Electron beam induced microstructural changes and electrical conductivity in Bakelite polymer RPC detector material: A positron lifetime study

[摘要] In order to explore the structural modification induced electrical conductivity, samples of Bakelite RPC polymer detector materials were exposed to 8 MeV of electron beam with the irradiation dose from 20 kGy to 100 kGy in steps of 20 kGy. The microstructural changes upon electron beam irradiation have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and Fourier Transform Infrared (FTIR) Spectroscopy. Positron lifetime parameters viz., o-Ps lifetime and its intensity show chain scission at lower doses (20 kGy, 40 kGy) followed by cross-linking beyond 40 kGydue to the radical reactions. The reduction in electrical conductivity of Bakelite material beyond 60 kGy is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate doses of electron beam irradiation of Bakelite material may reduce the leakage current and hence improves the performance of the detector.

[发布机构] Department of Studies in Physics, University of Mysore, Mysore; 570006, India^1;Govt. Research Centre, Sahyadri College of Engineering and Management, Adyar, Mangalore; 575 007, India^2

[效力级别] 化学

[关键词] Detector materials;Electrical conductivity;Electron beam irradiation;Microstructural changes;Polymer detectors;Positron annihilation lifetime spectroscopy;Positron lifetime study;Structural modifications