Y. and Wang, W. X. and LeBlanc, B. P. and Guttenfelder, W. and Kaye, S. M. and Ethier, S. and Mazzucato, E. and Lee, K. C. and Domier, C. W. and Bell, R. and Smith, D. R. and Yuh, H.},
abstractNote = {In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. Furthermore, the observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.},
doi = {10.1063/1.4935113},
journal = {Physics of Plasmas},
number = 11,
volume = 22,
place = {United States},
year = {2015},
month = {11}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 9 works
Citation information provided by
Web of Science
Web of Science
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Prospects for pilot plants based on the tokamak, spherical tokamak and stellarator
journal, August 2011
- Menard, J. E.; Bromberg, L.; Brown, T.
- Nuclear Fusion, Vol. 51, Issue 10
Microinstability theory in tokamaks
journal, August 1978
- Tang, W. M.
- Nuclear Fusion, Vol. 18, Issue 8
Transient electron heat diffusivity obtained from trace impurity injection on TFTR
journal, March 1994
- Kissick, M. W.; Fredrickson, E. D.; Callen, J. D.
- Nuclear Fusion, Vol. 34, Issue 3
Strong Nonlocal Effects in a Tokamak Perturbative Transport Experiment
journal, May 1995
- Gentle, K. W.; Rowan, W. L.; Bravenec, R. V.
- Physical Review Letters, Vol. 74, Issue 18
Study of non-linear coupling of fluctuations at long distance in LHD
journal, November 2014
- Inagaki, S.; Tokuzawa, T.; Kobayashi, T.
- Nuclear Fusion, Vol. 54, Issue 11
Towards an emerging understanding of non-locality phenomena and non-local transport
journal, January 2015
- Ida, K.; Shi, Z.; Sun, H. J.
- Nuclear Fusion, Vol. 55, Issue 1
Confinement and local transport in the National Spherical Torus Experiment (NSTX)
journal, June 2007
- Kaye, S. M.; Levinton, F. M.; Stutman, D.
- Nuclear Fusion, Vol. 47, Issue 7
Electron Temperature Gradient Turbulence
journal, December 2000
- Dorland, W.; Jenko, F.; Kotschenreuther, M.
- Physical Review Letters, Vol. 85, Issue 26
Density Gradient Stabilization of Electron Temperature Gradient Driven Turbulence in a Spherical Tokamak
journal, April 2011
- Ren, Y.; Kaye, S. M.; Mazzucato, E.
- Physical Review Letters, Vol. 106, Issue 16
Resolving electron scale turbulence in spherical tokamaks with flow shear
journal, February 2011
- Guttenfelder, W.; Candy, J.
- Physics of Plasmas, Vol. 18, Issue 2
Exploration of spherical torus physics in the NSTX device
journal, March 2000
- Ono, M.; Kaye, S. M.; Peng, Y. -K. M.
- Nuclear Fusion, Vol. 40, Issue 3Y
A collective scattering system for measuring electron gyroscale fluctuations on the National Spherical Torus Experiment
journal, December 2008
- Smith, D. R.; Mazzucato, E.; Lee, W.
- Review of Scientific Instruments, Vol. 79, Issue 12
Localized measurement of turbulent fluctuations in tokamaks with coherent scattering of electromagnetic waves
journal, March 2003
- Mazzucato, E.
- Physics of Plasmas, Vol. 10, Issue 3
Operation of the NSTX Thomson scattering system
journal, March 2003
- LeBlanc, B. P.; Bell, R. E.; Johnson, D. W.
- Review of Scientific Instruments, Vol. 74, Issue 3
Confinement studies of auxiliary heated NSTX plasmas
journal, March 2004
- LeBlanc, B. P.; Bell, R. E.; Kaye, S. M.
- Nuclear Fusion, Vol. 44, Issue 4
Study of turbulent fluctuations driven by the electron temperature gradient in the National Spherical Torus Experiment
journal, April 2009
- Mazzucato, E.; Bell, R. E.; Ethier, S.
- Nuclear Fusion, Vol. 49, Issue 5
Experimental study of parametric dependence of electron-scale turbulence in a spherical tokamak
journal, May 2012
- Ren, Y.; Guttenfelder, W.; Kaye, S. M.
- Physics of Plasmas, Vol. 19, Issue 5
Electron-scale turbulence spectra and plasma thermal transport responding to continuous E × B shear ramp-up in a spherical tokamak
journal, July 2013
- Ren, Y.; Guttenfelder, W.; Kaye, S. M.
- Nuclear Fusion, Vol. 53, Issue 8
Carbon ion plume emission produced by charge exchange with neutral beams on National Spherical Torus Experiment
journal, October 2006
- Bell, Ronald E.
- Review of Scientific Instruments, Vol. 77, Issue 10
`Quasi-local' wave equations in toroidal geometry with applications to fast wave propagation and absorption at high harmonics of the ion cyclotron frequency
journal, October 2002
- Brambilla, Marco
- Plasma Physics and Controlled Fusion, Vol. 44, Issue 11
Comparison of initial value and eigenvalue codes for kinetic toroidal plasma instabilities
journal, August 1995
- Kotschenreuther, Mike; Rewoldt, G.; Tang, W. M.
- Computer Physics Communications, Vol. 88, Issue 2-3
Noncircular, finite aspect ratio, local equilibrium model
journal, April 1998
- Miller, R. L.; Chu, M. S.; Greene, J. M.
- Physics of Plasmas, Vol. 5, Issue 4
Anomalous Transport Scaling in the DIII-D Tokamak Matched by Supercomputer Simulation
journal, July 2003
- Candy, J.; Waltz, R. E.
- Physical Review Letters, Vol. 91, Issue 4
Nonlocal properties of gyrokinetic turbulence and the role of E×B flow shear
journal, July 2007
- Wang, W. X.; Hahm, T. S.; Lee, W. W.
- Physics of Plasmas, Vol. 14, Issue 7
Nonlinear flow generation by electrostatic turbulence in tokamaks
journal, July 2010
- Wang, W. X.; Diamond, P. H.; Hahm, T. S.
- Physics of Plasmas, Vol. 17, Issue 7
New Thermodynamical Force in Plasma Phase Space that Controls Turbulence and Turbulent Transport
journal, November 2012
- Itoh, Sanae-I.; Itoh, Kimitaka
- Scientific Reports, Vol. 2, Issue 1
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment
journal, May 2005
- Biewer, T. M.; Bell, R. E.; Diem, S. J.
- Physics of Plasmas, Vol. 12, Issue 5
Works referencing / citing this record:
Summary of magnetic fusion plasma physics in 1st AAPPS-DPP meeting
journal, March 2018
- Li, Jiangang; Zhong, Wulyu
- Reviews of Modern Plasma Physics, Vol. 2, Issue 1
Experimental study of quasi-coherent mode using EAST tangential CO 2 laser collective scattering diagnostic in far-forward mode
journal, January 2019
- Sun, P. J.; Li, Y. D.; Ren, Y.
- Physics of Plasmas, Vol. 26, Issue 1
Recent progress in understanding electron thermal transport in NSTX
journal, March 2017
- Ren, Y.; Belova, E.; Gorelenkov, N.
- Nuclear Fusion, Vol. 57, Issue 7
Experimental observation of electron-scale turbulence evolution across the L–H transition in the National Spherical Torus Experiment
journal, August 2019
- Ren, Y.; Smith, D. R.; Zweben, S. J.
- Nuclear Fusion, Vol. 59, Issue 9
Exploring the regime of validity of global gyrokinetic simulations with spherical tokamak plasmas
journal, December 2019
- Ren, Y.; Wang, W. X.; Guttenfelder, W.
- Nuclear Fusion, Vol. 60, Issue 2