Effects of neutron radiation on the optical and structural properties of blue and green emitting plastic scintillators

TL;DR

This study investigates how neutron radiation affects the optical and structural properties of blue and green plastic scintillators, revealing damage and changes in fluorescence, light transmission, and molecular structure.

Contribution

It provides detailed characterization of radiation-induced damage in plastic scintillators using multiple spectroscopic techniques, highlighting structural and optical alterations.

Findings

Neutron radiation causes discoloration and damage in scintillators.

Significant structural changes observed in Raman spectra.

Decreases in fluorescence, light yield, and transmission after irradiation.

Abstract

We report on the optical and structural properties of plastic scintillators irradiated with neutron beams produced by the IBR-2 reactor of the Frank Laboratory of Neutron Physics in JINR, Dubna. Blue UPS-923A and green plastic scintillators were irradiated with neutron fluence ranging from 10$^{13}$ to 10$^{17}$ n/cm$^2$. Discolouring in the plastic scintillators was observed after irradiation. The effects of radiation damage on the optical and structural properties of the samples were characterized by conducting light yield, light transmission, light fluorescence and Raman spectroscopy studies. The results showed that neutron radiation induced damage in the material. The disappearance of the Raman peak features in green scintillators at frequencies of 1165.8, 1574.7 and 1651.2 cm$^{-1}$ revealed significant structural alterations due to neutron bombardment. Losses in fluorescence intensity, light yield and light transmission in the plastic scintillators were observed.