Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations
Abstract
Here, three dimensional (3D) divertor particle flux footprints induced by the lower hybrid wave (LHW) have been systematically investigated in the EAST superconducting tokamak during the recent experimental campaign. We find that the striated particle flux (SPF) peaks away from the strike point (SP) closely fit the pitch of the edge magnetic field line for different safety factors q 95, as predicted by a field line tracing code taking into account the helical current filaments (HCFs) in the scrape-off-layer (SOL). As LHW power increases, it requires the fuelling to be increased e.g. by super molecular beam injection (SMBI), to maintain a similar plasma density, which may be attributed to the pump-out effect due to LHW, and may thus be beneficial for EAST steady state operations. The 3D SPF structure is observed with a LHW power threshold (P LHW ~ 0.9 MW). The ratio of the particle fluxes between SPF and outer strike point (OSP), i.e. $${{\Gamma }_{{\rm ion},{\rm SPF}}}/{{\Gamma }_{{\rm ion},{\rm OSP}}}$$ , increases with the LHW power. Upon transition to divertor detachment, the particle flux at the main OSP decreases, as expected, however, the particle flux at SPF continues increasing, in contrast to the RMP-induced striations that vanish with increasing divertor density. In addition, we also find that the in–out asymmetry of the 3D particle flux footprint pattern exhibits a clear dependence on the toroidal field direction (B × ∇ B ↓ and B × ∇ B↑). Experiments using neon impurity seeding show a promising capability in 3D particle and heat flux control on EAST. LHW-induced particle and heat flux striations are also present in the H-mode plasmas, reducing the peak heat flux and erosion at the main strike point, thus facilitating long-pulse operation with a new steady-state H-mode over 60s being recently achieved in EAST.
- Authors:
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[3];
[6];
[1];
more »
- Chinese Academy of Sciences, Hefei (People's Republic of China); Univ. of Science and Technology of China, Hefei (People's Republic of China)
- Chinese Academy of Sciences, Hefei (People's Republic of China); Dalian Univ. of Technology, Dalian (People's Republic of China)
- Forschungszentrum Julich GmbH, Julich (Germany)
- Chinese Academy of Sciences, Hefei (People's Republic of China); Forschungszentrum Julich GmbH, Julich (Germany)
- Chinese Academy of Sciences, Hefei (People's Republic of China); General Atomics, San Diego, CA (United States)
- Chinese Academy of Sciences, Hefei (People's Republic of China)
- CEA, IRFM, Saint-Paul-lez-Durance (France)
- Dalian Univ. of Technology, Dalian (People's Republic of China)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- General Atomics, San Diego, CA (United States)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- Contributing Org.:
- The EAST team
- OSTI Identifier:
- 1471878
- Grant/Contract Number:
- AC05-00OR22725
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Fusion
- Additional Journal Information:
- Journal Volume: 57; Journal Issue: 12; Journal ID: ISSN 0029-5515
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 3D effect; particle flux footprint; lower hybrid wave; helical current filaments
Citation Formats
Feng, W., Wang, L., Rack, M., Liang, Y., Guo, H. Y., Xu, G. S., Xu, J. C., Liu, J. B., Sun, Y. W., Jia, M. N., Yang, Q. Q., Zhang, B., Zou, X. L., Liu, H., Zhang, T., Ding, F., Chen, J. B., Duan, Y. M., Zheng, X. W., Dai, S. Y., Deng, G. Z., Chen, R., Hu, G. H., Yan, N., Si, H., Liu, S. C., Xu, S., Wang, M., Li, M. H., Ding, B. J., Wingen, Andreas, Huang, J., Gao, X., Luo, G. N., Gong, X. Z., Garofalo, A. M., Li, J., and Wan, B. N. Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations. United States: N. p., 2017.
Web. doi:10.1088/1741-4326/aa8bf3.
Feng, W., Wang, L., Rack, M., Liang, Y., Guo, H. Y., Xu, G. S., Xu, J. C., Liu, J. B., Sun, Y. W., Jia, M. N., Yang, Q. Q., Zhang, B., Zou, X. L., Liu, H., Zhang, T., Ding, F., Chen, J. B., Duan, Y. M., Zheng, X. W., Dai, S. Y., Deng, G. Z., Chen, R., Hu, G. H., Yan, N., Si, H., Liu, S. C., Xu, S., Wang, M., Li, M. H., Ding, B. J., Wingen, Andreas, Huang, J., Gao, X., Luo, G. N., Gong, X. Z., Garofalo, A. M., Li, J., & Wan, B. N. Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations. United States. https://doi.org/10.1088/1741-4326/aa8bf3
Feng, W., Wang, L., Rack, M., Liang, Y., Guo, H. Y., Xu, G. S., Xu, J. C., Liu, J. B., Sun, Y. W., Jia, M. N., Yang, Q. Q., Zhang, B., Zou, X. L., Liu, H., Zhang, T., Ding, F., Chen, J. B., Duan, Y. M., Zheng, X. W., Dai, S. Y., Deng, G. Z., Chen, R., Hu, G. H., Yan, N., Si, H., Liu, S. C., Xu, S., Wang, M., Li, M. H., Ding, B. J., Wingen, Andreas, Huang, J., Gao, X., Luo, G. N., Gong, X. Z., Garofalo, A. M., Li, J., and Wan, B. N. Thu .
"Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations". United States. https://doi.org/10.1088/1741-4326/aa8bf3. https://www.osti.gov/servlets/purl/1471878.
@article{osti_1471878,
title = {Evidence and modeling of 3D divertor footprint induced by lower hybrid waves on EAST with tungsten divertor operations},
author = {Feng, W. and Wang, L. and Rack, M. and Liang, Y. and Guo, H. Y. and Xu, G. S. and Xu, J. C. and Liu, J. B. and Sun, Y. W. and Jia, M. N. and Yang, Q. Q. and Zhang, B. and Zou, X. L. and Liu, H. and Zhang, T. and Ding, F. and Chen, J. B. and Duan, Y. M. and Zheng, X. W. and Dai, S. Y. and Deng, G. Z. and Chen, R. and Hu, G. H. and Yan, N. and Si, H. and Liu, S. C. and Xu, S. and Wang, M. and Li, M. H. and Ding, B. J. and Wingen, Andreas and Huang, J. and Gao, X. and Luo, G. N. and Gong, X. Z. and Garofalo, A. M. and Li, J. and Wan, B. N.},
abstractNote = {Here, three dimensional (3D) divertor particle flux footprints induced by the lower hybrid wave (LHW) have been systematically investigated in the EAST superconducting tokamak during the recent experimental campaign. We find that the striated particle flux (SPF) peaks away from the strike point (SP) closely fit the pitch of the edge magnetic field line for different safety factors q 95, as predicted by a field line tracing code taking into account the helical current filaments (HCFs) in the scrape-off-layer (SOL). As LHW power increases, it requires the fuelling to be increased e.g. by super molecular beam injection (SMBI), to maintain a similar plasma density, which may be attributed to the pump-out effect due to LHW, and may thus be beneficial for EAST steady state operations. The 3D SPF structure is observed with a LHW power threshold (P LHW ~ 0.9 MW). The ratio of the particle fluxes between SPF and outer strike point (OSP), i.e. ${{\Gamma }_{{\rm ion},{\rm SPF}}}/{{\Gamma }_{{\rm ion},{\rm OSP}}}$ , increases with the LHW power. Upon transition to divertor detachment, the particle flux at the main OSP decreases, as expected, however, the particle flux at SPF continues increasing, in contrast to the RMP-induced striations that vanish with increasing divertor density. In addition, we also find that the in–out asymmetry of the 3D particle flux footprint pattern exhibits a clear dependence on the toroidal field direction (B × ∇ B ↓ and B × ∇ B↑). Experiments using neon impurity seeding show a promising capability in 3D particle and heat flux control on EAST. LHW-induced particle and heat flux striations are also present in the H-mode plasmas, reducing the peak heat flux and erosion at the main strike point, thus facilitating long-pulse operation with a new steady-state H-mode over 60s being recently achieved in EAST.},
doi = {10.1088/1741-4326/aa8bf3},
journal = {Nuclear Fusion},
number = 12,
volume = 57,
place = {United States},
year = {Thu Oct 26 00:00:00 EDT 2017},
month = {Thu Oct 26 00:00:00 EDT 2017}
}
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Works referenced in this record:
Chapter 4: Power and particle control
journal, June 2007
- Loarte, A.; Lipschultz, B.; Kukushkin, A. S.
- Nuclear Fusion, Vol. 47, Issue 6
Key plasma wall interaction issues towards steady state operation
journal, June 2007
- Tsitrone, E.
- Journal of Nuclear Materials, Vol. 363-365
Magnetic Topology Changes Induced by Lower Hybrid Waves and their Profound Effect on Edge-Localized Modes in the EAST Tokamak
journal, June 2013
- Liang, Y.; Gong, X. Z.; Gan, K. F.
- Physical Review Letters, Vol. 110, Issue 23
Edge stability and transport control with resonant magnetic perturbations in collisionless tokamak plasmas
journal, May 2006
- Evans, Todd E.; Moyer, Richard A.; Burrell, Keith H.
- Nature Physics, Vol. 2, Issue 6
Overview of the results on divertor heat loads in RMP controlled H-mode plasmas on DIII-D
journal, August 2009
- Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. E.
- Nuclear Fusion, Vol. 49, Issue 9
Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET
journal, May 2012
- Harting, D. M.; Liang, Y.; Jachmich, S.
- Nuclear Fusion, Vol. 52, Issue 5
Recent advances in long-pulse high-confinement plasma operations in Experimental Advanced Superconducting Tokamak
journal, May 2014
- Guo, H. Y.; Li, J.; Wan, B. N.
- Physics of Plasmas, Vol. 21, Issue 5
Hot spots generated by low hybrid wave absorption in the SOL on the EAST tokamak
journal, July 2013
- Gan, K. F.; Li, M. H.; Wang, F. M.
- Journal of Nuclear Materials, Vol. 438
Absorption of lower hybrid waves in the scrape off layer of a diverted tokamak
journal, August 2010
- Wallace, G. M.; Parker, R. R.; Bonoli, P. T.
- Physics of Plasmas, Vol. 17, Issue 8
Upgrade of Langmuir probe diagnostic in ITER-like tungsten mono-block divertor on experimental advanced superconducting tokamak
journal, August 2016
- Xu, J. C.; Wang, L.; Xu, G. S.
- Review of Scientific Instruments, Vol. 87, Issue 8
Measurement of Radiated Power Loss on EAST
journal, October 2011
- Duan, Yanmin; Hu, Liqun; Mao, Songtao
- Plasma Science and Technology, Vol. 13, Issue 5
Footprint structures due to resonant magnetic perturbations in DIII-D
journal, April 2009
- Wingen, A.; Evans, T. E.; Spatschek, K. H.
- Physics of Plasmas, Vol. 16, Issue 4
High resolution numerical studies of separatrix splitting due to non-axisymmetric perturbation in DIII-D
journal, April 2009
- Wingen, A.; Evans, T. E.; Spatschek, K. H.
- Nuclear Fusion, Vol. 49, Issue 5
A long-pulse high-confinement plasma regime in the Experimental Advanced Superconducting Tokamak
journal, November 2013
- Li, J.; Guo, H. Y.; Wan, B. N.
- Nature Physics, Vol. 9, Issue 12
Enhanced heat flux in the scrape-off layer due to electrons accelerated in the near field of lower hybrid grills
journal, June 1998
- Goniche, M.; Guilhem, D.; Bibet, P.
- Nuclear Fusion, Vol. 38, Issue 6
Modification of H-mode pedestal structure with lower hybrid waves on Alcator C-Mod
journal, May 2010
- Hughes, J. W.; Hubbard, A. E.; Wallace, G.
- Nuclear Fusion, Vol. 50, Issue 6
Driving mechanism of sol plasma flow and effects on the divertor performance in JT-60U
journal, March 2004
- Asakura, N.; Takenaga, H.; Sakurai, S.
- Nuclear Fusion, Vol. 44, Issue 4
Characteristics of the divertor plasma in neutral-beam-heated ASDEX discharges
journal, July 1983
- Shimomura, Y.; Keilhacker, M.; Lackner, K.
- Nuclear Fusion, Vol. 23, Issue 7
The isotope effect on the L mode density limit in JET hydrogen, deuterium and tritium divertor plasmas
journal, August 1999
- Maggi, C. F.; Monk, R. D.; Horton, L. D.
- Nuclear Fusion, Vol. 39, Issue 8
Assessment of divertor heat load with and without external magnetic perturbation
journal, May 2017
- Sieglin, B.; Eich, T.; Faitsch, M.
- Nuclear Fusion, Vol. 57, Issue 6
Changes in divertor conditions in response to changing core density with RMPs
journal, June 2017
- Briesemeister, A. R.; Ahn, J. -W.; Canik, J. M.
- Nuclear Fusion, Vol. 57, Issue 7
3D Edge Modeling and Island Divertor Physics
journal, April 2004
- Feng, Y.; Sardei, F.; Kisslinger, J.
- Contributions to Plasma Physics, Vol. 44, Issue 13
Works referencing / citing this record:
Multiple striated heat fluxes patterns on the EAST first wall generated by lower hybrid wave absorption in the scrape-off layer
journal, July 2019
- Gan, K. F.; Li, M. H.; Gong, X. Z.
- Physics of Plasmas, Vol. 26, Issue 7
Statistical study of particle flux footprint widths with tungsten divertor in EAST
journal, February 2019
- Liu, X.; Naulin, V.; Xu, J. C.
- Plasma Physics and Controlled Fusion, Vol. 61, Issue 4
Observation of a fully non-inductive H-mode regime dominated by the sporadic-small edge-localized modes in EAST with a tungsten divertor
journal, June 2019
- Zhang, Heng; Chen, Ran; Xu, Guosheng
- Plasma Physics and Controlled Fusion, Vol. 61, Issue 8
Experimental study on the magnetic coherent mode in the H-mode pedestal of EAST
journal, September 2018
- Chen, Ran; Zhang, Heng; Xu, Guosheng
- Nuclear Fusion, Vol. 58, Issue 11
First three-dimensional edge plasma transport simulations with magnetic perturbations induced by lower hybrid waves on EAST
journal, July 2018
- Xu, S.; Rack, M.; Liang, Y.
- Nuclear Fusion, Vol. 58, Issue 10
Electron density calculation based on Stark broadening of D Balmer line from detached plasma in EAST tungsten divertor
journal, August 2018
- Xu, Feng; Ding, Fang; Chen, Xiahua
- Plasma Science and Technology, Vol. 20, Issue 10