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17–22 Oct 2016
Kyoto International Conference Center
Japan timezone

Synergetic effects of collisions, turbulence and sawtooth crashes on impurity transport.

20 Oct 2016, 08:50
20m
Kyoto International Conference Center

Kyoto International Conference Center

Takaragaike, Sakyo-ku, Kyoto 606-0001 Japan
Oral THC - Magnetic Confinement Theory and Modelling: Confinement Transport & LH Transition

Speaker

Mr Xavier Garbet (CEA)

Description

This paper investigates the interplay of neoclassical, turbulent and MHD processes, which are simultaneously at play when contributing to impurity transport. It is shown that these contributions are not additive, as assumed sometimes. The interaction between turbulence and neoclassical effects leads to less effective thermal screening, i.e. lowers the outward flux due to temperature gradient. This behavior is attributed to poloidal asymmetries of the flow driven by turbulence. Moreover sawtooth crashes play an important role to determine fluxes across the q=1 surface. It is found that the density profile of a heavy impurity differs significantly in sawtoothing plasmas from the one predicted by neoclassical theory when neglecting MHD events. Sawtooth crashes impede impurity accumulation, but also weaken the impurity outflux due to the temperature gradient when the latter is dominant. Hence the combination of turbulent and MHD effects tends to oppose the effect of neoclassical thermal screening.
Country or International Organization France
Paper Number TH/3-1

Primary author

Co-authors

Mr Alain Marx (CEA) Prof. Andrei Smolyakov (U. Saskatchewan) Dr Damien Esteve (CEA) Dr Guilhem Dif-Pradalier (CEA) Dr Guillaume Latu (CEA) Dr Hinrich Lütjens (Ecole Polytechnique) Dr Jae-Heon Ahn (CEA) Dr Jean-François Luciani (Ecole Polytechnique) Mr Olivier Février (CEA) Dr Patrick Maget (CEA) Mr Peter Donnel (CEA) Mr Philippe Ghendrih (CEA-IRFM) Dr Remy Guirlet (CEA) Mrs Sarah Breton (CEA) Mr Timothée Nicolas (NIFS) Dr Virginie Grandgirard (CEA) Dr Yanick SARAZIN (CEA, IRFM) Mrs clarisse bourdelle (CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France.)

Presentation materials