Validation of conducting wall models using magnetic measurements
Abstract
The impact of conducting wall eddy currents on perturbed magnetic field measurements is a key issue for understanding the measurement and control of long-wavelength MHD stability in tokamak devices. As plasma response models have growth in sophistication, the need to understand and resolve small changes in these measurements has become more important, motivating increased fidelity in simulations of externally applied fields and the wall eddy current response. In this manuscript, we describe thorough validation studies of the wall models in the MARS-F and VALEN stability codes, using coil–sensor vacuum coupling measurements from the DIII-D tokamak. The valen formulation treats conducting structures with arbitrary threedimensional geometries, while mars-f uses an axisymmetric wall model and a spectral decomposition of the problem geometry with a fixed toroidal harmonic n. The vacuum coupling measurements have a strong sensitivity to wall eddy currents induced by timechanging coil currents, owing to the close proximities of both the sensors and coils to the wall. Measurements from individual coil and sensor channels are directly compared with valen predictions. It is found that straightforward improvements to the valen model, such as refining the wall mesh and simulating the vertical extent of the DIII-D poloidal field sensors, lead to goodmore »
- Authors:
-
- Columbia Univ., New York, NY (United States)
- General Atomics, San Diego, CA (United States)
- Publication Date:
- Research Org.:
- Columbia Univ., New York, NY (United States); General Atomics, San Diego, CA (United States)
- Sponsoring Org.:
- USDOE Office of Nuclear Energy (NE)
- OSTI Identifier:
- 1354790
- Alternate Identifier(s):
- OSTI ID: 1295983
- Grant/Contract Number:
- FC02-04ER54698; FG02-95ER54309; FG02-04ER54761
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Fusion
- Additional Journal Information:
- Journal Volume: 56; Journal Issue: 10; Journal ID: ISSN 0029-5515
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; applied classical electromagnetism; electrostatics; magnetohydrodynamics; tokamaks; electric and magnetic measurements
Citation Formats
Hanson, Jeremy M., Bialek, James M., Turco, Francesca, King, J., Navratil, Gerald A., and Turnbull, Alan. Validation of conducting wall models using magnetic measurements. United States: N. p., 2016.
Web. doi:10.1088/0029-5515/56/10/106022.
Hanson, Jeremy M., Bialek, James M., Turco, Francesca, King, J., Navratil, Gerald A., & Turnbull, Alan. Validation of conducting wall models using magnetic measurements. United States. https://doi.org/10.1088/0029-5515/56/10/106022
Hanson, Jeremy M., Bialek, James M., Turco, Francesca, King, J., Navratil, Gerald A., and Turnbull, Alan. Tue .
"Validation of conducting wall models using magnetic measurements". United States. https://doi.org/10.1088/0029-5515/56/10/106022. https://www.osti.gov/servlets/purl/1354790.
@article{osti_1354790,
title = {Validation of conducting wall models using magnetic measurements},
author = {Hanson, Jeremy M. and Bialek, James M. and Turco, Francesca and King, J. and Navratil, Gerald A. and Turnbull, Alan},
abstractNote = {The impact of conducting wall eddy currents on perturbed magnetic field measurements is a key issue for understanding the measurement and control of long-wavelength MHD stability in tokamak devices. As plasma response models have growth in sophistication, the need to understand and resolve small changes in these measurements has become more important, motivating increased fidelity in simulations of externally applied fields and the wall eddy current response. In this manuscript, we describe thorough validation studies of the wall models in the MARS-F and VALEN stability codes, using coil–sensor vacuum coupling measurements from the DIII-D tokamak. The valen formulation treats conducting structures with arbitrary threedimensional geometries, while mars-f uses an axisymmetric wall model and a spectral decomposition of the problem geometry with a fixed toroidal harmonic n. The vacuum coupling measurements have a strong sensitivity to wall eddy currents induced by timechanging coil currents, owing to the close proximities of both the sensors and coils to the wall. Measurements from individual coil and sensor channels are directly compared with valen predictions. It is found that straightforward improvements to the valen model, such as refining the wall mesh and simulating the vertical extent of the DIII-D poloidal field sensors, lead to good agreement with the experimental measurements. In addition, couplings to multi-coil, n = 1 toroidal mode perturbations are calculated from the measurements and compared with predictions from both codes. Lastly, the toroidal mode comparisons favor the fully three-dimensional simulation approach, likely because this approach naturally treats n > 1 sidebands generated by the coils and wall eddy currents, as well as the n = 1 fundamental.},
doi = {10.1088/0029-5515/56/10/106022},
journal = {Nuclear Fusion},
number = 10,
volume = 56,
place = {United States},
year = {Tue Aug 16 00:00:00 EDT 2016},
month = {Tue Aug 16 00:00:00 EDT 2016}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 7 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:
Stabilization of kink instabilities by eddy currents in a segmented wall and comparison with ideal MHD theory
journal, July 1998
- Garofalo, A. M.; Eisner, E.; Ivers, T. H.
- Nuclear Fusion, Vol. 38, Issue 7
Vessel eddy current measurement for the National Spherical Torus Experiment
journal, December 2004
- Gates, D. A.; Menard, J. E.; Marsala, R. J.
- Review of Scientific Instruments, Vol. 75, Issue 12
Port hole perturbations to the magnetic field in MST
journal, July 2010
- Fimognari, P. J.; Almagri, A. F.; Anderson, J. K.
- Plasma Physics and Controlled Fusion, Vol. 52, Issue 9
Servo-control of plasma position in Cleo-Tokamak
journal, November 1974
- Hugill, J.; Gibson, A.
- Nuclear Fusion, Vol. 14, Issue 5
Feedback control of vertical plasma position in non-circular tokamak TNT-A
journal, October 1984
- Nagayama, Y.; Naito, M.; Ueda, Y.
- Nuclear Fusion, Vol. 24, Issue 10
Control of the vertical instability in tokamaks
journal, January 1990
- Lazarus, E. A.; Lister, J. B.; Neilson, G. H.
- Nuclear Fusion, Vol. 30, Issue 1
Mode locking in tokamaks
journal, December 1990
- Nave, M. F. F.; Wesson, J. A.
- Nuclear Fusion, Vol. 30, Issue 12
Interaction of tearing modes with external structures in cylindrical geometry (plasma)
journal, July 1993
- Fitzpatrick, R.
- Nuclear Fusion, Vol. 33, Issue 7
A theorem on MHD-instability of plasmas with resistive walls
journal, May 1971
- Pfirsch, D.; Tasso, H.
- Nuclear Fusion, Vol. 11, Issue 3
Error Field Amplification and Rotation Damping in Tokamak Plasmas
journal, May 2001
- Boozer, Allen H.
- Physical Review Letters, Vol. 86, Issue 22
Measurement of the Resistive-Wall-Mode Stability in a Rotating Plasma Using Active MHD Spectroscopy
journal, September 2004
- Reimerdes, H.; Chu, M. S.; Garofalo, A. M.
- Physical Review Letters, Vol. 93, Issue 13
Dynamics and control of resistive wall modes with magnetic feedback control coils: experiment and theory
journal, April 2005
- Mauel, M. E.; Bialek, J.; Boozer, A. H.
- Nuclear Fusion, Vol. 45, Issue 4
Investigation of resistive wall mode stabilization physics in high-beta plasmas using applied non-axisymmetric fields in NSTX
journal, August 2007
- Sontag, A. C.; Sabbagh, S. A.; Zhu, W.
- Nuclear Fusion, Vol. 47, Issue 8
Suppression of resistive wall instabilities with distributed, independently controlled, active feedback coils
journal, August 2000
- Cates, C.; Shilov, M.; Mauel, M. E.
- Physics of Plasmas, Vol. 7, Issue 8
Semiquantitative analysis of feedback systems for resistive wall modes
journal, November 2002
- Garofalo, A. M.; Jensen, T. H.; Strait, E. J.
- Physics of Plasmas, Vol. 9, Issue 11
Modeling of fast neutral-beam-generated ion effects on MHD-spectroscopic observations of resistive wall mode stability in DIII-D plasmas
journal, February 2015
- Turco, F.; Turnbull, A. D.; Hanson, J. M.
- Physics of Plasmas, Vol. 22, Issue 2
Evidence for the Importance of Trapped Particle Resonances for Resistive Wall Mode Stability in High Beta Tokamak Plasmas
journal, May 2011
- Reimerdes, H.; Berkery, J. W.; Lanctot, M. J.
- Physical Review Letters, Vol. 106, Issue 21
Feedback stabilization of nonaxisymmetric resistive wall modes in tokamaks. I. Electromagnetic model
journal, September 2000
- Liu, Y. Q.; Bondeson, A.; Fransson, C. M.
- Physics of Plasmas, Vol. 7, Issue 9
Validation of the linear ideal magnetohydrodynamic model of three-dimensional tokamak equilibria
journal, March 2010
- Lanctot, M. J.; Reimerdes, H.; Garofalo, A. M.
- Physics of Plasmas, Vol. 17, Issue 3
Experimental tests of linear and nonlinear three-dimensional equilibrium models in DIII-D
journal, July 2015
- King, J. D.; Strait, E. J.; Lazerson, S. A.
- Physics of Plasmas, Vol. 22, Issue 7
Three-Dimensional Drift Kinetic Response of High- Plasmas in the DIII-D Tokamak
journal, April 2015
- Wang, Z. R.; Lanctot, M. J.; Liu, Y. Q.
- Physical Review Letters, Vol. 114, Issue 14
Modeling of active control of external magnetohydrodynamic instabilities
journal, May 2001
- Bialek, James; Boozer, Allen H.; Mauel, M. E.
- Physics of Plasmas, Vol. 8, Issue 5
Coupling Between a 3-D Integral Eddy Current Formulation and a Linearized MHD Model for the Analysis of Resistive Wall Modes
journal, June 2008
- Albanese, R.; Liu, Y. Q.; Portone, A.
- IEEE Transactions on Magnetics, Vol. 44, Issue 6
Linearly perturbed MHD equilibria and 3D eddy current coupling via the control surface method
journal, May 2008
- Portone, A.; Villone, F.; Liu, Y.
- Plasma Physics and Controlled Fusion, Vol. 50, Issue 8
Resistive wall mode stabilization with internal feedback coils in DIII-D
journal, May 2004
- Strait, E. J.; Bialek, J. M.; Bogatu, I. N.
- Physics of Plasmas, Vol. 11, Issue 5
3D effects on RWM physics in RFX-mod
journal, July 2011
- Baruzzo, M.; Bolzonella, T.; Guo, S. C.
- Nuclear Fusion, Vol. 51, Issue 8
Dynamic simulator of RWM control for fusion devices: modelling and experimental validation on RFX-mod
journal, January 2012
- Marchiori, G.; Baruzzo, M.; Bolzonella, T.
- Nuclear Fusion, Vol. 52, Issue 2
A method for the estimate of the wall diffusion for non-axisymmetric fields using rotating external fields
journal, June 2013
- Frassinetti, L.; Olofsson, K. E. J.; Fridström, R.
- Plasma Physics and Controlled Fusion, Vol. 55, Issue 8
In situ “artificial plasma” calibration of tokamak magnetic sensors
journal, June 2013
- Shiraki, D.; Levesque, J. P.; Bialek, J.
- Review of Scientific Instruments, Vol. 84, Issue 6
Overview of physics results from the conclusive operation of the National Spherical Torus Experiment
journal, September 2013
- Sabbagh, S. A.; Ahn, J. -W.; Allain, J.
- Nuclear Fusion, Vol. 53, Issue 10
Magnetic diagnostic system of the DIII-D tokamak
journal, February 2006
- Strait, E. J.
- Review of Scientific Instruments, Vol. 77, Issue 2
An upgrade of the magnetic diagnostic system of the DIII-D tokamak for non-axisymmetric measurements
journal, August 2014
- King, J. D.; Strait, E. J.; Boivin, R. L.
- Review of Scientific Instruments, Vol. 85, Issue 8
Stabilization of external modes in tokamaks by resistive walls and plasma rotation
journal, April 1994
- Bondeson, A.; Ward, D. J.
- Physical Review Letters, Vol. 72, Issue 17
Overview of the DIII-D Fusion Science Program
journal, October 2005
- Luxon, J. L.; Simonen, T. C.; Stambaugh, R. D.
- Fusion Science and Technology, Vol. 48, Issue 2
Measurement of the electromagnetic torque in rotating DIII-D plasmas
journal, March 2010
- Logan, N. C.; Strait, E. J.; Reimerdes, H.
- Plasma Physics and Controlled Fusion, Vol. 52, Issue 4
Works referencing / citing this record:
$\mathscr{H}_2$ optimal control techniques for resistive wall mode feedback in tokamaks
journal, February 2018
- Clement, Mitchell; Hanson, Jeremy; Bialek, Jim
- Nuclear Fusion, Vol. 58, Issue 4
Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas
journal, January 2019
- Wang, Z. R.; Logan, N. C.; Munaretto, S.
- Nuclear Fusion, Vol. 59, Issue 2