Effect of electron beam irradiation on the microstructure, optical and electrical properties of glass resistive plate chamber detector material

The glass resistive plate chamber (RPC) detector materials were exposed to 8 MeV electron beam from 20 to 100 kGy in steps of 20 kGy. In order to study the electron beam irradiation-induced effects in glass RPC detector material, positron annihilation lifetime spectroscopy (PALS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic investigations were carried out. PALS analysis at lower electron doses indicates the increased void size with the creation of additional sites in the glass network. This is attributed to the breakage of Si–O bonds at the regular tetrahedral sites of Si–O–Si up to 40 kGy. The reduced void size at higher irradiation doses indicates the increased chemical bonding between the tetrahedral sites of Si–O–Si and hence increases the short-range order in the silica glass. These changes are complement with the XRD, FTIR results and the measured electrical conductivity. The variation of AC conductivity with frequency obeys Jonscher power law in all the electron irradiation doses at room temperature. The variation in optical band gap energy from the ultraviolet–visible (UV–Vis) spectra inferred the elimination of defects accumulation at higher irradiation doses due to the glass network close packing.