Scintillation Properties and ��-ray Detection Capabilities of Thin-film Plastic Scintillators

The photoluminescence and scintillation properties of thin-film plastic scintillators of 5-100 m thicknesses have been analyzed. The photoluminescence and X-ray-induced radioluminescence spectra exhibited a peak at 400-450 nm, which is typical for generic plastic scintillators. As for the radioluminescence spectra, the contribution of the short-wavelength component decreased with the increase in thickness owing to the self-absorption of scintillation photons inside the scintillators themselves. The temporal profiles of scintillation exhibited a fast decay on the order of nanoseconds. The pulse-height spectra of the scintillation detectors equipped with thin-film plastic scintillators were obtained for 5.4 MeV -rays from 241 Am to evaluate the -ray detection capabilities. Peaks were observed for thin-film plastic scintillators of 9 and 22 m thicknesses, and their light yields were estimated to be 830 and 410 photons/MeV, respectively. The dependence of pulse height spectra on film thickness indicates that selfabsorption occurs in such thin films.