scholarly journals Neoclassical transport coefficients for tokamaks with bean‐shaped flux surfaces

1991 ◽  
Vol 3 (2) ◽  
pp. 395-399 ◽  
Author(s):  
C. S. Chang ◽  
S. M. Kaye
Keyword(s):  
Transport Coefficients ◽  
Neoclassical Transport

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

Neoclassical transport coefficients for finite-aspect-ratio and bean-shaped tokamak plasmas

1987 ◽  
Vol 30 (4) ◽  
pp. 1152 ◽  
Author(s):  
E. C. Crume ◽  
C. O. Beasley ◽  
S. P. Hirshman ◽  
W. I. van Rij
Keyword(s):  
Aspect Ratio ◽  
Transport Coefficients ◽  
Tokamak Plasmas ◽  
Neoclassical Transport

scholarly journals Benchmarking of the mono-energetic transport coefficients—results from the International Collaboration on Neoclassical Transport in Stellarators (ICNTS)

2011 ◽  
Vol 51 (7) ◽  
pp. 076001 ◽  
Author(s):  
C.D. Beidler ◽  
K. Allmaier ◽  
M.Yu. Isaev ◽  
S.V. Kasilov ◽  
W. Kernbichler ◽  
...  
Keyword(s):  
International Collaboration ◽  
Transport Coefficients ◽  
Neoclassical Transport

scholarly journals The importance of the classical channel in the impurity transport of optimized stellarators

2019 ◽  
Vol 85 (4) ◽  
Author(s):  
S. Buller ◽  
A. Mollén ◽  
S. L. Newton ◽  
H. M. Smith ◽  
I. Pusztai
Keyword(s):  
Electrostatic Potential ◽  
Transport Coefficients ◽  
Magnetic Confinement ◽  
Flux Surface ◽  
Classical Counterpart ◽  
Impurity Transport ◽  
Neoclassical Transport ◽  
Order Of Magnitude ◽  
Classical Transport

In toroidal magnetic confinement devices, such as tokamaks and stellarators, neoclassical transport is usually an order of magnitude larger than its classical counterpart. However, when a high-collisionality species is present in a stellarator optimized for low Pfirsch–Schlüter current, its classical transport can be comparable to the neoclassical transport. In this letter, we compare neoclassical and classical fluxes and transport coefficients calculated for Wendelstein 7-X (W7-X) and Large Helical Device (LHD) cases. In W7-X, we find that the classical transport of a collisional impurity is comparable to the neoclassical transport for all radii, while it is negligible in the LHD cases, except in the vicinity of radii where the neoclassical transport changes sign. In the LHD case, electrostatic potential variations on the flux surface significantly enhance the neoclassical impurity transport, while the classical transport is largely insensitive to this effect in the cases studied.

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