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The paper presents results of SOLPS modelling of the edge plasma performance during the low-activation phase of ITER operation. The calculations show that the peak power loading of the divertor targets can reach the reactor-relevant level of 3 to 5 MW m−2, even without the fusion reactions, rendering commissioning of the high heat flux components possible in this phase. Parametrization of the output of the SOLPS runs for the predominantly helium plasma concerned by the studies reported here is performed, thus providing the boundary conditions for modelling of the core and allowing efficient integration of the core and edge models. This approach, using the ASTRA code for core simulations, is applied to the analysis of hydrogen accumulation in helium plasmas due to H pellet injection. The latter is the only available option for early testing of ELM pace-making as an ELM control tool assuming H-mode in hydrogen will not be possible. Critical dilution with H down to 70% He in the core plasma can be reached in only 0.5 to 1 s or even shorter, depending on the assumptions made. [ABSTRACT FROM AUTHOR]

Abstract: The edge plasma of four devices, AUG, JET, ITER and a prototypical DEMO near ignition, is modelled with B2-EIRENE with a linear neutral model, carbon impurity, and variable throughput and scrape-off layer power. The scaling from ITER to DEMO is quantified as a power law scaling in device size, and JET and AUG simulations are compared to this scaling. Compared to ITER at the same scrape-off layer power per unit device volume and the same operating point relative to the edge-based density limit, edge helium density and peak power per unit area is found to be similar, and helium influx lower, for DEMO with impurity seeding. With a full neutral model, helium parameters are improved by a factor 3. Results of core modelling show that ignited operation of DEMO is possible with the impurity seeding required to render peak power loads compatible with a helium-cooled divertor. [Copyright &y& Elsevier]

Abstract: ITER divertor and edge modelling with the ITER B2-EIRENE code including neutral–neutral and molecule–ion collisions has been applied to the ITER reference divertor plasma with the reference low-li equilibrium. The scaling of key parameters such as peak power load, DT influx to the core, helium density and influx with SOL power, edge/core fuelling ratio, pumping speed and ratio electron/ion power ratio has been determined and ASTRA core plasma modelling consistent with these edge boundary conditions have been carried out to determine the operating window. [Copyright &y& Elsevier]

Abstract: The paper presents a review of the development of edge plasma modeling at ITER and of its interaction with the evolving divertor design. The SOLPS (B2-Eirene) code has been developed for, and applied to, the evaluation and the design of the ITER divertor for the last 15 years. With respect to the physics and engineering design, divertor modeling had started as an evaluation tool and has developed into essential design tool synthesizing information from theoretical analysis, experimental studies, and engineering intuition. Examples given in the paper illustrate this process. [Copyright &y& Elsevier]

Abstract: The throughput requirements that the ITER fuelling system must satisfy are estimated considering the major system functions. The ELM pace-making and control of the divertor power loading are found to be the most demanding. The total required throughput makes the basis for the design limitations of 200Pam3/s. [Copyright &y& Elsevier]