STUDIES ON SCINTILLATING-FIBER RESPONSE

Scintillating fibers of type Bicron BCF-12 with 2 X 2 mm(2) cross sect ion, up to 600 mm length, and PMMA cladding have been tested, in conju nction with the multi-channel photomultiplier Hamamatsu R 4760, with m inimum ionizing electrons, The impact of cladding, extramural absorber s and/or wrapping on the light attenuation and photoelectron yield is studied in detail. Fibers have been circularly bent with radii of 171 mm and arranged in two layers to bundles forming granulated scintillat or rings, Their performance in the EDDA experiment at COSY for detecti on of high energy protons revealed typically more than 9 (6) photoelec trons per fiber from bundles with (without) mirror on the rear side, g uaranteeing detection efficiencies >99% and full compatibility with co rresponding solid scintillator rings, The time resolution of 3.4 ns FW HM per fiber read out is essentially due to the R 4760.