Fluorescence pulses derived from thin poly (ethylene terephthalate) in response to charged particles

Poly (ethylene terephthalate) (PET) is an abundant polyester used on a worldwide scale. Its versatility extends to radiation detection and measurements. Here, we show the attractive behaviours of thin PET in response to charged particles. The PET samples with 1-mm, 3-mm, 5-mm thicknesses were exposed to alpha particles from an 241Am radioactive source and beta particles from a 90Sr radioactive source and were monitored with a commercial photodetector. The acquired pulses were characterised by time profiles. Depending on the sample thickness, the averaged time profiles for each particle type were equivalent with regard to shape, despite variations in intensity. For the 1-mm-thick sample, the falling tails predominately followed an exponential decrease with decay times of 13.8 0.5 ns for alpha particles and 10.7 0.3 ns for beta particles. The leading edges increased exponentially, with rise times of 3.3 0.1 ns for both particle types. These results revealed that the PET fluorescence induced by charged particles leads to sharp pulses comparable to rapid detector responses. This knowledge opens up potential applications of thin PET to pulse measurements in the presence of charged particles.