Abstract Towards the realization of nuclear fusion, a future reactor must provide efficient and safe power exhaust through both the divertor and FW. Recent studies suggest that the greatest engineering challenges of plasma-facing components (PFCs) may arise from the occurrence of plasma transients, when extreme heat fluxes are expected. In severe cases, extensive surface vaporization, melting and re-solidification may lead to excessive degradation of conventional PFCs. An eventual failure would compromise the reactor safety as well as its prompt return to normal operation. A sacrificial limiter provided with a micro-engineered substrate material is being investigated for DEMO to cope with the harsh conditions occurring during unmitigated plasma disruptions. Among the possible solutions, innovative materials such as tungsten (W) based lattice structures can be tailored to meet functional requirements and prevent severe failures. As a further step in this direction, an equivalent solid model, originally developed and validated for open-cell Al foams, was transferred to W foams and the scaling law of its thermo-physical properties evaluated as a function of the most influential parameters. In the present work, a design optimization tool for the thermal behavior of the substrate material is presented. The latter is modeled as a homogeneous material having equivalent properties. A parametric design study was carried out to assess their impact on the global behavior of the PFC. Independent combinations of equivalent thermal conductivity and density have been applied to the substrate material by scaling the corresponding properties of bulk W. For each design point, results were tabulated and compared with user-defined operating requirements. Afterwards, a post-processing routine was implemented for effective visualization of the space of solutions. Ultimately, tailored lattice structures potentially able to fulfill the operating requirements are proposed. An existing solid model for open-cell W foams was employed to design the features of such material based on the results of the parametric study.

中文翻译：

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DEMO牺牲限幅器基板材料的参数化设计研究

摘要 为了实现核聚变，未来的反应堆必须通过偏滤器和 FW 提供高效和安全的功率排放。最近的研究表明，当预计会出现极端热通量时，等离子体瞬变的发生可能会引起面向等离子体组件 (PFC) 的最大工程挑战。在严重的情况下，大量的表面汽化、熔化和重新凝固可能会导致传统 PFC 的过度降解。最终的故障将危及反应堆的安全以及其迅速恢复正常运行。DEMO 正在研究提供有微工程基板材料的牺牲限制器，以应对在未缓解的等离子体破裂期间发生的恶劣条件。在可能的解决方案中，可以定制钨 (W) 基晶格结构等创新材料，以满足功能要求并防止严重故障。作为朝着这个方向进一步迈出的一步，最初为开孔铝泡沫开发和验证的等效实体模型被转移到 W 泡沫，并将其热物理特性的标度定律评估为最有影响的参数的函数。在目前的工作中，提出了一种用于基板材料热行为的设计优化工具。后者被建模为具有等效属性的均质材料。进行了参数化设计研究以评估它们对 PFC 全局行为的影响。通过缩放体 W 的相应属性，等效热导率和密度的独立组合已应用于基板材料。对于每个设计点，结果都被制成表格并与用户定义的操作要求进行比较。之后，实施了后处理例程，以有效地可视化解决方案的空间。最终，提出了可能能够满足操作要求的定制晶格结构。基于参数研究的结果，采用现有的开孔 W 泡沫实体模型来设计这种材料的特征。提出了可能能够满足操作要求的定制晶格结构。基于参数研究的结果，采用现有的开孔 W 泡沫实体模型来设计这种材料的特征。提出了可能能够满足操作要求的定制晶格结构。基于参数研究的结果，采用现有的开孔 W 泡沫实体模型来设计这种材料的特征。