Illustration Paolo Ricci

New insights on scrape-off layer plasma turbulence

​Seminar by Paolo Ricci, Swiss Plasma Center, EPFL.

Abstract

One of the greatest uncertainties in the success of ITER and future fusion reactors is related to the turbulent dynamics of the plasma fusion fuel in the scrape-off layer (SOL). The plasma behavior in this region governs the overall confinement properties of the device, regulates the impurity dynamics and the level of fusion ashes, and determines the heat load to the tokamak vessel walls – a showstopper for the whole fusion program if material requirements cannot be met. A project is being carried out in Lausanne focused on deepening our understanding of plasma turbulence in the SOL and the Global Braginskii Solver (GBS) code has been developed for this purpose. By solving the drift-reduced Braginskii equations coupled to a kinetic equation for the neutrals, the code evolves self-consistently the SOL plasma dynamics as it results from neutral recycling, turbulent transport, and plasma losses at the vessel. These simulations have allowed us to advance the basic understanding of SOL turbulence, making progress in the identification of the driving instabilities and in estimating the turbulence saturation amplitude, the SOL pressure scale length, and the generation of intrinsic toroidal rotation. The comparison of our theoretical and simulation results against data from several tokamaks worldwide yielded very good agreement.
Category Seminar
Location: Nexus 4030, meeting room, Fysik Origo, Fysik
Starts: 01 September, 2017, 13:30
Ends: 01 September, 2017, 14:30

Published: Thu 17 Aug 2017. Modified: Fri 01 Sep 2017