{"title":"The impact of helium clusters on the electronic thermal transport properties of tungsten plasma-facing materials at finite temperatures","authors":"Zhao-Zhong Fu , B.C. Pan","doi":"10.1016/j.jnucmat.2024.155255","DOIUrl":null,"url":null,"abstract":"<div><p>In this work, we investigated the impact of different concentrations of helium (He) impurities on the electronic thermal transport properties of tungsten plasma-facing materials (W-PFMs) at finite temperatures using the W-He tight-binding (TB) potential model. We found that the electronic transport performance decreases with increasing He atom concentration at different sites, where the greatest reduction in the electrical conductivity of the system is caused by the introduction of He atoms at neighboring tetrahedral sites. As the temperature increases, the electrical conductivity decreases, while the electronic thermal conductivity increases. Importantly, the higher the temperature is, the weaker the response of the electrical conductivity and electronic thermal conductivity to the He atom concentration. We suggest that this behavior is attributed to the diverse contributions of scattering mechanisms within various temperature ranges. Furthermore, as the temperature increases, the electron scattering mechanism gradually transitions from electron-impurity scattering to electron-electron scattering. Additionally, our calculated atomic resolved electrical conductivity data indicate that at lower temperatures, the electrical conductivity is predominantly contributed by W atoms around the He cluster.</p></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nuclear Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S002231152400357X","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
In this work, we investigated the impact of different concentrations of helium (He) impurities on the electronic thermal transport properties of tungsten plasma-facing materials (W-PFMs) at finite temperatures using the W-He tight-binding (TB) potential model. We found that the electronic transport performance decreases with increasing He atom concentration at different sites, where the greatest reduction in the electrical conductivity of the system is caused by the introduction of He atoms at neighboring tetrahedral sites. As the temperature increases, the electrical conductivity decreases, while the electronic thermal conductivity increases. Importantly, the higher the temperature is, the weaker the response of the electrical conductivity and electronic thermal conductivity to the He atom concentration. We suggest that this behavior is attributed to the diverse contributions of scattering mechanisms within various temperature ranges. Furthermore, as the temperature increases, the electron scattering mechanism gradually transitions from electron-impurity scattering to electron-electron scattering. Additionally, our calculated atomic resolved electrical conductivity data indicate that at lower temperatures, the electrical conductivity is predominantly contributed by W atoms around the He cluster.
在这项研究中,我们利用 W-He 紧结合 (TB) 势模型研究了不同浓度的氦(He)杂质对钨等离子体面材料(W-PFM)在有限温度下的电子热传输特性的影响。我们发现,电子传输性能随着不同位点上 He 原子浓度的增加而降低,其中相邻四面体位点上 He 原子的引入导致系统导电率的最大降低。随着温度的升高,电导率降低,而电子热导率却升高。重要的是,温度越高,电导率和电子热导率对 He 原子浓度的响应越弱。我们认为这种行为是由于在不同温度范围内散射机制的不同贡献造成的。此外,随着温度的升高,电子散射机制逐渐从电子-杂质散射过渡到电子-电子散射。此外,我们计算的原子分辨电导率数据表明,在较低温度下,电导率主要由 He 簇周围的 W 原子贡献。
期刊介绍:
The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome.
The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example.
Topics covered by JNM
Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior.
Materials aspects of the entire fuel cycle.
Materials aspects of the actinides and their compounds.
Performance of nuclear waste materials; materials aspects of the immobilization of wastes.
Fusion reactor materials, including first walls, blankets, insulators and magnets.
Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties.
Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.