Measurement of light attenuation angular dependence in a double-clad wavelength shifting fibre Y11(200)MS

Measurements of attenuation in double-clad WLS fibre Y11(200)MS were carried out using a blue LED source and angular positioning of the photodetector. Data obtained for the external polar angle range up to 60 ∘ allowed the separation of the bulk attenuation and reflection inefficiencies for the fibre core and core–clad1 interface as well as for the clad1–clad2 interface. of this type have been used for the optical instrumentation of the Tile Hadron Calorimeter of the ATLAS detector.