First measurements of error fields on W7-X using flux surface mapping

Lazerson, Samuel A.; Otte, Matthias; Bozhenkov, Sergey; Biedermann, Christoph; Pedersen, Thomas Sunn

doi:10.1088/0029-5515/56/10/106005

First measurements of error fields on W7-X using flux surface mapping

Journal Article · Wed Aug 03 00:00:00 EDT 2016 · Nuclear Fusion

DOI:https://doi.org/10.1088/0029-5515/56/10/106005· OSTI ID:1335163

Lazerson, Samuel A. ^[1]; Otte, Matthias ^[2]; Bozhenkov, Sergey ^[2]; Biedermann, Christoph ^[2]; Pedersen, Thomas Sunn ^[2]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Max-Planck-Institut fur Plasmaphysik, Greifswald (Germany)

Error fields have been detected and quantified using the flux surface mapping diagnostic system on Wendelstein 7-X (W7-X). A low-field '$${\rlap{-}\ \iota} =1/2$$ ' magnetic configuration ($${\rlap{-}\ \iota} =\iota /2\pi $$ ), sensitive to error fields, was developed in order to detect their presence using the flux surface mapping diagnostic. In this configuration, a vacuum flux surface with rotational transform of n/m = 1/2 is created at the mid-radius of the vacuum flux surfaces. If no error fields are present a vanishingly small n/m = 5/10 island chain should be present. Modeling indicates that if an n = 1 perturbing field is applied by the trim coils, a large n/m = 1/2 island chain will be opened. This island chain is used to create a perturbation large enough to be imaged by the diagnostic. Phase and amplitude scans of the applied field allow the measurement of a small $$\sim 0.04$$ m intrinsic island chain with a $${{130}^{\circ}}$$ phase relative to the first module of the W7-X experiment. Lastly, these error fields are determined to be small and easily correctable by the trim coil system.

View Accepted Manuscript (DOE)

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)

Contributing Organization:: The W7-X Team

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1335163

Alternate ID(s):: OSTI ID: 1281330

Report Number(s):: 5233

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 10 Vol. 56; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (18)

Initial Vacuum Magnetic Field Mapping in the Compact Toroidal Hybrid Peterson, J. T.; Hartwell, G. J.; Knowlton, S. F. Journal of Fusion Energy, Vol. 26, Issue 1-2 https://doi.org/10.1007/s10894-006-9053-2	journal	December 2006
Improved sixth-order Runge-Kutta formulas and approximate continuous solution of ordinary differential equations Sarafyan, D. Journal of Mathematical Analysis and Applications, Vol. 40, Issue 2 https://doi.org/10.1016/0022-247X(72)90062-5	journal	November 1972
Analysis of the magnet support structure for the plasma fusion experiment Wendelstein 7-X Jaksic, Nikola; van Eeten, Paul; Bykov, Victor Computers & Structures, Vol. 89, Issue 11-12 https://doi.org/10.1016/j.compstruc.2010.10.017	journal	June 2011
Service oriented architecture for scientific analysis at W7-X. An example of a field line tracer Bozhenkov, S. A.; Geiger, J.; Grahl, M. Fusion Engineering and Design, Vol. 88, Issue 11 https://doi.org/10.1016/j.fusengdes.2013.07.003	journal	November 2013
Electron beam and magnetic field mapping techniques used to determine field errors in the ATF torsatron Colchin, R. J.; Anderson, F. S. B.; England, A. C. Review of Scientific Instruments, Vol. 60, Issue 8 https://doi.org/10.1063/1.1141082	journal	August 1989
Compact expressions for the Biot–Savart fields of a filamentary segment Hanson, James D.; Hirshman, Steven P. Physics of Plasmas, Vol. 9, Issue 10 https://doi.org/10.1063/1.1507589	journal	October 2002
Three-dimensional photogrammetric measurement of magnetic field lines in the WEGA stellarator Drewelow, Peter; Bräuer, Torsten; Otte, Matthias Review of Scientific Instruments, Vol. 80, Issue 12 https://doi.org/10.1063/1.3263820	journal	December 2009
The limits and challenges of error field correction for ITER Buttery, R. J.; Boozer, A. H.; Liu, Y. Q. Physics of Plasmas, Vol. 19, Issue 5 https://doi.org/10.1063/1.3694655	journal	May 2012
Chaotic coordinates for the Large Helical Device Hudson, S. R.; Suzuki, Y. Physics of Plasmas, Vol. 21, Issue 10 https://doi.org/10.1063/1.4897390	journal	October 2014
Error field correction in DIII-D Ohmic plasmas with either handedness Park, Jong-Kyu; Schaffer, Michael J.; La Haye, Robert J. Nuclear Fusion, Vol. 51, Issue 2 https://doi.org/10.1088/0029-5515/51/2/023003	journal	January 2011
Technical challenges in the construction of the steady-state stellarator Wendelstein 7-X Bosch, H. -S.; Wolf, R. C.; Andreeva, T. Nuclear Fusion, Vol. 53, Issue 12 https://doi.org/10.1088/0029-5515/53/12/126001	journal	November 2013
Physics in the magnetic configuration space of W7-X Geiger, J.; Beidler, C. D.; Feng, Y. Plasma Physics and Controlled Fusion, Vol. 57, Issue 1 https://doi.org/10.1088/0741-3335/57/1/014004	journal	November 2014
Setup and initial results from the magnetic flux surface diagnostics at Wendelstein 7-X Otte, M.; Aßmus, D.; Biedermann, C. Plasma Physics and Controlled Fusion, Vol. 58, Issue 6 https://doi.org/10.1088/0741-3335/58/6/064003	journal	May 2016
Physics of magnetically confined plasmas Boozer, Allen H. Reviews of Modern Physics, Vol. 76, Issue 4 https://doi.org/10.1103/RevModPhys.76.1071	journal	January 2005
The Trim Coils for the Wendelstein 7-X Magnet System Rummel, T.; Risse, K.; Kisslinger, J. IEEE Transactions on Applied Superconductivity, Vol. 22, Issue 3 https://doi.org/10.1109/TASC.2011.2182027	journal	June 2012
The Wendelstein 7-X Trim Coil System Rummel, Thomas; Neilson, Hutch; Risze, Konrad IEEE Transactions on Applied Superconductivity, Vol. 24, Issue 3 https://doi.org/10.1109/TASC.2013.2284671	journal	June 2014
Analysis of the Magnetic Field Perturbations during the Assembly of Wendelstein 7-X Andreeva, T.; Bräuer, T.; Endler, M. Fusion Science and Technology, Vol. 46, Issue 2 https://doi.org/10.13182/FST04-A578	journal	September 2004
Flux Surface Mapping in LHD Morisaki, T.; Shoji, M.; Masuzaki, S. Fusion Science and Technology, Vol. 58, Issue 1 https://doi.org/10.13182/FST10-A10832	journal	August 2010

Cited By (15)

Erratum: Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000 Pedersen, T. Sunn; Otte, M.; Lazerson, S. Nature Communications, Vol. 8, Issue 1 https://doi.org/10.1038/ncomms14491	journal	February 2017
Overdense microwave plasma heating in the CNT stellarator Hammond, K. C.; Diaz-Pacheco, R. R.; Koehn, A. arXiv https://doi.org/10.48550/arxiv.1708.02684	text	January 2017
HSX as an example of a resilient non-resonant divertor Bader, A.; Boozer, A. H.; Hegna, C. C. Physics of Plasmas, Vol. 24, Issue 3 https://doi.org/10.1063/1.4978494	journal	March 2017
Performance of Wendelstein 7-X stellarator plasmas during the first divertor operation phase Wolf, R. C.; Alonso, A.; Äkäslompolo, S. Physics of Plasmas, Vol. 26, Issue 8 https://doi.org/10.1063/1.5098761	journal	August 2019
Mapping of the HIDRA stellarator magnetic flux surfaces Rizkallah, Rabel; Marcinko, Steven; Curreli, Davide Physics of Plasmas, Vol. 26, Issue 9 https://doi.org/10.1063/1.5100744	journal	September 2019
Detection of an electron beam in a high density plasma via an electrostatic probe Majeski, Stephen; Yoo, Jongsoo; Zweben, Stewart Plasma Physics and Controlled Fusion, Vol. 60, Issue 7 https://doi.org/10.1088/1361-6587/aabd0e	journal	May 2018
Error fields in the Wendelstein 7-X stellarator Lazerson, Samuel A.; Bozhenkov, Sergey; Israeli, Ben Plasma Physics and Controlled Fusion, Vol. 60, Issue 12 https://doi.org/10.1088/1361-6587/aae96b	journal	November 2018
Large vacuum flux surfaces generated by tilted planar coils Li, Jessica L.; Austin, Jacob; Hammond, Kenneth C. Plasma Physics and Controlled Fusion, Vol. 61, Issue 7 https://doi.org/10.1088/1361-6587/ab1715	journal	May 2019
Major results from the first plasma campaign of the Wendelstein 7-X stellarator Wolf, R. C.; Ali, A.; Alonso, A. Nuclear Fusion, Vol. 57, Issue 10 https://doi.org/10.1088/1741-4326/aa770d	journal	July 2017
Final integration, commissioning and start of the Wendelstein 7-X stellarator operation Bosch, H. -S.; Brakel, R.; Braeuer, T. Nuclear Fusion, Vol. 57, Issue 11 https://doi.org/10.1088/1741-4326/aa7cbb	journal	August 2017
Application of Townsend avalanche theory to tokamak startup by coaxial helicity injection Hammond, K. C.; Raman, R.; Volpe, F. A. Nuclear Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/1741-4326/aa8fa4	journal	November 2017
Measurements and correction of the 1/1 error field in Wendelstein 7-X Bozhenkov, S. A.; Otte, M.; Biedermann, C. Nuclear Fusion, Vol. 59, Issue 2 https://doi.org/10.1088/1741-4326/aaf20c	journal	December 2018
Tuning of the rotational transform in Wendelstein 7-X Lazerson, Samuel A.; Gao, Yu; Hammond, Kenneth Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab3df0	journal	September 2019
Neural network regression approaches to reconstruct properties of magnetic configuration from Wendelstein 7-X modeled heat load patterns Blatzheim, Marko; Böckenhoff, Daniel Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab4123	journal	October 2019
Large vacuum flux surfaces generated by tilted planar coils Li, Jessica L.; Austin, Jacob; Israeli, Ben Y. arXiv https://doi.org/10.48550/arxiv.1809.10798	text	January 2018

Similar Records

Error field measurement, correction and heat flux balancing on Wendelstein 7-X

Journal Article · Thu Mar 09 19:00:00 EST 2017 · Nuclear Fusion · OSTI ID:1353402

Error field and magnetic diagnostic modeling for W7-X

Conference · Tue Jul 01 00:00:00 EDT 2014 · OSTI ID:1172621

Effect of error field correction coils on W7-X limiter loads

Journal Article · Tue Sep 26 20:00:00 EDT 2017 · Nuclear Fusion · OSTI ID:1466524

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
W7-X
error fields
flux surface mapping
stellarator

First measurements of error fields on W7-X using flux surface mapping

Citation Formats

References (18)

Cited By (15)

Similar Records

Related Subjects