Irradiation studies of multimode optical fibres for use in ATLAS front-end links
Résumé
The radiation tolerance of three multimode optical fibres has been investigated to establish their suitability for the use in the front-end data links of the ATLAS experiment. Both gamma and neutron irradiation studies are reported. A step-index fibre with a pure silica core showed an induced attenuation of ∼0.05 dB / m at 330 kGy ( Si ) and 1×10 15 n (1 MeV Si )/ cm 2 and is suitable for use with the inner detector links which operate at 40– 80 Mb / s . A graded-index fibre with a predominantly germanium-doped core exhibits an induced attenuation of ∼0.1 dB / m at 800 Gy ( Si ) and 2×10 13 n (1 MeV Si )/ cm 2 and is suitable for the calorimeter links which operate at 1.6 Gb / s . Measurements of the dose rate dependence of the induced attenuation indicate that the attenuation in ATLAS will be lower. (Elsevier)