Speaker
Masanari Hosokawa
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O2.110.pdf
Modelling of the effects of divertor recycling conditions and toroidal field
direction on divertor power and particle flux asymmetries between and
during ELMs with PARASOL for COMPASS-like plasmas
M. Hosokawa1, A. Loarte1, G.T.A. Huijsmans2, T. Takizuka3, N. Hayashi4, J. Adamek5,
J. Seidl5, J. Horacek5, M. Komm5
1
ITER Organisation, Route de Vinon sur Verdon, 13067 St Paul Lez Durance Cedex, France
2
CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
3
Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
4
National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
5
Institute of Plasma Physics AS CR, Prague, Czech Republic
Particle and energy fluxes to the plasma facing components (PFCs) during edge localized
modes (ELMs) are expected to unacceptably shorten the lifetime of PFCs in ITER [1].
Non-linear MHD simulations of ELMs for ITER have shown that some aspects of empirical
extrapolations, such as the broadening of the ELM power footprint at the divertor plate, may not
apply at the ITER scale [2]. However, these findings are questionable because the particle and
energy transport along the field lines in these MHD simulations are modelled in a fluid
approximation. The ELM transport in the ITER SOL-divertor plasma is essentially collisionless
given the high pedestal plasma temperature. In order to understand the consequences of kinetic
effects on the power and particle fluxes to PFCs by ELMs, particle simulations with PARASOL
[3] have been carried out. Initial 1-D simulations for ITER showed that the in/out asymmetry of
the ELM divertor power/particle fluxes is strongly affected by the magnitude of the ELM
energy loss and by the thermoelectric current flow [4]. In order to understand the 2-D aspects of
the ELM energy flow to the divertor, initial PARASOL-2D simulations for COMPASS-like
tokamak plasmas were carried out in stationary conditions and during ELMs including both the
effects of drifts and divertor recycling [5]. It was found that: (i) the directions of the ion B drift
“normal” and “reversed” had a strong effect on the steady-state in/out heat/particle flux divertor
asymmetries Ein/Eout ~ 0.3 and 1.0 respectively, (ii) the energy load was generally larger during
an ELM at the inner divertor for “normal” B and at the outer divertor for “reversed” B. This
finding is robust to modelling assumptions (recycling ratio, ELM energy loss magnitude) and in
good qualitative agreement with experiment. The paper will report on improved simulations of
COMPASS-like plasmas and the comparison of the results with previous COMPASS
experimental results [6] and those of more recent experiments. Consequences regarding the
comparison between kinetic and fluid modelling for ELMs will be described in the paper.
[1] A. Loarte, et al., Nucl. Fusion 54 (2014) 033007. [4] M. Hosokawa, et al., Proc. 41st EPS Conf. P5.003.
[2] G.T.A. Huijsmans, et al., Nucl. Fusion 53 (2013) [5] M. Hosokawa, et al., 16th PET Workshop, O-07.
123023. [6] J. Adamek, et al. Nucl. Fusion 57 (2017) 022010.
[3] T. Takizuka, Plasma Sci. Technol. 13 (2011) 316.
