Results of a low dose rate irradiation of selected plastic scintillating fibers

A series of high-dose-rate (20-kGy/h) and low-dose-rate (<10-Gy/h) irradiations of a large sample of plastic scintillating fibers (1-mm phi , 150-cm length) has been completed. Measurements of the transmission characteristics of the fibers have been completed. The transmission measurements show striking features: (1) those fibers irradiated slowly in air (i.e. in the presence of oxygen) suffer the greatest level of damage, while (2) the fibers irradiated rapidly, and then allowed to recover, display the least amount of damage, and (3) fibers irradiated slowly in argon display a level of damage intermediate between the other two. One fiber, the green-emitting SCSF-Y8, is the only exception, and shows no difference in the level of damage observed in the three modes of irradiation.<
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