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Title: Turbulent particle transport as a function of toroidal rotation in DIII-D H-mode plasmas

In this paper we show how changes in toroidal rotation, by controlling the injected torque, affect particle transport and confinement. The toroidal rotation is altered using the co- and counter neutral beam injection (NBI) in low collisionality H-mode plasmas on DIII-D with dominant electron cyclotron heating (ECH). We find that there is no correlation between the toroidal rotation shear and the inverse density gradient, which is observed on AUG when $${{T}_{\text{e}}}/{{T}_{\text{i}}}$$ is varied using ECH (Angioni et al 2011 Phys. Rev. Lett. 107 215003). In DIII-D, we find that in a discharge with balanced torque injection, the $$E\times B$$ shear is smaller than the linear gyrokinetic growth rate for small $${{k}_{\theta}}{{\rho}_{s}}$$ for $$\rho =0.6$$ –0.85. This results in lower particle confinement. In the co- and counter- injected discharges the $$E\times B$$ shear is larger or close to the linear growth rate at the plasma edge and both configurations have higher particle confinement. In order to measure particle transport, we use a small periodic perturbative gas puff. This gas puff perturbs the density profiles and allows us to extract the perturbed diffusion and inward pinch coefficients. We observe a strong increase in the inward particle pinch in the counter-torque injected plasma. Lastly, the calculated quasi-linear particle flux, nor the linear growth rates using TGLF agree with experimental observations.
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [2] ;  [3] ;  [3] ;  [3] ;  [3]
  1. College of William and Mary, Williamsburg, VA (United States)
  2. Univ. of California, Los Angeles, CA (United States)
  3. General Atomics, San Diego, CA (United States)
Publication Date:
Grant/Contract Number:
FC02-04ER54698; FG02-08ER54984; SC0007880
Type:
Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 4; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Research Org:
General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; particle transport; ExB shear; turbulence
OSTI Identifier:
1350091
Alternate Identifier(s):
OSTI ID: 1239851