Radiation Effects Of Xe Ions And Gamma Rays On Both Borosilicate Glass And Fused Silica Irradiated

With the rapid development of nuclear power,the disposal of radioactive waste in China is urgent.As the primary safety barrier of high level radioactive waste,Studying the tolerance to radiation of vitrification has guiding significance for the evaluation of geological disposal.In this work,firstly,NBS2 glass and fused silica were irradiated by single energy Xe ion,and the volume change of sample was characterized by AFM.NBS1 glass was irradiated by single energy Xe ion,and the change of hardness and modulus of the sample were characterized by nanoindenter.NBS2 glass and fused silica were irradiated by multi energy Xe ion,and the change of hardness,modulus and refractive index of the sample were characterized by nanoindenter and ellipsometry,respectively.Secondly,NBS1 glass were irradiated by?-ray,and the changes of hardness,modulus and microscopic defects of the sample were characterized by nanoindenter and ultraviolet spectrophotometer,respectively.The following results were obtained:1.With irradiation of single-energied Xe ion,the volume of NBS2 glass swollen by 3.6%,the volume of fused silica collapsed by 4.7%,the hardness of NBS1 glass decreased by 37.5%,and the modulus decreased by 20%.For Xe ion multi-beam irradiation,the hardness of NBS2 glass decreased by 36%,the modulus decreased by19%,and the refractive index decreased by 2%.The hardness of fused silica has dropped by 8%,the modulus increased by 10%,and the refractive index has increased by 1%.2.With irradiation of?-ray,the concentration of non-bridge oxygen vacancy defects increased in NBS1 glass,the hardness and modulus of NBS1 glass did not change significantly with the absorbed dose of 6×10~6 Gy.By comparing the different trends of Xe ion and?-irradiated samples,it can be concluded that the decrease in hardness and modulus after heavy ion irradiation was mainly caused by the fracture of the glass network structure,and the nuclear energy deposition of heavy ions was the main cause of network structure fracture.Gamma irradiation led to microscopic defects(non-bridged oxygen vacancies etc.)in borosilicate glass.These defects were mainly produced by the breakage of bonds linked to sodium at the end of the network.Breakage of bonds linked to sodium might not affect the network structure of the borosilicate glass,Therefore,defects caused by gamma irradiation could not cause changes in hardness and modulus of the borosilicate glass.