scholarly journals Isotopic dependence of impurity transport driven by ion temperature gradient turbulence

2016 ◽  
Vol 23 (11) ◽  
pp. 112301 ◽  
Author(s):  
Weixin Guo ◽  
Lu Wang ◽  
Ge Zhuang
Keyword(s):  
Temperature Gradient ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Impurity Transport ◽  
Isotopic Dependence

Turbulent impurity transport modeling for Alcator C-Mod

2013 ◽  
Vol 79 (5) ◽  
pp. 837-846 ◽  
Author(s):  
X. R. FU ◽  
W. HORTON ◽  
I. O. BESPAMYATNOV ◽  
W. L. ROWAN ◽  
S. BENKADDA ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Particle Transport ◽  
Eigenvalue Problems ◽  
Ion Temperature ◽  
Transport Barrier ◽  
Quasilinear Theory ◽  
Ion Temperature Gradient ◽  
Drift Wave ◽  
Impurity Density ◽  
Impurity Transport

AbstractTurbulent particle transport is investigated with a quasilinear theory that is motivated by the boron impurity transport experiments in the Alcator C-Mod. Eigenvalue problems for sets of reduced fluid equations for multi-component plasmas are solved for the self-consistent fluctuating field vectors composed of the electric potential φ, the main ion density δni, the impurity density δnz and the ion temperature fluctuation δTi. For Alcator C-Mod parameters, we investigate two drift wave models: (1) the density-gradient-driven impurity drift wave and (2) the ion-temperature-gradient-driven ion temperature gradient (ITG) mode. Analytic and numerical results for particle transport coefficients are derived and compared with the transport data and the neoclassical theory. We explore the ability of the model to explain impurity density profiles in three confinement regimes: H-mode, I-mode and internal transport barrier (ITB) regime in C-Mod. Related experiments reported on the Large Helical Device are briefly discussed.

scholarly journals Turbulent impurity transport simulations in Wendelstein 7-X plasmas

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
J. M. García-Regaña ◽  
M. Barnes ◽  
I. Calvo ◽  
F. I. Parra ◽  
J. A. Alcusón ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Ion Temperature ◽  
Trace Impurities ◽  
Ion Temperature Gradient ◽  
Electron Temperature Gradient ◽  
Impurity Transport ◽  
Impurity Species ◽  
Nonlinear Simulations ◽  
Electron Mode ◽  
Mode Tem

A study of turbulent impurity transport by means of quasilinear and nonlinear gyrokinetic simulations is presented for Wendelstein 7-X (W7-X). The calculations have been carried out with the recently developed gyrokinetic code stella. Different impurity species are considered in the presence of various types of background instabilities: ion temperature gradient (ITG), trapped electron mode (TEM) and electron temperature gradient (ETG) modes for the quasilinear part of the work; ITG and TEM for the nonlinear results. While the quasilinear approach allows one to draw qualitative conclusions about the sign or relative importance of the various contributions to the flux, the nonlinear simulations quantitatively determine the size of the turbulent flux and check the extent to which the quasilinear conclusions hold. Although the bulk of the nonlinear simulations are performed at trace impurity concentration, nonlinear simulations are also carried out at realistic effective charge values, in order to know to what degree the conclusions based on the simulations performed for trace impurities can be extrapolated to realistic impurity concentrations. The presented results conclude that the turbulent radial impurity transport in W7-X is mainly dominated by ordinary diffusion, which is close to that measured during the recent W7-X experimental campaigns. It is also confirmed that thermodiffusion adds a weak inward flux contribution and that, in the absence of impurity temperature and density gradients, ITG- and TEM-driven turbulence push the impurities inwards and outwards, respectively.

scholarly journals Short wavelength ion temperature gradient turbulence

2012 ◽  
Vol 19 (10) ◽  
pp. 102508 ◽  
Author(s):  
J. Chowdhury ◽  
S. Brunner ◽  
R. Ganesh ◽  
X. Lapillonne ◽  
L. Villard ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Short Wavelength ◽  
Ion Temperature ◽  
Ion Temperature Gradient
Sign in / Sign up

Export Citation Format

Share Document