Title :
Comparison between fast neutron and gamma irradiation of optical fibres
Author :
Henschel, H. ; Köhn, O. ; Lennartz, W. ; Metzger, S. ; Schmidt, H.U. ; Rosenkranz, J. ; Glessner, B. ; Siebert, B.R.L.
Author_Institution :
Fraunhofer-INT, Euskirchen, Germany
fDate :
6/1/1998 12:00:00 AM
Abstract :
A variety of undoped multimode step-index fibres and Ge-doped single mode and graded index fibres is irradiated by 14 MeV neutrons and 60Co gamma rays up to the same total dose. Radiation-induced loss and breaking stress are measured. The loss induced during gamma irradiation of Ge-doped fibres is about 2.5 times higher than during neutron irradiation with the same dose rate, up to a fluence of about 3×1012 cm-2 (14 MeV). This loss ratio decreases to ⩽2.0 after about 1013 cm-2 (14 MeV). Monte Carlo calculations of the dose enhancement as caused by fast recoil protons out of the H-containing acrylate coating are confirmed experimentally. 14 MeV neutron irradiation up to ⩽1013 cm -2 seems to decrease fibre breaking stress by 3-4%, whereas 60Co gamma irradiation up to the same total dose has no effect
Keywords :
Monte Carlo methods; gamma-ray effects; neutron effects; optical fibre losses; optical fibres; 1.4 MeV; Ge-doped graded index fibre; Ge-doped single mode fibre; Monte Carlo simulation; acrylate coating; breaking stress; gamma irradiation; neutron irradiation; optical fibre; radiation-induced loss; recoil protons; undoped multimode step-index fibre; Coatings; Gamma rays; Loss measurement; Monte Carlo methods; Neutrons; Optical fiber sensors; Optical fiber testing; Optical fibers; Protons; Stress;
Journal_Title :
Nuclear Science, IEEE Transactions on
