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Title: A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1

Abstract

Here, a fast edge turbulence suppression event has been simulated in the electrostatic version of the gyrokinetic particle-in-cell code XGC1 in a realistic diverted tokamak edge geometry under neutral particle recycling. The results show that the sequence of turbulent Reynolds stress followed by neoclassical ion orbit-loss driven together conspire to form the sustaining radial electric field shear and to quench turbulent transport just inside the last closed magnetic flux surface. As a result, the main suppression action is located in a thin radial layer around ψ N≃0.96–0.98, where ψ N is the normalized poloidal flux, with the time scale ~0.1 ms.

Authors:
 [1]; ORCiD logo [1]; ORCiD logo [1];  [1];  [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [4];  [5];  [6]; ORCiD logo [7]; ORCiD logo [8]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Univ. of California San Diego, La Jolla, CA (United States)
  3. Univ. of California San Diego, La Jolla, CA (United States); Univ. of York, York (United Kingdom)
  4. MIT Plasma Science and Fusion Center, Cambridge, MA (United States)
  5. Univ. of Colorado, Boulder, CO (United States)
  6. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  7. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  8. PHWorley Consulting, Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1436764
Alternate Identifier(s):
OSTI ID: 1433561
Grant/Contract Number:
AC02-09CH11466; AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 5; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Ku, S., Chang, C. S., Hager, R., Churchill, R. M., Tynan, G. R., Cziegler, I., Greenwald, M., Hughes, J., Parker, S. E., Adams, M. F., D'Azevedo, E., and Worley, P.. A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1. United States: N. p., 2018. Web. doi:10.1063/1.5020792.
Ku, S., Chang, C. S., Hager, R., Churchill, R. M., Tynan, G. R., Cziegler, I., Greenwald, M., Hughes, J., Parker, S. E., Adams, M. F., D'Azevedo, E., & Worley, P.. A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1. United States. doi:10.1063/1.5020792.
Ku, S., Chang, C. S., Hager, R., Churchill, R. M., Tynan, G. R., Cziegler, I., Greenwald, M., Hughes, J., Parker, S. E., Adams, M. F., D'Azevedo, E., and Worley, P.. Wed . "A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1". United States. doi:10.1063/1.5020792.
@article{osti_1436764,
title = {A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1},
author = {Ku, S. and Chang, C. S. and Hager, R. and Churchill, R. M. and Tynan, G. R. and Cziegler, I. and Greenwald, M. and Hughes, J. and Parker, S. E. and Adams, M. F. and D'Azevedo, E. and Worley, P.},
abstractNote = {Here, a fast edge turbulence suppression event has been simulated in the electrostatic version of the gyrokinetic particle-in-cell code XGC1 in a realistic diverted tokamak edge geometry under neutral particle recycling. The results show that the sequence of turbulent Reynolds stress followed by neoclassical ion orbit-loss driven together conspire to form the sustaining radial electric field shear and to quench turbulent transport just inside the last closed magnetic flux surface. As a result, the main suppression action is located in a thin radial layer around ψN≃0.96–0.98, where ψN is the normalized poloidal flux, with the time scale ~0.1 ms.},
doi = {10.1063/1.5020792},
journal = {Physics of Plasmas},
number = 5,
volume = 25,
place = {United States},
year = {Wed Apr 18 00:00:00 EDT 2018},
month = {Wed Apr 18 00:00:00 EDT 2018}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on April 18, 2019
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