Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (10): 100201-100201.doi: 10.11889/j.0253-3219.2017.hjs.40.100201

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS • Previous Articles     Next Articles

Low-energy helium-ions irradiation induced morphology and crystalline evolution of tungsten

LI Meng, FAN Hongyu, CUI Hejing, FAN Hongyu, WEI Lishan   

  1. School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600, China
  • Received:2017-06-21 Revised:2017-07-17 Online:2017-10-10 Published:2017-09-29
  • Supported by:

    Supported by National Natural Science Foundation of China (No.11405023), National Natural Science Foundation of Liaoning Province (No.201602189), College Students Innovation Training Project of China (No.G201612026048), "Taiyangniao" Student Research Project of Dalian Nationalities University (No.tyn2017xxx)

Abstract:

Background: Currently, tungsten has been selected as one of the best plasma-facing materials for international thermonuclear experimental reactor (ITER) due to its low hydrogen solubility, low sputtering yield, high melting point and high thermal conductivity. Purpose: In this paper, the responses of polycrystalline tungsten to low-energy helium-ions irradiation were investigated. Methods: Helium-ions irradiation was performed at 923 K with a He+ flux of 7×1021 m-2·s-1. A strong correlation between the surface morphology change and the grain orientation was confirmed from scanning electron microscope (SEM), conducive atomic force microscope (CAFM), X-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analysis. Results: SEM and CAFM measurement revel that nano-scale helium bubble formed on the surface of tungsten at earlier stage. The size and number of the formed helium bubbles increase with the increase of helium fluence until they break. Mass loss and sputtering yields analysis indicated that the surface spalling caused by the damage of helium bubble is the main format of tungsten damage. XRD and EBSD found that helium atom is shown to be not energetically favorable to dissolve, self-trap and cluster at (101) surface in comparison to (111) and (001) surface. Conclusion: The results will provide a useful reference for optimization of the plasma facing materials.

Key words: Low energy helium ions, Tungsten, Morphology, He bubble

CLC Number: 

  • TL62+7