When exposed to high-flux helium plasmas, tungsten is known to develop a surface nanostructure called tungsten fuzz. Although there exists a consensus for the general mechanisms that lead to this nanostructure, a number of questions regarding its formation have yet to be addressed. One common approach to investigate helium-tungsten interactions is thermal desorption spectroscopy (TDS), as TDS can offer insight into the trapping of helium in tungsten that ultimate drives the nanostructure growth. However, during TDS, the surface morphology of the tungsten nanostructure can change dramatically at temperatures substantially lower than those required to fully desorb the trapped helium. For a comprehensive interpretation of TDS spectra, the helium release from trapping sites should be disentangled from complications that may arise from the changing surface morphology. In this work, we characterize the effects of high-temperature annealing on the surface morphology of tungsten nanostructure during TDS. Six ITER-grade W samples were exposed to helium plasma under identical conditions (a He ion fluence ${\Phi }_i=8.6\times {10}^{24}{\mathrm{m}}^{-2},$ ion energy of 90 eV, and sample temperature of 1123 K) to generate similar surface nanostructures on each sample. Samples were then annealed at various temperatures for different durations to determine the impact of annealing temperature and duration on the surface nanostructure. During annealing, TDS spectra of the He release rate were obtained using a quadrupole mass spectrometer, yielding He release peaks near 373 K and 1123 K. Changes to the surface morphology were observed on samples annealed at temperatures as low as 1173 K, using a combination of spectroscopic ellipsometry and helium ion microscopy with focused ion beam profiling.

当暴露于高通量氦等离子体时，已知钨会形成称为钨绒的表面纳米结构。尽管对于导致这种纳米结构的一般机制已达成共识，但有关其形成的许多问题仍未解决。研究氦钨相互作用的一种常用方法是热脱附光谱法（TDS），因为TDS可以洞悉钨中的氦气捕获，从而最终驱动纳米结构的生长。但是，在TDS期间，钨纳米结构的表面形貌在显着低于完全解吸捕获的氦所需的温度下会发生巨大变化。为了全面了解TDS光谱，从捕获位置释放的氦气应与表面形态变化引起的复杂情况区分开来。在这项工作中，我们表征了TDS期间高温退火对钨纳米结构表面形态的影响。在相同条件下，将六个ITER级W样品暴露于氦等离子体（氦离子通量${\Phi }_{\mathrm{一世}}=8.6\times {10}^{24}{\mathrm{米}}^{-2}，$离子能量为90 eV，样品温度为1123 K），在每个样品上产生相似的表面纳米结构。然后将样品在各种温度下退火不同的持续时间，以确定退火温度和持续时间对表面纳米结构的影响。在退火过程中，使用四极质谱仪获得了He释放速率的TDS光谱，在373 K和1123 K附近产生了He释放峰。在低至1173 K的温度下退火的样品中，观察到表面形态的变化椭圆偏振光谱法和氦离子显微镜的聚焦离子束轮廓分析