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（稀土钡铜氧化物）第二代涂层导体磁带是紧凑型Tokamak融合反应堆的磁铁材料的最大竞争者，因为它们具有优质的电流携带/磁场产生特性。辐射将各种类型的缺陷引入Rebco晶体晶格，而微观结构中的这些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，辐射倾向于稍微提高超导体的临界电流密度，因为引入的缺陷作为磁通线的有效固定位点的作用，从而在产生电阻之前可以携带更高的电流。但是，随着辐照剂量的增加，缺陷浓度增加，超导性能迅速降解，最终导致超导性的完全丧失。该项目的主要目的是提高人们对用能量颗粒辐射引起的微观结构的变化如何影响商业Rebco涂层导体中的通量固定。对于未来融合磁铁的设计师来说，这是重要的工程信息。该项目将涉及将伯明翰新NNUF设施的中子辐照的样品与在道尔顿坎布里安（Dal​​ton Cumbrian）和萨里离子束设施的代理样品离子辐射的样品进行比较。将使用位于Culham Fusion Energy材料研究设施中的最先进的物理特性测量系统进行刷新前后超导特性的详细表征。这是英国唯一可以在广泛的温度和磁场上测量活动超导体样品的电气和磁性特性的设施，并且获得的结果与步骤程序的磁铁设计直接相关。先进的显微结构表征技术（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）（在钻石光源处）的组合也将用于推断通过辐射引入的缺陷的性质，并将辐照损害与超管属性的变化相关联。将要研究的实际相关性的关键参数是辐照温度（包括在低温温度下的照射）和辐照后退火的影响，以及用于评估离子辐射作为昂贵中子损害实验的代理的弹丸类型。该项目跨越EPSRC能源主题（磁性融合，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UKAEA提供的Culham Fusion Energy中心的英国原子能局（UKAEA）的Holly Campbell博士合作，其中50％由UKAEA提供。这是一项为期4年的“ Fusion CDT”学生资格（牛津材料资金支付的课程费用的一部分）