Detection by luminescence measurements under steady irradiation

5 Detection by luminescence measurements under steady irradiation 

The radiative deactivation of excited states in polymers has found widespread application in the field of plastic scintillators. Most of the knowledge on light emission during irradiation results from research performed in the years 1950—1965 to achieve the optimum scintillation efficiency of solid polymer systems. The ionizing radiation is absorbed in a polymer, usually polystyrene, and produces excited states which are transferred with a high yield to a fluorescent solute. The theory of excitation transfer will be developed in Chapter 3. If the energy donor is P and the fluorescent solute S, competition between energy transfer to S 

The luminescence spectra of various polymers and solid model compounds induced by 1 MeV have been compared [200]. An enhanced triplet emission and the absence of fluorescence have been observed for poly(p-xylene) and poly(monochloro-p-xylene). A longer wavelength emission assigned to triplet excimer is reported. Poly(ethylenetereph-thalate) and polysulphone emit primarily from singlet and singlet excimer states. Comparison of electron and UV induced luminescence in these polymers would be very useful for the interpretation of the spectra reported. 

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