Methods for reduction of time averaged power fluxes in presence of RMP field on ITER.

0484390 - ÚFP 2018 RIV DE eng C - Conference Paper (international conference)
Kripner, Lukáš - Urban, Jakub - Loarte, A. - Cahyna, Pavel - Evans, T. - Schmitz, O. - Pánek, Radomír
Methods for reduction of time averaged power fluxes in presence of RMP field on ITER.
643. WE-Heraeus-Seminar: Impact of 3D Magnetic Fields on Hot Plasmas. Vol. 643. Jülich: Forschungszentrum Jülich GmbH, 2017 - (Liang, Y.; Sunn Pedersen, T.; Schmitz, O.; Günter, S.), č. článku P3. WE-Heraeus-Seminar, 643. ISBN N.
[WE-Heraeus-Seminar: Impact of 3D magnetic fields on hot plasmas/643./. Bad Honnef (DE), 22.05.2017-24.05.2017]
R&D Projects: GA ČR(CZ) GA16-24724S
Institutional support: RVO:61389021
Keywords : RMP * ITER * Tangle Distance
OECD category: Fluids and plasma physics (including surface physics)

The presence of Edge Localized Modes (ELMs) in large tokamak devices like ITER can lead to exposure of plasma facing components (PFCs) to extremely high power fluxes and consequential melting of PFCs. A very promising method for ELM mitigation and/or suppression is the application of non-axisymmetric magnetic fields, which cause Resonant Magnetic Perturbations (RMPs). However, the application of RMPs can lead to splitting of the strike points into multiple lobes and thus to a non-uniform distribution of the power loads on the divertor. While the ITER plasma in the proximity of a strike-point should be detached, the plasma far from the strike-point remains attached and the increase of the localized power loads in that area can damage the divertor. In this poster, we will present methods that are expected to decrease the time-averaged value of the power load on the divertor. The methods are based on temporal variations of the currents in RMP coils during the discharge. Such a study requires calculations of broad range of target power flux distribution, which is a very demanding process for classical kinetic codes. As a prerequisite for these kinetic simulations we are using the Tangle Distance method [1], which is, due to its analytical nature, capable of efficiently computing a wide range of scenarios. We propose optimized RMP coil currents waveforms with lower ITER LM coils loads than the previously suggested rigid current rotation. [1] Cahyna, P., Peterka, M. et al. Nucl. Fusion (2014), 54(6), 064002.
Permanent Link: http://hdl.handle.net/11104/0279558