SOFTI: intermediate results of long term irradiation and thermal ageing tests of photonic components

This paper presents the first results of long term experiments conducted within the SOFTI (Study of Optical Fibres and components under Thermal ageing and Irradiation) project. This on-going 6-years study is intended to determine the effects of ageing on the behaviour of optical fibres and their fibre-end components submitted to harsh environments, with respect to the safety of nuclear facilities. The test program consists of irradiations at low dose rates with different thermal constraints and spool radius. After completion, these tests will enable us to write a guideline for qualification procedures related to future fibre-optic systems, for their applications in nuclear facilities. The observations of these first results show a clear dependence of the radius of curvature for the radiation induced loss. To our knowledge, it is the first time that this was experimentally verified for a radius of curvature superior to 6 cm.