Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak
Abstract
A profile for the critical gradient scale length (Lc) has been measured in L-mode discharges at the Alcator C-Mod tokamak, where electrons were heated by an ion cyclotron range of frequency through minority heating with the intention of simultaneously varying the heat flux and changing the local gradient. The electron temperature gradient scale length (LTe-1= |∇Te|/Te) profile was measured via the BT-jog technique and it was compared with electron heat flux from power balance (TRANSP) analysis. The Te profiles were found to be very stiff and already above the critical values, however, the stiffness was found to be reduced near the q = 3/2 surface. The measured Lc profile is in agreement with electron temperature gradient (ETG) models which predict the dependence of Lc-1 on local ,Zeff, Te/Ti, and the ratio of the magnetic shear to the safety factor. The results from linear Gene gyrokinetic simulations suggest ETG to be the dominant mode of turbulence in the electron scale (k⊥ρs > 1), and ion temperature gradient/trapped electron mode modes in the ion scale (k⊥ρs > 1). Finally, the measured Lc profile is in agreement with the profile of ETG critical gradients deduced from GENE simulations.
- Authors:
-
[1];
[1];
[1];
[2];
[2];
- Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
- Publication Date:
- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Univ. of Texas, Austin, TX (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1540168
- Alternate Identifier(s):
- OSTI ID: 1432578
- Grant/Contract Number:
- FC02-99ER54512; FG03-96ER54373
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 25; Journal Issue: 4; 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; physics
Citation Formats
Houshmandyar, S., Hatch, D. R., Horton, C. W., Liao, K. T., Phillips, P. E., Rowan, W. L., Zhao, B., Cao, N. M., Ernst, D. R., Greenwald, M., Howard, N. T., Hubbard, A. E., Hughes, J. W., and Rice, J. E. Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak. United States: N. p., 2018.
Web. doi:10.1063/1.5022180.
Houshmandyar, S., Hatch, D. R., Horton, C. W., Liao, K. T., Phillips, P. E., Rowan, W. L., Zhao, B., Cao, N. M., Ernst, D. R., Greenwald, M., Howard, N. T., Hubbard, A. E., Hughes, J. W., & Rice, J. E. Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak. United States. https://doi.org/10.1063/1.5022180
Houshmandyar, S., Hatch, D. R., Horton, C. W., Liao, K. T., Phillips, P. E., Rowan, W. L., Zhao, B., Cao, N. M., Ernst, D. R., Greenwald, M., Howard, N. T., Hubbard, A. E., Hughes, J. W., and Rice, J. E. Tue .
"Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak". United States. https://doi.org/10.1063/1.5022180. https://www.osti.gov/servlets/purl/1540168.
@article{osti_1540168,
title = {Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak},
author = {Houshmandyar, S. and Hatch, D. R. and Horton, C. W. and Liao, K. T. and Phillips, P. E. and Rowan, W. L. and Zhao, B. and Cao, N. M. and Ernst, D. R. and Greenwald, M. and Howard, N. T. and Hubbard, A. E. and Hughes, J. W. and Rice, J. E.},
abstractNote = {A profile for the critical gradient scale length (Lc) has been measured in L-mode discharges at the Alcator C-Mod tokamak, where electrons were heated by an ion cyclotron range of frequency through minority heating with the intention of simultaneously varying the heat flux and changing the local gradient. The electron temperature gradient scale length (LTe-1= |∇Te|/Te) profile was measured via the BT-jog technique and it was compared with electron heat flux from power balance (TRANSP) analysis. The Te profiles were found to be very stiff and already above the critical values, however, the stiffness was found to be reduced near the q = 3/2 surface. The measured Lc profile is in agreement with electron temperature gradient (ETG) models which predict the dependence of Lc-1 on local ,Zeff, Te/Ti, and the ratio of the magnetic shear to the safety factor. The results from linear Gene gyrokinetic simulations suggest ETG to be the dominant mode of turbulence in the electron scale (k⊥ρs > 1), and ion temperature gradient/trapped electron mode modes in the ion scale (k⊥ρs > 1). Finally, the measured Lc profile is in agreement with the profile of ETG critical gradients deduced from GENE simulations.},
doi = {10.1063/1.5022180},
journal = {Physics of Plasmas},
number = 4,
volume = 25,
place = {United States},
year = {Tue Apr 10 00:00:00 EDT 2018},
month = {Tue Apr 10 00:00:00 EDT 2018}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 3 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:
Energy transport during off-axis neutral beam heating in the DIII-D tokamak
journal, March 1998
- Gohil, P.; Burrell, K. H.; Osborne, T. H.
- Nuclear Fusion, Vol. 38, Issue 3
Chapter 10: Core Transport Studies in JET
journal, May 2008
- Mantica, P.; Corrigan, G.; Garbet, X.
- Fusion Science and Technology, Vol. 53, Issue 4
Properties of ion temperature gradient drift instabilities in H ‐mode plasmas
journal, June 1989
- Hahm, T. S.; Tang, W. M.
- Physics of Fluids B: Plasma Physics, Vol. 1, Issue 6
Experimental Study of the Ion Critical-Gradient Length and Stiffness Level and the Impact of Rotation in the JET Tokamak
journal, April 2009
- Mantica, P.; Strintzi, D.; Tala, T.
- Physical Review Letters, Vol. 102, Issue 17
Inward transport of energy during off-axis heating on the DIII-D tokamak
journal, January 1994
- Petty, C. C.; Luce, T. C.
- Nuclear Fusion, Vol. 34, Issue 1
Benchmarking the GENE and GYRO codes through the relative roles of electromagnetic and E × B stabilization in JET high-performance discharges
journal, November 2016
- Bravenec, R.; Citrin, J.; Candy, J.
- Plasma Physics and Controlled Fusion, Vol. 58, Issue 12
Observation of a Critical Gradient Threshold for Electron Temperature Fluctuations in the DIII-D Tokamak
journal, January 2013
- Hillesheim, J. C.; DeBoo, J. C.; Peebles, W. A.
- Physical Review Letters, Vol. 110, Issue 4
20 years of research on the Alcator C-Mod tokamaka)
journal, November 2014
- Greenwald, M.; Bader, A.; Baek, S.
- Physics of Plasmas, Vol. 21, Issue 11
Experimental characterization of multiscale and multifield turbulence as a critical gradient threshold is surpassed in the DIII-D tokamak
journal, May 2013
- Hillesheim, J. C.; DeBoo, J. C.; Peebles, W. A.
- Physics of Plasmas, Vol. 20, Issue 5
Prediction of Significant Tokamak Turbulence at Electron Gyroradius Scales
journal, November 2002
- Jenko, F.; Dorland, W.
- Physical Review Letters, Vol. 89, Issue 22
Thomson scattering upgrades on Alcator C-Mod
journal, March 2003
- Hughes, J. W.; Mossessian, D.; Zhurovich, K.
- Review of Scientific Instruments, Vol. 74, Issue 3
Characterizing electron temperature gradient turbulence via numerical simulation
journal, December 2006
- Nevins, W. M.; Candy, J.; Cowley, S.
- Physics of Plasmas, Vol. 13, Issue 12
Discriminating the role of rotation and its gradient in determining ion stiffness mitigation in JET
journal, January 2013
- Baiocchi, B.; Mantica, P.; Giroud, C.
- Plasma Physics and Controlled Fusion, Vol. 55, Issue 2
Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration
journal, July 2016
- Houshmandyar, S.; Yang, Z. J.; Phillips, P. E.
- Review of Scientific Instruments, Vol. 87, Issue 11
Perturbative studies of turbulent transport in fusion plasmas
journal, July 2006
- Mantica, Paola; Ryter, François
- Comptes Rendus Physique, Vol. 7, Issue 6
Electron temperature gradient driven turbulence
journal, May 2000
- Jenko, F.; Dorland, W.; Kotschenreuther, M.
- Physics of Plasmas, Vol. 7, Issue 5
Experimental Study of Trapped-Electron-Mode Properties in Tokamaks: Threshold and Stabilization by Collisions
journal, August 2005
- Ryter, F.; Angioni, C.; Peeters, A. G.
- Physical Review Letters, Vol. 95, Issue 8
A Key to Improved Ion Core Confinement in the JET Tokamak: Ion Stiffness Mitigation due to Combined Plasma Rotation and Low Magnetic Shear
journal, September 2011
- Mantica, P.; Angioni, C.; Challis, C.
- Physical Review Letters, Vol. 107, Issue 13
Critical gradient formula for toroidal electron temperature gradient modes
journal, September 2001
- Jenko, F.; Dorland, W.; Hammett, G. W.
- Physics of Plasmas, Vol. 8, Issue 9
Identification of plasma-edge-related operational regime boundaries and the effect of edge instability on confinement in ASDEX Upgrade
journal, December 1997
- Suttrop, W.; Kaufmann, M.; Blank, H. J. de
- Plasma Physics and Controlled Fusion, Vol. 39, Issue 12
Electron transport in Tore Supra with fast wave electron heating
journal, May 2000
- Horton, W.; Zhu, P.; Hoang, G. T.
- Physics of Plasmas, Vol. 7, Issue 5
Multi-scale gyrokinetic simulations: Comparison with experiment and implications for predicting turbulence and transport
journal, April 2016
- Howard, N. T.; Holland, C.; White, A. E.
- Physics of Plasmas, Vol. 23, Issue 5
Toroidal kinetic η i ‐mode study in high‐temperature plasmas
journal, March 1992
- Dong, J. Q.; Horton, W.; Kim, J. Y.
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 7
Electron heat transport studies
journal, November 2006
- Ryter, F.; Camenen, Y.; DeBoo, J. C.
- Plasma Physics and Controlled Fusion, Vol. 48, Issue 12B
High resolution electron cyclotron emission temperature profile and fluctuation diagnostic for Alcator C-Mod
journal, January 1999
- Heard, J. W.; Watts, C.; Gandy, R. F.
- Review of Scientific Instruments, Vol. 70, Issue 1
Experimental Determination of Critical Threshold in Electron Transport on Tore Supra
journal, September 2001
- Hoang, G. T.; Bourdelle, C.; Garbet, X.
- Physical Review Letters, Vol. 87, Issue 12
Electron Temperature Gradient Turbulence
journal, December 2000
- Dorland, W.; Jenko, F.; Kotschenreuther, M.
- Physical Review Letters, Vol. 85, Issue 26
Nonlinear Stabilization of Tokamak Microturbulence by Fast Ions
journal, October 2013
- Citrin, J.; Jenko, F.; Mantica, P.
- Physical Review Letters, Vol. 111, Issue 15
High resolution ECE radiometer for electron temperature profile and fluctuation measurements on Alcator C-Mod
journal, January 2001
- Chatterjee, R.; Phillips, P. E.; Heard, J.
- Fusion Engineering and Design, Vol. 53, Issue 1-4
ITER predictions using the GYRO verified and experimentally validated trapped gyro-Landau fluid transport model
journal, June 2011
- Kinsey, J. E.; Staebler, G. M.; Candy, J.
- Nuclear Fusion, Vol. 51, Issue 8
Spatially resolved high resolution x-ray spectroscopy for magnetically confined fusion plasmas (invited)
journal, October 2008
- Ince-Cushman, A.; Rice, J. E.; Bitter, M.
- Review of Scientific Instruments, Vol. 79, Issue 10, Article No. 10E302
Drift waves and transport
journal, April 1999
- Horton, W.
- Reviews of Modern Physics, Vol. 71, Issue 3
Ion temperature‐gradient‐driven modes and anomalous ion transport in tokamaks
journal, May 1989
- Romanelli, F.
- Physics of Fluids B: Plasma Physics, Vol. 1, Issue 5
Electron heat transport in improved confinement discharges in DIII-D
journal, May 1999
- Stallard, B. W.; Greenfield, C. M.; Staebler, G. M.
- Physics of Plasmas, Vol. 6, Issue 5
H mode confinement in Alcator C-Mod
journal, June 1997
- Greenwald, M.; Boivin, R. L.; Bombarda, F.
- Nuclear Fusion, Vol. 37, Issue 6
Electron transport and the critical temperature gradient
journal, May 2004
- Horton, W.; Hoang, G. T.; Bourdelle, C.
- Physics of Plasmas, Vol. 11, Issue 5
Ion temperature profile stiffness: non-linear gyrokinetic simulations and comparison with experiment
journal, February 2014
- Citrin, J.; Jenko, F.; Mantica, P.
- Nuclear Fusion, Vol. 54, Issue 2
Electron profile stiffness and critical gradient studies
journal, August 2012
- DeBoo, J. C.; Petty, C. C.; White, A. E.
- Physics of Plasmas, Vol. 19, Issue 8
Confinement and Transport Research in Alcator C-Mod
journal, April 2007
- Greenwald, M.; Basse, N.; Bonoli, P.
- Fusion Science and Technology, Vol. 51, Issue 3
Ion temperature profile stiffness: non-linear gyrokinetic simulations and comparison with experiment
text, January 2013
- Citrin, J.; Jenko, F.; Mantica, P.
- arXiv
Works referencing / citing this record:
Variable location channels to improve efficiency and precision for direct ∇ T e measurements and high spatial resolution T e -profile measurements using electron cyclotron emission
journal, October 2018
- Houshmandyar, S.; Austin, M. E.; Brookman, M. W.
- Review of Scientific Instruments, Vol. 89, Issue 10
Helical core formation and evolution during current ramp-up in the high-field tokamak Alcator C-Mod
journal, February 2019
- Wingen, A.; Wilcox, R. S.; Delgado-Aparicio, L. F.
- Physics of Plasmas, Vol. 26, Issue 2