144 0

Effect of the Shafranov shift and the gradient of beta on intrinsic momentum transport in up-down asymmetric tokamaks

Title
Effect of the Shafranov shift and the gradient of beta on intrinsic momentum transport in up-down asymmetric tokamaks
Author
이정표
Keywords
tokamaks; plasma turbulence; magnetohydrodynamics; gyrokinetic simulations; transport properties
Issue Date
2016-11
Publisher
IOP PUBLISHING LTD
Citation
PLASMA PHYSICS AND CONTROLLED FUSION, v. 58, NO 12, 125015
Abstract
Tokamaks with up-down asymmetric poloidal cross-sections spontaneously rotate due to turbulent transport of momentum. In this work, we investigate the effect of the Shafranov shift on this intrinsic rotation, primarily by analyzing tokamaks with tilted elliptical flux surfaces. By expanding the Grad-Shafranov equation in the large aspect ratio limit we calculate the magnitude and direction of the Shafranov shift in tilted elliptical tokamaks. The results show that, while the Shafranov shift becomes up-down asymmetric and depends strongly on the tilt angle of the flux surfaces, it is insensitive to the shape of the current and pressure profiles (when the geometry, total plasma current, and average pressure gradient are kept fixed). Next, local nonlinear gyrokinetic simulations of these MHD equilibria are performed with GS2, which reveal that the Shafranov shift can significantly enhance the momentum transport. However, to be consistent, the effect of beta' (i.e. the radial gradient of beta) on the magnetic equilibrium was also included, which was found to significantly reduce momentum transport. Including these two competing effects broadens the rotation profile, but leaves the on-axis value of the rotation roughly unchanged. Consequently, the shape of the beta profile has a significant effect on the rotation profile of an up-down asymmetric tokamak.
URI
https://iopscience.iop.org/article/10.1088/0741-3335/58/12/125015/metahttps://repository.hanyang.ac.kr/handle/20.500.11754/101167
ISSN
0741-3335; 1361-6587
DOI
10.1088/0741-3335/58/12/125015
Appears in Collections:
COLLEGE OF ENGINEERING[S](공과대학) > NUCLEAR ENGINEERING(원자력공학과) > Articles
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE