Mechanical reliability studies of optical fibres under high-dose gamma radiation

摘要

In addition to the numerous assessments presented in literature of the radiation-induced optical property changes in optical fibres, we investigate the impact of MGy dose levels on the mechanical properties of different single and multimode fibres. We compare the tensile test and two-point bending test results obtained by two different laboratories with commercially available optical fibres before and after irradiation up to 15 MGy. Our results show a significant strength reduction of about 50 % at high dose levels, relevant for particular applications in nuclear power facilities and in large nuclear physics experiments. This strength reduction seems to depend on both the coating materials and the test conditions, as suggested by the roughening of the outer glass surface of the optical fibre, observed with atomic force microscope (AFM) images.