Fibre irradiation under air, dry air, argon and nitrogen at low dose rates

We have irradiated samples of different commercial plastic scintillating fibres in several atmospheres at dose rates of 1.4 and 5.8 Krad/h up to 500 Krad total dose. A preliminary data analysis indicates that the loss in transmission immediately after irradiation is bigger in fibres irradiated in inert gases (argon and nitrogen) than in fibres irradiated in air and dry air. A week after irradiation all fibres had largely recovered and their light transmission depended on the type of fibre, but not on the atmosphere during irradiation nor on dose rate. © 1993.