Retention and desorption behavior of helium in oxidized V–4Cr–4Ti alloy

Abstract Retention and desorption behaviors of helium in oxidized and non-oxidized V–4Cr–4Ti alloy samples were investigated after helium ion irradiation at room temperature using a thermal desorption spectroscopy. The ion energy and fluence were 5 keV and (0.5–10) × 10 21  He/m 2 , respectively. An oxidized layer with a thickness of 100 nm was prepared by thermal oxidation. The surface density of blisters produced by helium ion irradiation in the oxidized sample was lower than that in the non-oxidized one. The helium desorption behavior depended significantly on the fluence. In the lower fluence regime, the retained helium desorbed mainly at around 1300 K in both samples. As fluence increased, several desorption peaks appeared in the low temperature region in both samples. However, the peak temperatures were different. The amount of helium retained in the oxidized sample was lower than that in the non-oxidized sample.