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Title: Improved kinetic neoclassical transport calculation for a low-collisionality QH-mode pedestal

Abstract

The role of neoclassical, anomalous and neutral transport to the overall H-mode pedestal and scrape-off layer (SOL) structure in an ELM-free QH-mode discharge on DIII-D is explored using XGC0, a 5D full-f multi-species particle-in-cell drift-kinetic solver with self-consistent neutral recycling and sheath potentials. The work in this paper builds on previous work aimed at achieving quantitative agreement between the flux-driven simulation and the experimental electron density, impurity density and orthogonal measurements of impurity temperature and flow profiles. Improved quantitative agreement is achieved by performing the calculations with a more realistic electron mass, larger neutral density and including finite-Larmor-radius corrections self-consistently in the drift-kinetic motion of the particles. Consequently, the simulations provide stronger evidence that the radial electric field (Er) in the pedestal is primarily established by the required balance between the loss of high-energy tail main ions against a pinch of colder main ions and impurities. The kinetic loss of a small population of ions carrying a large proportion of energy and momentum leads to a separation of the particle and energy transport rates and introduces a source of intrinsic edge torque. Ion orbit loss and finite orbit width effects drive the energy distributions away from Maxwellian, and describe themore » anisotropy, poloidal asymmetry and local minimum near the separatrix observed in the Ti profile.« less

Authors:
 [1];  [2];  [1];  [2]; ORCiD logo [1];  [2]; ORCiD logo [1]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. General Atomics, San Diego, CA (United States)
Publication Date:
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)
Contributing Org.:
Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, NJ 08543, USA
OSTI Identifier:
1308447
Alternate Identifier(s):
OSTI ID: 1263685; OSTI ID: 1371847; OSTI ID: 1572197
Grant/Contract Number:  
AC02-09CH11466; FC02-04ER54698; FG02-07ER54917; AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 8; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; tokamak; pedestal; electric field; transport; kinetic neoclassical; ion orbit loss; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; tokamak, pedestal, electric field, transport, kinetic neoclassical, ion orbit loss

Citation Formats

Battaglia, D. J., Burrell, K. H., Chang, C. S., deGrassie, J. S., Grierson, B. A., Groebner, R. J., and Hager, R. Improved kinetic neoclassical transport calculation for a low-collisionality QH-mode pedestal. United States: N. p., 2016. Web. doi:10.1088/0741-3335/58/8/085009.
Battaglia, D. J., Burrell, K. H., Chang, C. S., deGrassie, J. S., Grierson, B. A., Groebner, R. J., & Hager, R. Improved kinetic neoclassical transport calculation for a low-collisionality QH-mode pedestal. United States. https://doi.org/10.1088/0741-3335/58/8/085009
Battaglia, D. J., Burrell, K. H., Chang, C. S., deGrassie, J. S., Grierson, B. A., Groebner, R. J., and Hager, R. 2016. "Improved kinetic neoclassical transport calculation for a low-collisionality QH-mode pedestal". United States. https://doi.org/10.1088/0741-3335/58/8/085009. https://www.osti.gov/servlets/purl/1308447.
@article{osti_1308447,
title = {Improved kinetic neoclassical transport calculation for a low-collisionality QH-mode pedestal},
author = {Battaglia, D. J. and Burrell, K. H. and Chang, C. S. and deGrassie, J. S. and Grierson, B. A. and Groebner, R. J. and Hager, R.},
abstractNote = {The role of neoclassical, anomalous and neutral transport to the overall H-mode pedestal and scrape-off layer (SOL) structure in an ELM-free QH-mode discharge on DIII-D is explored using XGC0, a 5D full-f multi-species particle-in-cell drift-kinetic solver with self-consistent neutral recycling and sheath potentials. The work in this paper builds on previous work aimed at achieving quantitative agreement between the flux-driven simulation and the experimental electron density, impurity density and orthogonal measurements of impurity temperature and flow profiles. Improved quantitative agreement is achieved by performing the calculations with a more realistic electron mass, larger neutral density and including finite-Larmor-radius corrections self-consistently in the drift-kinetic motion of the particles. Consequently, the simulations provide stronger evidence that the radial electric field (Er) in the pedestal is primarily established by the required balance between the loss of high-energy tail main ions against a pinch of colder main ions and impurities. The kinetic loss of a small population of ions carrying a large proportion of energy and momentum leads to a separation of the particle and energy transport rates and introduces a source of intrinsic edge torque. Ion orbit loss and finite orbit width effects drive the energy distributions away from Maxwellian, and describe the anisotropy, poloidal asymmetry and local minimum near the separatrix observed in the Ti profile.},
doi = {10.1088/0741-3335/58/8/085009},
url = {https://www.osti.gov/biblio/1308447}, journal = {Plasma Physics and Controlled Fusion},
issn = {0741-3335},
number = 8,
volume = 58,
place = {United States},
year = {Fri Jul 15 00:00:00 EDT 2016},
month = {Fri Jul 15 00:00:00 EDT 2016}
}

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Cited by: 4 works
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Works referenced in this record:

A quarter-century of H-mode studies
journal, November 2007


Analysis of pedestal plasma transport
journal, May 2010


Kinetic neoclassical transport in the H-mode pedestal
journal, July 2014


Advances in understanding quiescent H-mode plasmas in DIII-D
journal, May 2005


Edge radial electric field structure in quiescent H-mode plasmas in the DIII-D tokamak
journal, April 2004


Numerical study of neoclassical plasma pedestal in a tokamak geometry
journal, May 2004


A new bdelta f method for neoclassical transport studies
journal, August 1999


Poloidal asymmetries in edge transport barriersa)
journal, May 2015


Validation of transport models using additive flux minimization technique
journal, October 2013


In–out impurity density asymmetry in the pedestal region of Alcator C-Mod
journal, November 2013


Scrape-off layer features of the QH-mode
journal, March 2003


Measurements of the deuterium ion toroidal rotation in the DIII-D tokamak and comparison to neoclassical theory
journal, May 2012


Plasma flow due to a loss-cone distribution centred around the outboard edge in DIII-D
journal, December 2011


Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes
journal, May 2001


Edge radial electric field structure and its connections to H-mode confinement in Alcator C-Mod plasmas
journal, May 2009


Development and validation of a predictive model for the pedestal height
journal, May 2009


Works referencing / citing this record:

Main ion and impurity edge profile evolution across the L- to H-mode transition on DIII-D
journal, August 2018


Active spectroscopy measurements of the deuterium temperature, rotation, and density from the core to scrape off layer on the DIII-D tokamak (invited)
journal, October 2018