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论文类型：期刊论文

发表时间：2016-04-01

发表刊物：JOURNAL OF NUCLEAR MATERIALS

收录刊物：SCIE、EI

卷号：471

页面范围：1-7

ISSN号：0022-3115

摘要：A large-power inductively coupled plasma source was designed to perform the continuous helium ions (He+) irradiations of polycrystalline tungsten (W) under International Thermonuclear Experimental Reactor (ITER) relevant conditions. He+ irradiations were performed at He+ fluxes of 2.3 x 10(21) -1.6 x 10(22)/m(2) s and He+ energies of 12-220 eV. Surface damages and microstructures of irradiated W were observed by scanning electron microscopy. This study showed the growth of nano-fuzzes with their lengths of 1.3-2.0 mm at He+ energies of > 70 eV or He+ fluxes of > 1.3 x 10(22)/m(2) s. Nanometer-sized defects or columnar microstructures were formed in W surface layer due to low-energy He+ irradiations at an elevated temperature (> 1300 K). The diffusion and coalescence of He atoms in W surface layers led to the growth and structures of nano-fuzzes. This study indicated that a reduction of He+ energy below 12-30 eV may greatly decrease the surface damage of tungsten diverter in the fusion reactor. (C) 2016 Elsevier B.V. All rights reserved.