Characterization technique of sub-millimeter scintillating fibers

The characterization of sub-millimeter scintillating optical fibers involves the measurement of the attenuation length, which is one of the main properties together with the yield and the trapping efficiency, given the use of these fibers in the design of particle detectors. Every technique considered allows for the optical coupling of the scintillating fibers to suitable photo sensors, at one or both ends. What essentially changes is the cause of scintillation light within the fibers, which comes from a UV laser or radioactive source. We have developed an alternative technique that is based on the use of cosmic rays as a uniform scintillation source. In this paper we present the results of this method compared to others obtained using standard ones.