English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Conference Paper

Monte Carlo δf simulations of neoclassical phenomena in Tokamak plasmas

MPS-Authors
/persons/resource/persons108681

Bergmann,  A.
Tokamak Theory (TOK), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons110185

Poli,  E.
Tokamak Theory (TOK), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons110124

Peeters,  A. G.
Tokamak Theory (TOK), Max Planck Institute for Plasma Physics, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Bergmann, A., Poli, E., & Peeters, A. G. (2003). Monte Carlo δf simulations of neoclassical phenomena in Tokamak plasmas. In Fusion Energy 2002. Vienna: International Atomic Energy Agency.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0027-3BF5-F
Abstract
Some important neoclassical phenomena are studied with drift-kinetic simulations of the ions: the current which drives neoclassical tearing modes (bootstrap and polarization current) and the bootstrap current at a steep gradient. The δf code HAGIS is used with pitch angle collisions modelled by a Monte Carlo procedure. An equilibrium with circular cross section and (for the island modelling) a single helical perturbation is considered, ITER- and AUG-like parameter are used. We find that the bootstrap current in small islands does not vanish, the full current is observed if the island width is smaller than the orbit width. The results can explain the scaling of the normalized beta at the onset of the NTMs in ASDEX Upgrade. The polarization current due to the island rotation is studied as well and is found to be strongly reduced at small island size. The transition to the collisional limit is only observed at high values of ν/εω. In the banana regime the bootstrap current at a steep density profile is reduced and depends non-locally on the gradient if the orbit width is not small compared to the the gradient length.