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Title: Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER

Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changes in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. Finally, for a range of E×B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.
Authors:
 [1] ;  [2] ; ORCiD logo [2] ;  [3] ;  [4] ;  [4] ;  [5] ;  [6] ;  [2]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. General Atomics, San Diego, CA (United States)
  3. Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics
  4. Univ. of Texas, Austin, TX (United States)
  5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
  6. Univ. of California, Los Angeles, CA (United States)
Publication Date:
Grant/Contract Number:
FG02-08ER54999; FG03-97ER54415; AC02-09CH11466; FC02-04ER54698; FG02- 08ER54984; FG02-04ER54235; FG02-07ER54917
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 2; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Contributing Orgs:
DIII-D Team
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
OSTI Identifier:
1432047
Alternate Identifier(s):
OSTI ID: 1420351; OSTI ID: 1462499

Grierson, B. A., Staebler, G. M., Solomon, W. M., McKee, G. R., Holland, C., Austin, M., Marinoni, A., Schmitz, L., and Pinsker, R. I.. Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER. United States: N. p., Web. doi:10.1063/1.5011387.
Grierson, B. A., Staebler, G. M., Solomon, W. M., McKee, G. R., Holland, C., Austin, M., Marinoni, A., Schmitz, L., & Pinsker, R. I.. Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER. United States. doi:10.1063/1.5011387.
Grierson, B. A., Staebler, G. M., Solomon, W. M., McKee, G. R., Holland, C., Austin, M., Marinoni, A., Schmitz, L., and Pinsker, R. I.. 2018. "Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER". United States. doi:10.1063/1.5011387.
@article{osti_1432047,
title = {Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER},
author = {Grierson, B. A. and Staebler, G. M. and Solomon, W. M. and McKee, G. R. and Holland, C. and Austin, M. and Marinoni, A. and Schmitz, L. and Pinsker, R. I.},
abstractNote = {Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changes in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. Finally, for a range of E×B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.},
doi = {10.1063/1.5011387},
journal = {Physics of Plasmas},
number = 2,
volume = 25,
place = {United States},
year = {2018},
month = {2}
}