An intrinsic fiber optic dosimeter (FOD) targeted to nuclear applications is presented. The proposed real-time dosimeter provides dose information based on the historic record over time of the effects of ionizing radiation on single- and multimode pure silica fibers, and also on PMMA plastic fibers. The effect of ⁶⁰Co gamma irradiation on optical links based on silica and plastic fibers were assessed, considering thermal environment effects over a wide range of variation of the operating parameters. Cerenkov radiation and radiation-induced absorption effects were in focus. The corresponding distortion and spectral transmission degradation were evaluated over wide range of the operating parameters. Radiation induced attenuation (RIA) has shown a spectral band dependent behaviour up to 840 Gy dose levels. The performance of different fibers was assessed against the performance of non-irradiated fibers. From the measurements of dose rate and total dose imparted by ionizing radiation in the fibers we verified that fibers with radiation resistance issues showed wavelength-dependent radiation sensitivity increasing with dose rate. Upon evaluation of correlations between the total dose, the induced loss at various dose rates and different wavelengths, it was concluded that intrinsic fiber dosimeters can be used for dose rates in the range 4 - 28 Gy/min., typical of severe radiation environments.

Date Published: 22 August 2014
PDF: 6 pages
Proc. SPIE 9286, Second International Conference on Applications of Optics and Photonics, 92864R (22 August 2014); doi: 10.1117/12.2063832

Published in SPIE Proceedings Vol. 9286:
Second International Conference on Applications of Optics and Photonics
Manuel Filipe P. C. Martins Costa; Rogério Nunes Nogueira, Editor(s)