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Title: Advances in the steady-state hybrid regime in DIII-D – a fully non-inductive, ELM-suppressed scenario for ITER

Journal Article · · Nuclear Fusion
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  1. General Atomics, San Diego, CA (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Columbia Univ., New York, NY (United States)
  5. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  6. Univ. of Wisconsin, Madison, WI (United States)
  7. Univ. of California San Diego, La Jolla, CA (United States)
  8. Oak Ridge Associated Univ., Oak Ridge, TN (United States)
  9. Univ. of California, Irvine, CA (United States)

Here, the hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated with ELM suppression by applying an odd parity n=3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in the DIII-D tokamak with high beta (< β> ≤ 2.8%) and high confinement (H98y2 ≤ 1.4) in the ITER similar shape have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. The n=3 RMP causes surprisingly little increase in thermal transport during ELM suppression. Poloidal magnetic flux pumping in hybrid plasmas maintains q above 1 without loss of current drive efficiency, except that experiments show that extremely peaked ECCD profiles can create sawteeth. During ECCD, Alfvén eigenmode (AE) activity is replaced by a more benign fishbone-like mode, reducing anomalous beam ion diffusion by a factor of 2. While the electron and ion thermal diffusivities substantially increase with higher ECCD power, the loss of confinement can be offset by the decreased fast ion transport resulting from AE suppression. Extrapolations from DIII-D along a dimensionless parameter scaling path as well as those using self-consistent theory-based modeling show that these ELM-suppressed, fully non-inductive hybrids can achieve the Qfus = 5 ITER steady-state mission.

Research Organization:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC05-06OR23100; AC02-09CH11466; FC02-05ER54809; FG02-04ER54761; FG02-08ER54999; AC52-07NA27344; FC02-04ER54698; SC-G903402
OSTI ID:
1373696
Alternate ID(s):
OSTI ID: 1374556; OSTI ID: 1845199
Report Number(s):
LLNL-JRNL-830740
Journal Information:
Nuclear Fusion, Vol. 57, Issue 11; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 19 works
Citation information provided by
Web of Science

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Cited By (8)

DIII-D research towards establishing the scientific basis for future fusion reactors journal June 2019
Hybrid simulations of fishbone instabilities and Alfvén eigenmodes in DIII-D tokamak journal December 2018
Key effects on the confinement improvement of the ASDEX Upgrade hybrid scenario journal September 2019
Heat transport driven by the ion temperature gradient and electron temperature gradient instabilities in ASDEX Upgrade H-modes journal August 2019
Integrated modeling of high β N steady state scenario on DIII-D journal January 2018
Grassy-ELM regime with edge resonant magnetic perturbations in fully noninductive plasmas in the DIII-D tokamak journal July 2018
Analysis of Alfven eigenmode destabilization in ITER using a Landau closure model journal June 2019
Analysis of Alfven Eigenmode destabilization in ITER using a Landau closure model text January 2019