Color changes in irradiated plastics and their application to γ-radiation dosimetry

A thorough investigation of the response of colored PMMA sheets to y-radiation has been carried out using uv-visible spectroscopy. Linear reproducible relationships between absorption intensity and dosage occurred for blue PMMA samples. Increasing dosage reduced the intensity of some bands and increased that of others forming a sharp isospestic point. This indicates an equilibrium transition state between two absorption species, namely blue-yellow, which can be explained as structural changes in the polymeric and dye molecules. Linearity, reproductibility of results and storage stability of blue PMMA samples suggest their application as efficient plastic dosemeters.