SOME EMISSION CHARACTERISTICS OF SCINTILLATING FIBERS FOR LOW ENERGY-X AND GAMMA-RAYS

The characteristics of plastic scintillating fibers (PSF) are measured for X and gamma photons in the energy range 5 keV to 1.5 MeV. It is s hown that a very thin (50 mum) slit can be recorded with an array of v ery thin fibers having 50 mum diameter so that the main interaction me chanism is photoelectric absorption, instead of Compton scattering for low energy X-rays. The optical light attenuation, global efficiency a nd energy resolution have been measured for a system composed of 1 mm diameter fibers and a photo-multiplier. An X-ray beam position detecto r is realized, using an intensified camera, allowing a 4% precision on the position. The effect of bending the fiber is also evaluated.