Conveners
Modelling
- Bruce Lipschultz (University of York)
Modelling
- Bruce Lipschultz (University of York)
Plasma edge codes are the workhorse for divertor design for future machines. Models that correctly account for kinetic neutrals, anomalous transport, and detailed wall geometry are essential to extrapolate current knowledge towards reactors. Yet, the required highly collisional regimes and large size lead to inacceptable runtimes. We report on the status and remaining challenges of some...
Heat and particle exhaust in tokamaks is determined by a complex interplay between plasma transport processes, including turbulence, and a set of physical phenomena due to the interaction between the plasma, the solid wall, recycling or injected neutrals and intrinsic or seeded impurities. The comprehensive modelling of the physics at play requires a consistent integration of each of these...
Investigations of scaling of power exhaust processes in the SOLPS-ITER database for single-null, Super-X, and X-divertor configurations of the EU-DEMO are conducted and compared to predictions based on the Lengyel model [1 - 6]. A robust solution to power exhaust is one of the main challenges faced by reactor-scale fusion devices. To address the risk that a conventional divertor, as pursued in...
The control of a stable detachment solution that is compatible with both the core and edge may be crucial for the operation of reactor tokamaks in steady-state. In tokamaks there exist various methods of accessing and maintaining detachment, including fuelling, impurity seeding, and varying the heating power of the machine. How detachment is accessed and how its extent from the target...
A viable magnetic fusion power plant has to combine very high plasma density and temperature in the core region, in order to maximize fusion reactions, with cold plasma conditions in the peripheral region compatible with long life expectancy of plasma-facing components. In this contribution, taking inspiration from recent work on DIIID tokamak (see ref. 1), we examine this crucial issue for...
The X-point radiator (XPR) is an attractive scenario to solve the power exhaust problem in future fusion devices. In ASDEX Upgrade (AUG), experiments with an XPR showed a dissipated power fraction larger than 90 %, fully detached divertor targets and ELM suppression with a moderate confinement degradation [1]. Recently, a reduced model [2] was derived to explain the physical mechanisms for...
Divertor and exhaust scenario design for future reactors such as ITER and DEMO heavily rely on plasma edge codes as SOLPS-ITER [1]. In practice, the design process often proceeds through large parameter scans to explore the operational space, whereby divertor shape, magnetic field and model parameters are manually tuned to improve the performance of the design and meet various physics,...
EU-DEMO reactor operation is expected to go beyond the ITER requirements of a semi-detached divertor regime [1], and will have to achieve the even higher levels of dissipation needed to demonstrate a realistic power exhaust solution for a fusion power plant. Sustaining the desired degree of detachment will require reliable real time (RT) control. In addition to the actuators (e.g. the impurity...
