skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Gyrokinetic neoclassical study of the bootstrap current in the tokamak edge pedestal with fully non-linear Coulomb collisions

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4945615· OSTI ID:1255523

As a follow-up on the drift-kinetic study of the non-local bootstrap current in the steep edge pedestal of tokamak plasma by Koh et al. [Phys. Plasmas 19, 072505 (2012)], a gyrokinetic neoclassical study is performed with gyrokinetic ions and drift-kinetic electrons. Besides the gyrokinetic improvement of ion physics from the drift-kinetic treatment, a fully non-linear Fokker-Planck collision operator—that conserves mass, momentum, and energy—is used instead of Koh et al.'s linearized collision operator in consideration of the possibility that the ion distribution function is non-Maxwellian in the steep pedestal. An inaccuracy in Koh et al.'s result is found in the steep edge pedestal that originated from a small error in the collisional momentum conservation. The present study concludes that (1) the bootstrap current in the steep edge pedestal is generally smaller than what has been predicted from the small banana-width (local) approximation [e.g., Sauter et al., Phys. Plasmas 6, 2834 (1999) and Belli et al., Plasma Phys. Controlled Fusion 50, 095010 (2008)], (2) the plasma flow evaluated from the local approximation can significantly deviate from the non-local results, and (3) the bootstrap current in the edge pedestal, where the passing particle region is small, can be dominantly carried by the trapped particles in a broad trapped boundary layer. In conclusion, a new analytic formula based on numerous gyrokinetic simulations using various magnetic equilibria and plasma profiles with self-consistent Grad-Shafranov solutions is constructed.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
AC02-05CH11231; AC02-06CH11357; AC02-09CH11466; FC02-99ER54512
OSTI ID:
1255523
Alternate ID(s):
OSTI ID: 1246538
Report Number(s):
PPPL-5244; PHPAEN
Journal Information:
Physics of Plasmas, Vol. 23, Issue 4; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 52 works
Citation information provided by
Web of Science

References (44)

Local and global Fokker–Planck neoclassical calculations showing flow and bootstrap current modification in a pedestal journal October 2012
Progress at JET in integrating ITER-relevant core and edge plasmas within the constraints of an ITER-like wall journal February 2015
Bootstrap current for the edge pedestal plasma in a diverted tokamak geometry journal July 2012
Theory of energetic ion transport induced by waves of ion cyclotron range of frequencies in a tokamak plasma journal December 1991
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime journal July 1999
Nonlinear growth of the tearing mode journal January 1973
Numerical study of tokamak equilibria with arbitrary flow journal February 2004
Limitations of bootstrap current models journal March 2014
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes journal May 2002
Poloidal asymmetries in edge transport barriersa) journal May 2015
Finite-aspect-ratio effects on the bootstrap current in tokamaks journal January 1988
Dependence of divertor heat flux widths on heating power, flux expansion, and plasma current in the NSTX journal August 2011
Experimental evidence for the bootstrap current in a tokamak journal November 1995
Validation of Neoclassical Bootstrap Current Models in the Edge of an H -Mode Plasma journal June 2004
Full linearized Fokker–Planck collisions in neoclassical transport simulations journal December 2011
Enhancement of neoclassical transport coefficients by a poloidal electric field in tokamaks journal January 1983
Investigation of the formation of a fully pressure‐driven tokamak* journal May 1994
Plasma transport in stochastic magnetic field caused by vacuum resonant magnetic perturbations at diverted tokamak edge journal October 2010
Stability of tearing modes in tokamak plasmas journal July 1994
Turbulent transport and the scrape-off-layer width journal August 2011
Kinetic neoclassical transport in the H-mode pedestal journal July 2014
Dependence of recycling and edge profiles on lithium evaporation in high triangularity, high performance NSTX H-mode discharges journal August 2015
Neoclassical transport of impurities in tokamak plasmas journal September 1981
Bootstrap current during perpendicular neutral injection in JT-60 journal February 1990
Rotation and density asymmetries in the presence of large poloidal impurity flows in the edge pedestal journal November 2013
Nonlocal neoclassical transport in tokamak and spherical torus experiments journal August 2006
Numerical study of neoclassical plasma pedestal in a tokamak geometry journal May 2004
A fully non-linear multi-species Fokker–Planck–Landau collision operator for simulation of fusion plasma journal June 2016
A Fokker-Planck-Landau collision equation solver on two-dimensional velocity grid and its application to particle-in-cell simulation journal March 2014
Gyrokinetic particle simulation model journal September 1987
Diffusion Driven Plasma Currents and Bootstrap Tokamak journal January 1971
Kinetic calculation of neoclassical transport including self-consistent electron and impurity dynamics journal July 2008
Neoclassical ion thermal conductivity modified by finite banana effects in a tokamak plasma journal June 1997
Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio journal September 1997
Noncircular, finite aspect ratio, local equilibrium model journal April 1998
Full-f gyrokinetic particle simulation of centrally heated global ITG turbulence from magnetic axis to edge pedestal top in a realistic tokamak geometry journal September 2009
Theory of plasma transport in toroidal confinement systems journal April 1976
Experimental Observation of Neoclassical Currents in a Plasma journal July 1984
Bootstrap current in a tokamak journal September 1994
The bootstrap current and its consequences journal December 2000
Global Gyrokinetic Simulation of Tokamak Edge Pedestal Instabilities journal November 2012
Enhancement of the Bootstrap Current in a Tokamak Pedestal journal July 2010
Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry report August 2012
Global Gyrokinetic Simulation of Tokamak Edge Pedestal Instabilities text January 2012

Cited By (15)

Observation of the current driving due to electron temperature redistribution by anomalous Doppler instability in the Experimental Advanced Superconducting Tokamak journal December 2019
Pressure balance in a lower collisionality, attached tokamak scrape-off layer journal July 2019
Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C journal March 2018
An Interactive Visualization System for Large Sets of Phase Space Trajectories journal June 2019
Long-lived coupled peeling ballooning modes preceding ELMs on JET journal March 2019
Nonlinear modeling of the effect of n   =  2 resonant magnetic field perturbation on peeling-ballooning modes in KSTAR journal January 2020
ICRF coupling in ASDEX upgrade magnetically perturbed 3D plasmas journal November 2019
Experimental conditions to suppress edge localised modes by magnetic perturbations in the ASDEX Upgrade tokamak journal July 2018
RABBIT: Real-time simulation of the NBI fast-ion distribution journal July 2018
Role of the pedestal position on the pedestal performance in AUG, JET-ILW and TCV and implications for ITER journal June 2019
Integrated modelling of H-mode pedestal and confinement in JET-ILW journal November 2017
Radiative heat exhaust in Alcator C-Mod I-mode plasmas journal March 2019
Inter-ELM evolution of the edge current density in JET-ILW type I ELMy H-mode plasmas journal June 2018
Cross-verification of neoclassical transport solutions from XGCa against NEO journal October 2019
Experimental conditions to suppress edge localised modes by magnetic perturbations in the ASDEX Upgrade tokamak text January 2018

Similar Records

Gyrokinetic neoclassical study of the bootstrap current in the tokamak edge pedestal with fully non-linear Coulomb collisions
Journal Article · Fri Apr 15 00:00:00 EDT 2016 · Physics of Plasmas · OSTI ID:1255523

Bootstrap current for the edge pedestal plasma in a diverted tokamak geometry
Journal Article · Sun Jul 15 00:00:00 EDT 2012 · Physics of Plasmas · OSTI ID:1255523

Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry
Technical Report · Fri Aug 10 00:00:00 EDT 2012 · OSTI ID:1255523