Experimental characterization of the effect of E×B shear on edge-harmonic oscillation mode structure
Abstract
The Edge Harmonic Oscillation (EHO) mode is one of the characteristic modes that provides an edge transport channel during high-confinement ELM-free phase (the so-called Quiescent High confinement phase). Recent theoretical work and extensive experimental observations have suggested that the large rotational E×B shear is the key to destabilize an EHO. As the eigenmode grows to large amplitude, it will exert a drag on the rotation, resulting in EHO's saturation. However, detailed mechanisms concerning this process remain vague. We have performed here continuous tracking on how the E×B shear affects the EHO mode structure to search for a possible explanation of the saturation mechanism. Two edge density fluctuation diagnostics are employed to observe the eigenmode structure evolution of EHO in the pedestal region in the radial and poloidal directions, respectively. Our results show that the EHO mode's radial wavenumber is strongly correlated with the E×B shear rate, while the poloidal wavenumber is unaffected by the E×B shear rate. During the EHO existence, with the E×B shearing rate ramping down, the radial wavenumber is also observed to be decreasing.
- Authors:
-
- Univ. of California, Davis, CA (United States)
- Univ. of California, Davis, CA (United States). Electrical and Computer Engineering
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- General Atomics, San Diego, CA (United States)
- General Atomics, San Diego, CA (United States); Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics
- General Atomics, San Diego, CA (United States). Engineering Physics
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States); Univ. of California, Davis, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- OSTI Identifier:
- 1512406
- Grant/Contract Number:
- AC02-09CH11466; FC02-04ER54698; SC0012551
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Plasma Physics and Controlled Fusion
- Additional Journal Information:
- Journal Volume: 61; Journal Issue: 8; Journal ID: ISSN 0741-3335
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 42 ENGINEERING
Citation Formats
Chen, Ming, Luo, Chen, Zhu, Yilun, Luhmann, Neville C., Tobias, B. J., Diallo, Ahmed, Kramer, Gerrit J., Ren, Yang, Burrell, Keith H., McKee, George R., and Yan, Zheng. Experimental characterization of the effect of E×B shear on edge-harmonic oscillation mode structure. United States: N. p., 2019.
Web. doi:10.1088/1361-6587/ab2174.
Chen, Ming, Luo, Chen, Zhu, Yilun, Luhmann, Neville C., Tobias, B. J., Diallo, Ahmed, Kramer, Gerrit J., Ren, Yang, Burrell, Keith H., McKee, George R., & Yan, Zheng. Experimental characterization of the effect of E×B shear on edge-harmonic oscillation mode structure. United States. https://doi.org/10.1088/1361-6587/ab2174
Chen, Ming, Luo, Chen, Zhu, Yilun, Luhmann, Neville C., Tobias, B. J., Diallo, Ahmed, Kramer, Gerrit J., Ren, Yang, Burrell, Keith H., McKee, George R., and Yan, Zheng. Mon .
"Experimental characterization of the effect of E×B shear on edge-harmonic oscillation mode structure". United States. https://doi.org/10.1088/1361-6587/ab2174. https://www.osti.gov/servlets/purl/1512406.
@article{osti_1512406,
title = {Experimental characterization of the effect of E×B shear on edge-harmonic oscillation mode structure},
author = {Chen, Ming and Luo, Chen and Zhu, Yilun and Luhmann, Neville C. and Tobias, B. J. and Diallo, Ahmed and Kramer, Gerrit J. and Ren, Yang and Burrell, Keith H. and McKee, George R. and Yan, Zheng},
abstractNote = {The Edge Harmonic Oscillation (EHO) mode is one of the characteristic modes that provides an edge transport channel during high-confinement ELM-free phase (the so-called Quiescent High confinement phase). Recent theoretical work and extensive experimental observations have suggested that the large rotational E×B shear is the key to destabilize an EHO. As the eigenmode grows to large amplitude, it will exert a drag on the rotation, resulting in EHO's saturation. However, detailed mechanisms concerning this process remain vague. We have performed here continuous tracking on how the E×B shear affects the EHO mode structure to search for a possible explanation of the saturation mechanism. Two edge density fluctuation diagnostics are employed to observe the eigenmode structure evolution of EHO in the pedestal region in the radial and poloidal directions, respectively. Our results show that the EHO mode's radial wavenumber is strongly correlated with the E×B shear rate, while the poloidal wavenumber is unaffected by the E×B shear rate. During the EHO existence, with the E×B shearing rate ramping down, the radial wavenumber is also observed to be decreasing.},
doi = {10.1088/1361-6587/ab2174},
journal = {Plasma Physics and Controlled Fusion},
number = 8,
volume = 61,
place = {United States},
year = {Mon May 13 00:00:00 EDT 2019},
month = {Mon May 13 00:00:00 EDT 2019}
}
Web of Science
Works referenced in this record:
The beam emission spectroscopy diagnostic on the DIII-D tokamak
journal, January 1999
- McKee, G.; Ashley, R.; Durst, R.
- Review of Scientific Instruments, Vol. 70, Issue 1
Integrated modeling applications for tokamak experiments with OMFIT
journal, July 2015
- Meneghini, O.; Smith, S. P.; Lao, L. L.
- Nuclear Fusion, Vol. 55, Issue 8
Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U
journal, July 2005
- Oyama, N.; Sakamoto, Y.; Isayama, A.
- Nuclear Fusion, Vol. 45, Issue 8
Role of edge electric field and poloidal rotation in the L - H transition
journal, June 1990
- Groebner, R. J.; Burrell, K. H.; Seraydarian, R. P.
- Physical Review Letters, Vol. 64, Issue 25
Quiescent H-Mode Plasmas with Strong Edge Rotation in the Cocurrent Direction
journal, April 2009
- Burrell, K. H.; Osborne, T. H.; Snyder, P. B.
- Physical Review Letters, Vol. 102, Issue 15
The EPED pedestal model and edge localized mode-suppressed regimes: Studies of quiescent H-mode and development of a model for edge localized mode suppression via resonant magnetic perturbations
journal, May 2012
- Snyder, P. B.; Osborne, T. H.; Burrell, K. H.
- Physics of Plasmas, Vol. 19, Issue 5
The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmasa)
journal, May 2015
- Garofalo, A. M.; Burrell, K. H.; Eldon, D.
- Physics of Plasmas, Vol. 22, Issue 5
Flow shear induced fluctuation suppression in finite aspect ratio shaped tokamak plasma
journal, May 1995
- Hahm, T. S.; Burrell, K. H.
- Physics of Plasmas, Vol. 2, Issue 5
Estimation of wavenumber and frequency spectra using fixed probe pairs
journal, June 1982
- Beall, J. M.; Kim, Y. C.; Powers, E. J.
- Journal of Applied Physics, Vol. 53, Issue 6
Improved edge charge exchange recombination spectroscopy in DIII-D
journal, August 2016
- Chrystal, C.; Burrell, K. H.; Grierson, B. A.
- Review of Scientific Instruments, Vol. 87, Issue 11
Edge pedestal control in quiescent H-mode discharges in DIII-D using co-plus counter-neutral beam injection
journal, July 2009
- Burrell, K. H.; Osborne, T. H.; Snyder, P. B.
- Nuclear Fusion, Vol. 49, Issue 8
Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation
journal, August 2007
- Snyder, P. B.; Burrell, K. H.; Wilson, H. R.
- Nuclear Fusion, Vol. 47, Issue 8
Quiescent Double Barrier Regime in the DIII-D Tokamak
journal, May 2001
- Greenfield, C. M.; Burrell, K. H.; DeBoo, J. C.
- Physical Review Letters, Vol. 86, Issue 20
EHO-like density fluctuations measured using beam emission spectroscopy in ETB discharges in CHS
journal, January 2006
- Oishi, T.; Kado, S.; Yoshinuma, M.
- Nuclear Fusion, Vol. 46, Issue 2
Studies of the ‘Quiescent H-mode’ regime in ASDEX Upgrade and JET
journal, July 2005
- Suttrop, W.; Hynönen, V.; Kurki-Suonio, T.
- Nuclear Fusion, Vol. 45, Issue 7
Synthetic diagnostic for electron cyclotron emission imaging
journal, October 2018
- Chen, M.; Zhu, Y.; Luo, C.
- Review of Scientific Instruments, Vol. 89, Issue 10
ELM-free stationary H-mode plasmas in the ASDEX Upgrade tokamak
journal, June 2003
- Suttrop, W.; Maraschek, M.; Conway, G. D.
- Plasma Physics and Controlled Fusion, Vol. 45, Issue 8
Advances towards QH-mode viability for ELM-stable operation in ITER
journal, July 2011
- Garofalo, A. M.; Solomon, W. M.; Park, J. -K.
- Nuclear Fusion, Vol. 51, Issue 8
Theory of plasma transport in toroidal confinement systems
journal, April 1976
- Hinton, F. L.; Hazeltine, R. D.
- Reviews of Modern Physics, Vol. 48, Issue 2
Synthetic diagnostics platform for fusion plasmas (invited)
journal, August 2016
- Shi, L.; Valeo, E. J.; Tobias, B. J.
- Review of Scientific Instruments, Vol. 87, Issue 11
Quiescent double barrier high-confinement mode plasmas in the DIII-D tokamak
journal, May 2001
- Burrell, K. H.; Austin, M. E.; Brennan, D. P.
- Physics of Plasmas, Vol. 8, Issue 5
Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D
journal, March 2016
- Burrell, K. H.; Barada, K.; Chen, X.
- Physics of Plasmas, Vol. 23, Issue 5
The Plasma Boundary of Magnetic Fusion Devices
book, January 2000
- Stangeby, P.
- Series in Plasma Physics
The Plasma Boundary of Magnetic Fusion Devices
journal, January 2001
- Ghendrih, Philippe
- Plasma Physics and Controlled Fusion, Vol. 43, Issue 2
Estimation of wavenumber and frequency spectra using fixed probe pairs
journal, June 1982
- Beall, J. M.; Kim, Y. C.; Powers, E. J.
- Journal of Applied Physics, Vol. 53, Issue 6