Potential alpha particle detection with thin poly (ether sulfone) substrates

Plastics without fluorescent-molecule doping have attracted increasing attention as radiation detection components in measurement systems to ensure safe nuclear reactors and radiation facilities. A promising candidate is poly (ether sulfone) (PES), which is resistant to environmental stress. Here, we show that transparent PES responds rapidly to alpha particles despite its amber colouration. Specifically, 1- and 5 mm-thick PES samples were exposed to an 241 Am radioactive source, and the induced PES fluorescence was acquired with a photodetector. The overall system responses were comparable to the intrinsic detector response. The averaged time profiles of the acquired fluorescence pulses for each sample exhibited leading edges that exponentially increased with rise times of 3.3 ± 0.1 ns. The falling tails exponentially decreased with decay times of 12.4 ± 0.1 ns and 12.1 ± 0.3 ns. The maximum intensity from the 1 mm-thick sample was approximately 2.4 times greater than that from the 5 mm-thick sample. This knowledge will lead to future PES applications in radiation measurements.