In ITER, as in any tokamak, the first wall and divertor plasma-facing components (PFC) must provide adequate protection of in-vessel structures, sufficient heat exhaust capability and be compatible ...with the requirements of plasma purity. These functions take on new significance in ITER, which will combine long pulse, high power operation with severe restrictions on permitted core impurity concentrations and which, in addition, will produce transient energy loads on a scale unattainable in today’s devices. The current ITER PFC design has now reached a rather mature stage following the 2007 ITER Design Review. This paper presents the key elements of the design, reviews the physics drivers, essentially thermal load specifications, which have defined the concept and discusses a selection of material and design issues.
The new SOLPS-ITER code package Wiesen, S.; Reiter, D.; Kotov, V. ...
Journal of nuclear materials,
08/2015, Letnik:
463
Journal Article
Recenzirano
The SOLPS-ITER package represents a renewed coupling of the up-to-date parallelized EIRENE Monte-Carlo code and the B2.5 edge plasma solver. Each part of the fluid-kinetic code system has been ...dismantled and analysed. For SOLPS-ITER, full backwards compatibility with previous SOLPS4.3 ITER reference simulations is critical. We present the results of the ongoing comprehensive benchmark activity and discuss how SOLPS-ITER can be tuned to reproduce ITER simulations performed with SOLPS4.3. In particular in SOLPS-ITER a quantitative “metric” to measure the level of code convergence has been implemented, with corresponding code diagnostics carried over from SOLPS4.3, allowing code run times to be accurately compared. Good agreement is found between the two codes in the tests so far. Remaining discrepancies in the solution in front of the divertor targets are likely related to different formulations of the equations and the different discretization schemes used by the codes.
A present topic of high interest in magnetic fusion is the “gap” between near-term and long-term concepts for high heat flux components (HHFC), and in particular for divertors. This paper focuses on ...this issue with the aim of characterizing the international status of current HHFC design concepts for ITER and describing the different technologies needed in the designs being developed for fusion power plants. Critical material and physics aspects are highlighted while evaluating the current readiness level of long-term concepts, identifying the design and R&D gaps, and discussing ways to bridge them.
•Detailed design development plan for the ITER tungsten divertor.•Latest status of the ITER tungsten divertor design.•Brief overview of qualification program for the ITER tungsten divertor and status ...of R&D activity.
In November 2011, the ITER Council has endorsed the recommendation that a period of up to 2 years be set to develop a full-tungsten divertor design and accelerate technology qualification in view of a possible decision to start operation with a divertor having a full-tungsten plasma-facing surface. To ensure a solid foundation for such a decision, a full tungsten divertor design, together with a demonstration of the necessary high performance tungsten monoblock technology should be completed within the required timescale. The status of both the design and technology R&D activity is summarized in this paper.
The MEMOS-U physics model, addressing macroscopic melt motion in large deformation and long displacement regimes, and its numerical schemes are presented. Discussion is centred on the shallow water ...application to the metallic melts induced by hot magnetized plasmas, where phase transitions and electromagnetic responses are pivotal. The physics of boundary conditions with their underlying assumptions are analysed and the sensitivity to experimental input uncertainties is emphasized. The JET transient tungsten melting experiment (Coenen et al 2015 Nucl. Fusion 55 023010) is simulated to illustrate the MEMOS-U predictive power and to highlight key aspects of tokamak melt dynamics.
Impurity seeding has been studied for a carbon-free divertor configuration in ITER using edge/divertor SOLPS code simulations. For high power DT operation, simulations have been performed for varying ...throughput, power, pumping speed, impurity seeding concentration and species and the results have been parameterised. With these scalings as boundary conditions, core simulations have determined the operating window for carbon-free, impurity-seeded operation.
The effect of a hypothetical reduction of the SOL power width on the performance of the ITER divertor is analyzed using the SOLPS4.3 code. A reduction of this width by a factor 3 (down to 1.2mm) is ...found to increase the peak power load only by a factor 1.6 because power dissipation in the partially detached divertor plasma is enhanced. The operating window is smaller, but still exists at 10MW/m2 power load. Full alpha particle power is recovered if the allowed peak power load is a factor 1.5 higher, albeit at reduced Q which still remains above Q=10.
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