Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST

Ding, B. J.; Li, Y. C.; Zhang, L.; Li, M. H.; Wei, W.; Kong, E. H.; Wang, M.; Xu, H. D.; Wang, S. L.; Xu, G. S.; Zhao, L. M.; Hu, H. C.; Jia, H.; Cheng, M.; Yang, Y.; Liu, L.; Zhao, H. L.; Peysson, Y.; Decker, J.; Goniche, M.; Amicucci, L.; Cesario, R.; Tuccillo, A. A.; Baek, S. G.; Parker, R.; Bonoli, P. T.; Paoletti, F.; Yang, C.; Shan, J. F.; Liu, F. K.; Zhao, Y. P.; Gong, X. Z.; Hu, L. Q.; Gao, X.; Wan, B. N.; Li, J. G.

doi:10.7910/DVN/Q3BEMZ

Title: Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST

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Abstract

Two important issues in achieving lower hybrid current drive (LHCD) high confinement plasma in EAST are to improve lower hybrid wave (LHW)-plasma coupling and to drive the plasma current at a high density. Studies in different configurations with different directions of toroidal magnetic field (Bt) show that the density near the antenna is affected by both the radial electric field induced by plasma without a LHW (Er-plasma) in the scrape off layer (SOL), and the radial electric field induced by LHW power (Er-LH) near the grill. Investigations indicate that Er× Btin the SOL leads to a different effect of configuration on the LHW-plasma coupling and Er-LH× Btaccounts for the asymmetric density behaviour in the SOL observed in the experiments, where Eris the total radial electric field in the SOL. Modelling of parametric instability (PI), collisional absorption (CA) and scattering from density fluctuations (SDF) in the edge region, performed considering the parameters of high density LHCD experiments in EAST, has shown that these mechanisms could be responsible for the low current drive (CD) efficiency at high density. Radiofrequency probe spectra, useful for documenting PI occurrence, show sidebands whose amplitude in the case of the lithiated vacuum chamber is smaller than inmore »« less

Publication Date:: Thu Dec 09 04:00:00 UTC 2021

DOE Contract Number:: SC0010492

Research Org.:: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center

Sponsoring Org.:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

OSTI Identifier:: 1887456

DOI:: https://doi.org/10.7910/DVN/Q3BEMZ

Citation Formats


                    Ding, B. J., Li, Y. C., Zhang, L., Li, M. H., Wei, W., Kong, E. H., Wang, M., Xu, H. D., Wang, S. L., Xu, G. S., Zhao, L. M., Hu, H. C., Jia, H., Cheng, M., Yang, Y., Liu, L., Zhao, H. L., Peysson, Y., Decker, J., Goniche, M., Amicucci, L., Cesario, R., Tuccillo, A. A., Baek, S. G., Parker, R., Bonoli, P. T., Paoletti, F., Yang, C., Shan, J. F., Liu, F. K., Zhao, Y. P., Gong, X. Z., Hu, L. Q., Gao, X., Wan, B. N., and Li, J. G. Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST.  United States: N. p., 2021. 
        Web.  doi:10.7910/DVN/Q3BEMZ.

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                    Ding, B. J., Li, Y. C., Zhang, L., Li, M. H., Wei, W., Kong, E. H., Wang, M., Xu, H. D., Wang, S. L., Xu, G. S., Zhao, L. M., Hu, H. C., Jia, H., Cheng, M., Yang, Y., Liu, L., Zhao, H. L., Peysson, Y., Decker, J., Goniche, M., Amicucci, L., Cesario, R., Tuccillo, A. A., Baek, S. G., Parker, R., Bonoli, P. T., Paoletti, F., Yang, C., Shan, J. F., Liu, F. K., Zhao, Y. P., Gong, X. Z., Hu, L. Q., Gao, X., Wan, B. N., & Li, J. G. Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST.  United States.  doi:https://doi.org/10.7910/DVN/Q3BEMZ

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                    Ding, B. J., Li, Y. C., Zhang, L., Li, M. H., Wei, W., Kong, E. H., Wang, M., Xu, H. D., Wang, S. L., Xu, G. S., Zhao, L. M., Hu, H. C., Jia, H., Cheng, M., Yang, Y., Liu, L., Zhao, H. L., Peysson, Y., Decker, J., Goniche, M., Amicucci, L., Cesario, R., Tuccillo, A. A., Baek, S. G., Parker, R., Bonoli, P. T., Paoletti, F., Yang, C., Shan, J. F., Liu, F. K., Zhao, Y. P., Gong, X. Z., Hu, L. Q., Gao, X., Wan, B. N., and Li, J. G. 2021.  
"Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST".  United States.  doi:https://doi.org/10.7910/DVN/Q3BEMZ.  https://www.osti.gov/servlets/purl/1887456. Pub date:Thu Dec 09 04:00:00 UTC 2021

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@article{osti_1887456,

  title        = {Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST},

  author       = {Ding, B. J. and Li, Y. C. and Zhang, L. and Li, M. H. and Wei, W. and Kong, E. H. and Wang, M. and Xu, H. D. and Wang, S. L. and Xu, G. S. and Zhao, L. M. and Hu, H. C. and Jia, H. and Cheng, M. and Yang, Y. and Liu, L. and Zhao, H. L. and Peysson, Y. and Decker, J. and Goniche, M. and Amicucci, L. and Cesario, R. and Tuccillo, A. A. and Baek, S. G. and Parker, R. and Bonoli, P. T. and Paoletti, F. and Yang, C. and Shan, J. F. and Liu, F. K. and Zhao, Y. P. and Gong, X. Z. and Hu, L. Q. and Gao, X. and Wan, B. N. and Li, J. G.},

  abstractNote = {Two important issues in achieving lower hybrid current drive (LHCD) high confinement plasma in EAST are to improve lower hybrid wave (LHW)-plasma coupling and to drive the plasma current at a high density. Studies in different configurations with different directions of toroidal magnetic field (Bt) show that the density near the antenna is affected by both the radial electric field induced by plasma without a LHW (Er-plasma) in the scrape off layer (SOL), and the radial electric field induced by LHW power (Er-LH) near the grill. Investigations indicate that Er× Btin the SOL leads to a different effect of configuration on the LHW-plasma coupling and Er-LH× Btaccounts for the asymmetric density behaviour in the SOL observed in the experiments, where Eris the total radial electric field in the SOL. Modelling of parametric instability (PI), collisional absorption (CA) and scattering from density fluctuations (SDF) in the edge region, performed considering the parameters of high density LHCD experiments in EAST, has shown that these mechanisms could be responsible for the low current drive (CD) efficiency at high density. Radiofrequency probe spectra, useful for documenting PI occurrence, show sidebands whose amplitude in the case of the lithiated vacuum chamber is smaller than in the case of poor lithiation, consistently with growth rates from PI modeling of the respective reference discharges. Since strong lithiation is also expected to diminish the parasitic effect on the LHCD of the remaining possible mechanisms, this appears to be a useful method for improving LHCD efficiency at a high density.},

  doi          = {10.7910/DVN/Q3BEMZ},

  journal      = {},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {Thu Dec 09 04:00:00 UTC 2021},

  month        = {Thu Dec 09 04:00:00 UTC 2021}

}

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DOI: https://doi.org/10.7910/DVN/Q3BEMZ

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