Poloidal electric field due to ICRH and its effect on neoclassical transport

1994 ◽  
Author(s):  
Luigi Vacca
Keyword(s):  
Electric Field ◽  
Neoclassical Transport

Global δf particle simulation of neoclassical transport and ambipolar electric field in general geometry

2004 ◽  
Vol 164 (1-3) ◽  
pp. 178-182 ◽  
Author(s):  
W.X. Wang ◽  
W.M. Tang ◽  
F.L. Hinton ◽  
L.E. Zakharov ◽  
R.B. White ◽  
...  
Keyword(s):  
Electric Field ◽  
Particle Simulation ◽  
Neoclassical Transport ◽  
General Geometry

Monte Carlo Simulation of Neoclassical Transport in Axisymmetric and Ripple Tokamaks

1982 ◽  
Vol 37 (8) ◽  
pp. 899-905 ◽  
Author(s):  
W. Lötz ◽  
J. Nührenberg
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electric Field ◽  
Pitch Angle ◽  
Particle Distribution ◽  
Transport Coefficients ◽  
Angle Scattering ◽  
Wide Range ◽  
Neoclassical Transport

Simple axisymmetric and ripple tokamak model fields are used to compute neoclassical trans-port coefficients by Monte Carlo simulation over a wide range of mean free paths in the approximation of small gyroradius. Further assumptions are a monoenergetic particle distribution which is only subject to pitch angle scattering and a vanishing electric field. Pfirsch-Schlüter, plateau, banana and ripple transport coefficients are obtained. In the ripple regime the description is unified by introducing the concept of an effective ripple. Cases in which ripple transport is diminished due to collisionless detrapping are observed

scholarly journals Collisional transport of impurities with flux-surface varying density in stellarators

2018 ◽  
Vol 84 (4) ◽  
Author(s):  
S. Buller ◽  
H. M. Smith ◽  
P. Helander ◽  
A. Mollén ◽  
S. L. Newton ◽  
...  
Keyword(s):  
Electric Field ◽  
Radial Electric Field ◽  
Magnetic Confinement ◽  
Vacuum Field ◽  
Flux Surface ◽  
Impurity Density ◽  
Impurity Transport ◽  
Neoclassical Transport ◽  
Potential Perturbation ◽  
Analytic Models

High-$Z$impurities in magnetic-confinement devices are prone to develop density variations on the flux surface, which can significantly affect their transport. In this paper, we generalize earlier analytic stellarator calculations of the neoclassical radial impurity flux in the mixed-collisionality regime (collisional impurities and low-collisionality bulk ions) to include the effect of such flux-surface variations. We find that only in the homogeneous density case is the transport of highly collisional impurities (in the Pfirsch–Schlüter regime) independent of the radial electric field. We study these effects for a Wendelstein 7-X (W7-X) vacuum field, with simple analytic models for the potential perturbation, under the assumption that the impurity density is given by a Boltzmann response to a perturbed potential. In the W7-X case studied, we find that larger amplitude potential perturbations cause the radial electric field to dominate the transport of the impurities. In addition, we find that classical impurity transport can be larger than the neoclassical transport in W7-X.

Asymmetry of Neoclassical Transport by Dipole Electric Field

2004 ◽  
Vol 6 (5) ◽  
pp. 2437-2439
Author(s):  
Wang Zhongtian ◽  
Wang Long
Keyword(s):  
Electric Field ◽  
Neoclassical Transport

scholarly journals Analysis of Radial Electric Field Bifurcation in LHD Based on Neoclassical Transport Theory

2003 ◽  
Vol 79 (8) ◽  
pp. 816-820 ◽  
Author(s):  
Masayuki YOKOYAMA ◽  
Katsumi IDA ◽  
Takashi SHIMOZUMA ◽  
Kiyomasa WATANABE ◽  
Shin KUBO ◽  
...  
Keyword(s):  
Electric Field ◽  
Transport Theory ◽  
Radial Electric Field ◽  
Neoclassical Transport
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