Impact of simultaneous W deposition and He plasma exposure on mechanical properties of tungsten

同时钨沉积和氦等离子体暴露对钨机械性能的影响

• 批准号: 2796229
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2796229
• 关键词: Impact; simultaneous; deposition; He; plasma

Tungsten is a candidate material for plasma facing components in future fusion reactors such as STEP and DEMO and is the chosen material for the diverter in ITER. The influence of He plasma interactions with tungsten is a fertile area of study with extensive work having been carried out a variety of fusion relevant temperature, fluences and ion energies. The influence of He has been shown to vary at different temperatures with smaller nanobubbles formed at less than 873 K, larger ones above this temperature and a nanostructure knows as fuzz at temperatures between 900-2000 K, with larger voids formed at temperatures above 2000 K. He interactions with tungsten has also been shown to have an influence on the recrystallization properties of tungsten which is related to the temperature of irradiation and consequently the size of bubble formation. This is of interest as recrystallization influences the mechanical performance of tungsten and may increase the likelihood of micro-cracking during operations at high temperatures. Recent work has shown that the presence of tungsten particles during He plasma irradiation has resulted in the enhanced formation of fuzz. This could be of interest for future fusion reactors where there will be some sputtered tungsten present in the plasma. It is of interest to see what the simultaneous impact of deposition of tungsten from an external source with He irradiation at lower temperatures than those required for fuzz formation will be in the nanobubble formation regime and additionally whether this influences the retardation of recrystallization that has been observed following He exposure of tungsten previously. In order to investigate this process, He plasma exposures with simultaneous tungsten deposition will be carried out in collaboration with Prof. Cormac Corr at ANU on tungsten material relevant to the UK Atomic Atomic Energy Authority 'STEP' (Spherical Tokamak for Energy Production) programme. Annealing studies will be carried out on these samples. Following this time will be applied for to use diffraction techniques using the national lab facilities at Harwell in order to measure He bubble size in the exposed samples, which will be correlated to recrystallization via microscopy techniques at Manchester. This is of vital performance in order to understand the engineering performance of future tungsten components and their suitability.The objectives of the project will be to:Carry out simultaneous He irradiation and tungsten deposition on STEP relevant tungsten material at a range of temperatures and fluencesCharacterise the He bubble sizes using imaging and small-angle scattering techniquesCorrelate the bubble formation with impact on recrystallization/other mechanical properties

钨是未来聚变反应堆(如STEP和DEMO)中面向等离子体的部件的候选材料，也是ITER中偏转器的首选材料。氦等离子体与钨相互作用的影响是一个丰富的研究领域，已经开展了各种与聚变相关的温度、通量和离子能量的工作。氦的影响在不同的温度下是不同的，在低于873K时形成较小的纳米气泡，高于873K时形成较大的纳米气泡，在900-2000K之间形成纳米结构，在高于2000K时形成较大的空洞。与钨的相互作用也被证明对钨的再结晶性能产生影响，这与辐照温度有关，从而与气泡形成的大小有关。这是有意义的，因为再结晶会影响钨的机械性能，并可能增加高温操作过程中微裂纹的可能性。最近的工作表明，在He等离子体辐照过程中，钨粒子的存在导致了毛羽的增强形成。这可能会对未来的聚变反应堆感兴趣，那里的等离子体中将存在一些溅射的钨。令人感兴趣的是，在低于形成绒毛所需的温度下，从外部源沉积钨与He辐射的同时影响将在纳米气泡形成区域中产生，此外，这是否会影响先前在暴露钨之后观察到的再结晶延迟。为了研究这一过程，将与澳大利亚国立大学的Cormac Corr教授合作，对与英国原子能机构STEP(用于能源生产的球形托卡马克)计划相关的钨材料进行等离子体曝光和钨沉积。将对这些样品进行退火研究。随后将申请使用衍射技术，使用哈威尔的国家实验室设施，以测量暴露样品中的气泡大小，这将通过曼彻斯特的显微镜技术与再结晶相关联。这对于了解未来钨组件的工程性能及其适用性是至关重要的。该项目的目标是：在一定的温度和流量范围内对阶跃相关的钨材料进行氦辐照和钨沉积同时进行。使用成像和小角散射技术表征氦气泡的大小。将气泡的形成与对再结晶/其他机械性能的影响联系起来