Evaluation of fuelling requirements for core density and divertor heat load control in non-stationary phases of the ITER DT 15 MA baseline scenario

Evaluation of fuelling requirements for core density and divertor heat load control in non-stationary phases of the ITER DT 15 MA baseline scenario

Evaluation of fuelling requirements for core density and divertor heat load control in non-stationary phases of the ITER DT 15 MA baseline scenario 150 150 UKAEA Opendata
UKAEA-CCFE-PR(20)23

Evaluation of fuelling requirements for core density and divertor heat load control in non-stationary phases of the ITER DT 15 MA baseline scenario

To ensure optimal plasma performance at high Qfus for the baseline scenario foreseen for the International Tokamak Experimental Reactor (ITER), fuelling requirements, in particular for non-stationary phases, need to be assessed by means of integrated modelling due to different expected fuelling behaviour and additional challenges that need to be addressed by fuelling control compared to present-day tokamak machines.
The fuelling scheme needs to be adjusted to ensure robust divertor head load control, avoiding complete detachment on the one hand while maintaining low divertor temperatures and heat fluxes to minimise W sputtering and erosion of the plasma facing components (PFCs). At the same time, the core density needs to be controlled to fulfil requirements for the application of neutral beam heating, a robust transition from L-mode to stationary fusion burn, the maximisation of the fusion yield, and for a fast reduction in core particle content in the termination phase.
To evaluate fuelling requirements for core density and divertor heat load control, coupled core+edge+SOL transport modelling calculations have been carried out for the first time that follow the entire ITER plasma evolution from just after X-point formation until the late termination phase to find the most effective ways of fuelling and heating DT plasmas without exceeding ITER operational limits. The most efficient ways to fuel ITER with gas and / or pellet injection have been investigated self-consistently with the integrated core+edge+SOL suite of codes JINTRAC developed at JET.
It is shown that, by appropriate adaptation of gas and pellet fuelling and impurity seeding schemes, it may indeed be possible for ITER to approach the target Qfus ~ 10, and a solution can be found within the given model uncertainties to successfully control the plasma evolution through all transients from the early ramp-up until the late ramp-down phase respecting major operational limits and constraints.

Collection:
Journals
Journal:
Nuclear Fusion
Publisher:
IOP (Institute of Physics)
Published date:
05/05/2020
The published version of this paper is currently under embargo and will be available on 05/05/2021