REFLECTION LOSSES IN POLYSTYRENE FIBERS

The reflection losses, which occur during light guidance through polystyrene fibres of 30-mu-m diameter at their core-cladding interface, have been determined in order to evaluate their contribution to the total light attenuation of scintillating fibres. For the deviation (1 - q) of the reflection coefficient q from unity we obtained: 6 x 10(-5) (at 458 nm), 5.36 x 10(-5) (at 514 nm) and 5 x 10(-5) (at 633 nm). In addition, we found light losses in the polystyrene core, which we attribute to Rayleigh scattering on submicron density variations in polystyrene. The resulting scattering lengths are: 3.6 m (at 420 nm) and 9.5 m (at 530 nm).