Speaker
Bernhard Ploeckl
(Max Planck Institute for Plasma Physics)
Description
The Demonstration Fusion Power Reactor (DEMO) is supposed to be the step in between ITER and the first commercial fusion power plant. In the framework of one mission of the “Work plan for the roadmap to fusion energy 2014-2018” a work package Tritium, Fuelling and Vacuum (TFV) was launched. As part of this project, the examination of requirements for the matter injection system is ongoing covering all aspects of plasma operation like pre-fill, ramp-up and steady state including plasma enhancement gases.
In a first step, requirements for keeping steady state burning plasmas were elaborated. Related modelling activities indicated that only sufficiently deep fuel deposition can achieve target operational parameters. Hence, suitable techniques had to be identified and evaluated with respect to their availability and capability. Finally, cryogenic pellet injection was chosen as the most realistic option for core fuelling of the plasma. From modelling activities, assuming for the pellet mass the ITER reference value, required launching speeds were derived, with respect to different injection geometries. Several techniques for pellet injection have been benchmarked in view of the defined requirements.
Gas puffing and the respective technical system are necessary for pre-fill, ramp-up and plasma confinement enhancement. The ITER GIS is assessed in view of suitability for DEMO. The tubing system and the manifold concept can be adopted. The Gas Valve Box (GVB) is considered not to be an optimum solution for DEMO. Instead of this GVB, a pressure based RUN/VENT flow regulation and injection system is proposed in order to meet DEMO requirements. The principle of this system is described as well as some considerations about injection locations; further orienting gas flux numbers are provided.
The next step in the TFV sub project “matter injection” will be to work out a conceptual design for the pellet injection system.
Co-authors
Antonio Frattolillo
(ENEA C.R. Frascati, 00044 Frascati, Rome, Italy)
Bernard Pegurie
(CEA-IRFM, 13108 Saint-Paul-lez-Durance, France)
Bernhard Ploeckl
(Max Planck Institute for Plasma Physics, 85748 Garching, Germany)
Christian Day
(Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany)
Hartmut Zohm
(Max Planck Institute for Plasma Physics, 85748 Garching, Germany)
Peter Thomas Lang
(Max Planck Institute for Plasma Physics, 85748 Garching, Germany)
Yuri Igitkhanov
(Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany)
