Irradiation Effects on the Retention of Hydrogen in Al2O3**Supported by the National Natural Science Foundation of China under Grant Nos 91426304 and 91226202, and the National Magnetic Confinement Fusion Energy Research Project under Grant No 2015GB113000.

Abstract

Substantial defects are produced in Al2O3 by 4 MeV Au ion irradiation with a fluence of 4.4 × 1015 cm−2. Rutherford backscattering spectrometry/channeling and cross-sectional transmission electron microscopy methods are used to investigate the irradiation damage. The 190 keV H ions with a fluence of 1 × 1017 cm−2 are used for implanting pristine and Au ion irradiated Al2O3 to explore the irradiation damage effects on the hydrogen retention in Al2O3. The time-of-flight secondary ion mass spectrometry method is used to obtain the single hydrogen depth profile and ions mass spectra (IMS), in which we find that implanted hydrogens interacted with defects produced by Au ion irradiation. In IMS, we also obtain the hydrogen retention at a certain depth. Comparing the hydrogen retention in different Al2O3 samples, it is concluded that the irradiation damage improves the tritium permeation resistance property of Al2O3 under given conditions. This result means that Al2O3 may strengthen its property of reducing tritium permeation under the harsh irradiation environment in fusion reactors.