Understanding radiation damage mechanisms in high temperature superconductors for fusion applications

了解聚变应用高温超导体的辐射损伤机制

• 批准号: 2742910
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2742910
• 关键词: Understanding; radiation; damage; mechanisms; temperature

REBCO (rare-earth barium copper oxide) 2nd generation coated conductor tapes are a top contender for the magnet material in compact tokamak fusion reactors because of their superior current carrying/magnetic field generating properties. Radiation introduces various types of defect to the REBCO crystal lattice and these changes in microstructure are known to affect key superconducting properties such as critical current density and critical temperature. Initially, at low doses, irradiation tends to improve the critical current density of the superconductor slightly because the defects introduced act as efficient pinning sites for magnetic flux lines, enabling higher currents to be carried before resistance is generated. However, as the irradiation dose increases and the defect concentration increases, the superconducting properties degrade rapidly, eventually resulting in the complete loss of superconductivity. The main aim of this project is to improve understanding of how changes in microstructure induced by irradiation with energetic particles affects flux pinning in commercial REBCO coated conductors. This is vital engineering information for the designers of future fusion magnets. The project will involve comparing samples irradiated with neutrons at the new NNUF facilities in Birmingham with proxy samples ion-irradiated at the Dalton Cumbrian and Surrey Ion Beam Facilities. Detailed characterisation of the superconducting properties pre- and post-irradiation will be carried out using a state-of-the-art Physical Properties Measurement System situated in the Materials Research Facility at Culham Centre for Fusion Energy. This is the only facility in the UK where the electrical and magnetic properties of active superconductor samples can be measured over a wide range of temperatures and magnetic fields, and the results obtained will be of direct relevance to the design of magnets for the STEP programme. A combination of advanced microstructural characterisation techniques including atomic resolution transmission electron microscopy, X-ray diffraction and X-ray spectroscopy (at Diamond Light Source), will also be used to deduce the nature of the defects introduced by irradiation and correlate irradiation damage with changes in superconducting properties. Key parameters of practical relevance that will be investigated are the effects of irradiation temperature (including irradiation at cryogenic temperatures) and post irradiation annealing, as well as the type of projectile for assessing the suitability of ion-irradiation as a proxy for expensive neutron damage experiments. This project spans the EPSRC Energy Theme (Magnetic Fusion, Materials for Energy, Manufacturing Technology) and the Engineering Theme (Manufacturing Technology, Materials Engineering, Engineering Design). The project is in collaboration with Dr Holly Campbell at the UK Atomic Energy Authority (UKAEA), Culham Centre for Fusion Energy, with 50% of the funding being provided by UKAEA.This is a 4-year 'Fusion CDT' Studentship (part of the course fee paid from Oxford Materials funds)

REBCO（稀土氧化钡铜）第二代涂层导体带因其卓越的载流/磁场生成特性而成为紧凑型托卡马克聚变反应堆中磁体材料的顶级竞争者。辐射会给 REBCO 晶格引入各种类型的缺陷，并且已知这些微观结构的变化会影响关键的超导特性，例如临界电流密度和临界温度。最初，在低剂量下，辐照往往会略微提高超导体的临界电流密度，因为引入的缺陷充当磁通线的有效钉扎位点，从而能够在产生电阻之前承载更高的电流。然而，随着辐照剂量的增加和缺陷浓度的增加，超导性能迅速退化，最终导致超导性完全丧失。该项目的主要目的是加深对高能粒子辐照引起的微观结构变化如何影响商业 REBCO 涂层导体中通量钉扎的理解。对于未来聚变磁体的设计者来说，这是至关重要的工程信息。该项目将包括将伯明翰新 NNUF 设施中经中子辐照的样品与道尔顿坎布里亚和萨里离子束设施中经离子辐照的替代样品进行比较。辐照前和辐照后超导特性的详细表征将使用位于卡勒姆聚变能中心材料研究设施的最先进的物理特性测量系统进行。这是英国唯一可以在广泛的温度和磁场范围内测量活性超导体样品的电学和磁学特性的设施，获得的结果将与 STEP 计划的磁体设计直接相关。先进的微观结构表征技术的组合，包括原子分辨率透射电子显微镜、X射线衍射和X射线光谱（在钻石光源），也将用于推断辐照引入的缺陷的性质，并将辐照损伤与变化联系起来。在超导特性方面。将研究的具有实际意义的关键参数是辐照温度（包括低温辐照）和辐照后退火的影响，以及用于评估离子辐照作为昂贵的中子损伤实验的替代物的适用性的射弹类型。该项目涵盖 EPSRC 能源主题（磁聚变、能源材料、制造技术）和工程主题（制造技术、材料工程、工程设计）。该项目与英国原子能管理局 (UKAEA) 卡勒姆聚变能源中心的 Holly Campbell 博士合作，50% 的资金由 UKAEA 提供。这是一项为期 4 年的“聚变 CDT”学生奖学金（课程费用由牛津材料基金支付）