Radiation-induced loss of Rare Earth doped silica fibres

Eighteen single mode fibres doped with different Rare Earth elements are exposed to Co60 gamma radiation in order to estimate the radiation sensitivity of fibre amplifiers or fibre lasers and to find fibres with extremely high loss increase that are suited for dosimetry of low radiation levels. Induced loss measurements with varying dose rate confirmed the applicability of a simple dose rate tranformation method also to Rare Earth doped fibres. Operation of a "distributed" fibre optic radiation sensor is demonstrated at a dose rate of less than 0.1 Gy/d.