Speaker
Michal Poradzinski
(Department of Nuclear Fusion and Plasma Spectroscopy)
Description
The DEMO device is expected to operate in H-mode. On the other hand it is postulated that the divertor power load cannot exceed 5MW/m2 2 . In case of liquid divertor, vaporizing additionally enhances the plate material flux into the bulk. Impurities with large atomic number (Z) dilute the plasma core less, however, they radiate more in the core than those with smaller Z. Liquid tin (Sn) or lithium (Li) divertors are considered as alternatives to a standard tungsten (W) one.
This paper analyzes a possible operational space for the DEMO device with the liquid tin (Sn) divertor setup. The Sn (Z=50) impurity originating from the sputtering and vaporizing is expected to modify plasma characteristics significantly both in the bulk and in the scrape-off layer. The simulation is performed with the COREDIV code which self-consistently solves radial 1D energy and particle transport equations of plasma and impurities in the core region and 2D multifluid transport in the SOL. Influence of the sputtering, prompt redeposition and evaporation of the liquid Sn divertor is taken into account. An operational space of parameters for power to SOL higher than the L-H threshold and the power to the plate less than the technological limit is found. First simulation without impurity seeding shown, that plasma in DEMO with the Sn divertor characterizes with 84% radiation fraction. However, power to the plate is about 55 MW, which is higher than the limit. In order to reduce power to the plate neon and argon seeding were included. Preliminary results show that in case of Ar seeding power to the plate can be reduced to about 20 MW and in case of Ne seeding reduction to the level of 14MW might be achieved.
Co-authors
Grzegorz Pelka
(Department of Nuclear Fusion and Plasma Spectroscopy, Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland)
Irena Ivanova-Stanik
(Department of Nuclear Fusion and Plasma Spectroscopy, Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland)
Michal Poradzinski
(Department of Nuclear Fusion and Plasma Spectroscopy, Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland)
Roman Zagorski
(Department of Nuclear Fusion and Plasma Spectroscopy, Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland)
