The retention of hydrogen isotopes in W is one of the main limiting factors affecting the design and development of next-step fusion reactors, such as the international thermonuclear experimental reactor (ITER). Here, we report on D retention behavior under the steady-state He/D ion irradiations of polycrystalline W. We find that the D retention behavior in the W bulk is completely suppressed by the growth of high surface-to-volume W fuzz layer (1.1–4.0 μm thick) over the surface. Our analyses show that due to their frequent collisions in the W fuzz layer, the dose of D ions greatly decreases when they collide into the W bulk beneath the fuzz layer. The W fuzz layer with a high surface-to-volume ratio becomes an effective shield against the ion driven diffusion processes.

W中氢同位素的保留是影响下一步聚变反应堆（例如国际热核实验反应堆（ITER））设计和开发的主要限制因素之一。在这里，我们报道了在多晶W的稳态He / D离子辐照下D的保留行为。我们发现W块体中的D保留行为被高表面积W绒毛层的生长完全抑制了（在表面上厚1.1–4.0μm）。我们的分析表明，由于它们在W模糊层中的频繁碰撞，当D离子碰撞到模糊层下面的W块中时，其D离子的剂量大大降低。具有高的表面体积比的W模糊层成为有效的屏蔽离子驱动扩散过程的材料。