Studies on thermally induced microstructural modifications and electrical conductivity in glass RPC detector materials

Abstract Asahi and Saint Gobain float glass Resistive Plate Chamber (RPC) detector materials are subjected to isochronal annealing treatment. To explore the temperature induced microstructural modifications in glass RPC detector materials, Positron annihilation lifetime spectroscopy (PALS), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic investigations were performed. The positron lifetime parameters viz., o-Ps lifetime (τ3) and void size (Vf) increased significantly due to thermal expansion of Si O Si bonds in the regular tetrahedral structure of glass network. The significant increase in the void size of glass RPCs above 150 °C annealing temperature is attributed to the thermal vibrations of Si O Si bonds. The temperature induced electrical conductivity and activation energy is correlated with the positron lifetime parameters in both the float glasses. The thermally induced structural changes at higher annealing temperature are more in Saint Gobain glass than Asahi float glasses.