München 2019 – wissenschaftliches Programm
P 15.5: Vortrag
Mittwoch, 20. März 2019, 12:50–13:05, HS 21
Towards efficient fuelling control in nuclear fusion devices: investigations at ASDEX Upgrade — •Peter Thomas Lang, Bernhard Ploeckl, and ASDEX Upgrade Team — Max-Planck-Insitut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, Germany
Efficient fuelling will be a critical task in a future nuclear fusion power plant. Basic requirement of any approach is to establish a plasma core density sufficiently high to harvest ample fusion power. This has to be achieved with high efficiency in order to keep the related burden on the fuel cycle and with respect to the stored reservoir of hazardous fuel low. To develop suitable strategies and useful tools for the emerging control and actuation needs, an ambitious R&D program is carried out at ASDEX Upgrade, a reactor relevant all-metal-wall mid-size tokamak. Particle fuelling in the planned EU-DEMO reactor is assigned to the injection of mm sized pellets composed from solid fuel. Investigations anticipated the multi-purpose challenges in a reactor by trying to establish, with restricted diagnostics capabilities, feedback core density control while keeping the plasma performance high. Simultaneously, the isotopic mixture for optimised burn conditions has to be kept. Pellets proved also useful as probe for physics investigations and auxiliary matter injection needs. Our investigations demonstrated pellet fuelling in the high-density high-confinement regime providing control over the relevant parameters; even synergetic effects have been found improving simultaneously both pellet and plasma performance. However, in this pellet created regime the observed plasma behaviour sometimes significantly deviates from extrapolation-based predictions.