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Title: Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak

Abstract

Plasma discharges with a negative triangularity (δ=-0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (βN=2.7) and confinement characteristic of the high confinement mode (H98y2=1.2) despite the absence of an edge pressure pedestal and no edge localized modes (ELMs). Furthermore, these inner-wall-limited plasmas have a similar global performance as a positive triangularity ((δ=+0.4) ELMing H-mode discharge with the same plasma current, elongation and cross sectional area. For cases both of dominant electron cyclotron heating with Te / Ti=1 and dominant neutral beam injection heating with T_e / T_i=1, turbulent fluctuations over radii 0.5<0.9 were reduced by 10–50% in the negative triangularity shape compared to the matching positive triangularity shape, depending on the radius and conditions.

Authors:
 [1];  [2];  [3];  [3];  [3];  [3];  [4];  [3];  [5];  [3];  [6];  [3];  [3]
  1. Univ. of Texas, Austin, TX (United States)
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Univ. of Wisconsin, Madison, WI (United States)
  5. Univ. of California, Los Angeles, CA (United States)
  6. Lam Research Corp., Fremont, CA (United States)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States); Univ. of Texas, Austin, TX (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1502834
Alternate Identifier(s):
OSTI ID: 1508884
Grant/Contract Number:  
FC02-04ER54698; FG02-97ER54415; FG02-94ER54235; FG02-08ER54984; FG02-08ER54999; AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 122; Journal Issue: 11; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Austin, Max E., Marinoni, A., Walker, M. L., Brookman, M. W., deGrassie, J. S., Hyatt, A. W., McKee, G. R., Petty, C. C., Rhodes, T. L., Smith, S. P., Sung, C., Thome, K. E., and Turnbull, A. D. Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak. United States: N. p., 2019. Web. doi:10.1103/PhysRevLett.122.115001.
Austin, Max E., Marinoni, A., Walker, M. L., Brookman, M. W., deGrassie, J. S., Hyatt, A. W., McKee, G. R., Petty, C. C., Rhodes, T. L., Smith, S. P., Sung, C., Thome, K. E., & Turnbull, A. D. Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak. United States. doi:10.1103/PhysRevLett.122.115001.
Austin, Max E., Marinoni, A., Walker, M. L., Brookman, M. W., deGrassie, J. S., Hyatt, A. W., McKee, G. R., Petty, C. C., Rhodes, T. L., Smith, S. P., Sung, C., Thome, K. E., and Turnbull, A. D. Mon . "Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak". United States. doi:10.1103/PhysRevLett.122.115001. https://www.osti.gov/servlets/purl/1502834.
@article{osti_1502834,
title = {Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak},
author = {Austin, Max E. and Marinoni, A. and Walker, M. L. and Brookman, M. W. and deGrassie, J. S. and Hyatt, A. W. and McKee, G. R. and Petty, C. C. and Rhodes, T. L. and Smith, S. P. and Sung, C. and Thome, K. E. and Turnbull, A. D.},
abstractNote = {Plasma discharges with a negative triangularity (δ=-0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (βN=2.7) and confinement characteristic of the high confinement mode (H98y2=1.2) despite the absence of an edge pressure pedestal and no edge localized modes (ELMs). Furthermore, these inner-wall-limited plasmas have a similar global performance as a positive triangularity ((δ=+0.4) ELMing H-mode discharge with the same plasma current, elongation and cross sectional area. For cases both of dominant electron cyclotron heating with Te / Ti=1 and dominant neutral beam injection heating with T_e / T_i=1, turbulent fluctuations over radii 0.5<0.9 were reduced by 10–50% in the negative triangularity shape compared to the matching positive triangularity shape, depending on the radius and conditions.},
doi = {10.1103/PhysRevLett.122.115001},
journal = {Physical Review Letters},
number = 11,
volume = 122,
place = {United States},
year = {2019},
month = {3}
}

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