70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-workin...70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-working and Ti-adding from room temper- ature to 802℃. The created swelling is microscopically examined by the positron annihilation lifetime technique. A radiation swelling peak is observed at 580℃ and the corresponding void has an average diameter of 0.7 um which is hardly probed by macroscopic methods.展开更多
In this paper, the damage to methyl silicone rubber induced by irradiation with protons of 150 keV energy wasstudied. The surface morphology, tensile strength, Shore hardness, cross-linking density and glass transitio...In this paper, the damage to methyl silicone rubber induced by irradiation with protons of 150 keV energy wasstudied. The surface morphology, tensile strength, Shore hardness, cross-linking density and glass transition temperaturewere examined. Positron annihilation lifetime spectrum analysis (PALS) was perfomed to reveal the damage mechanisms ofthe rubber. The results showed that tensile strength and Shore hardness of the rubber increased first and then decreased withincreasing irradiation fluence. The PALS characteristics τ_3 and I_3, as well as the free volume V_f, decreased with increasingirradiation fluence up to 10^(15) cm^(-2), and then increased slowly. It indicates that proton irradiation causes a decrease of freevolume in the methyl silicone rubber when the fluence is less than 10^(15)cm^(-2), while the free volume increases when thefluence is greater than 10^(15)cm^(-2). The results on cross-linking density indicate that the cross-linking induced by protonirradiation is dominant at smaller proton fluences, increasing the tensile strength and Shore hardness of the rubber, while thedegradation of rubber dominates at greater fluence, leading to a decrease of tensile strength and Shore hardness.展开更多
Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was...Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.展开更多
基金The project supported by the National Natural Science Foundation of China
文摘70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-working and Ti-adding from room temper- ature to 802℃. The created swelling is microscopically examined by the positron annihilation lifetime technique. A radiation swelling peak is observed at 580℃ and the corresponding void has an average diameter of 0.7 um which is hardly probed by macroscopic methods.
文摘In this paper, the damage to methyl silicone rubber induced by irradiation with protons of 150 keV energy wasstudied. The surface morphology, tensile strength, Shore hardness, cross-linking density and glass transition temperaturewere examined. Positron annihilation lifetime spectrum analysis (PALS) was perfomed to reveal the damage mechanisms ofthe rubber. The results showed that tensile strength and Shore hardness of the rubber increased first and then decreased withincreasing irradiation fluence. The PALS characteristics τ_3 and I_3, as well as the free volume V_f, decreased with increasingirradiation fluence up to 10^(15) cm^(-2), and then increased slowly. It indicates that proton irradiation causes a decrease of freevolume in the methyl silicone rubber when the fluence is less than 10^(15)cm^(-2), while the free volume increases when thefluence is greater than 10^(15)cm^(-2). The results on cross-linking density indicate that the cross-linking induced by protonirradiation is dominant at smaller proton fluences, increasing the tensile strength and Shore hardness of the rubber, while thedegradation of rubber dominates at greater fluence, leading to a decrease of tensile strength and Shore hardness.
基金Supported by International Atomic Energy Agency under Contract No.10637
文摘Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.
