Performance of new Kuraray wavelength-shifting fibers with short decay time

We measure the decay time and the attenuation length of newly developed wavelength-shifting fibers, YS series from Kuraray, which have fast response. Using a 405 nm laser, the decay times of the YS-2, 4, and 6 are measured to be 3.64 ± 0.04 ns, 2.15 ± 0.03 ns, and 1.47 ± 0.02 ns, respectively, for the light injection distance of 10 cm. The decay time of Y-11 is measured to be 7.10 ± 0.09 ns using the same system. All fibers are found to have similar attenuation lengths of more than 4 meters. When combined with the plastic scintillators EJ-200 and EJ-204, the YS series have better time resolution than Y-11, with light yields of 60-100