Micro-PIXE analysis and imaging of radio-photoluminescence glass bead microdosimeters

Sub-millimeter-sized radio photoluminescence (RPL) glass bead microdosimeters using Ag and Cu activators were developed for micrometer-scale dose measurement in particle therapy. To obtain the desired size of RPL glass beads, the RPL glasses containing Ag or Cu activators were heated with carbon microparticles. The elemental composition of RPL glass beads with diameters of 400 μm were evaluated by particle-induced X-ray emission analysis using proton microbeam probe with different energy of 1.7 and 3 MeV. A nearly uniform elemental distribution was observed in both the Ag and Cu dosimeters indicating the uniform distribution of activator ions, which create the luminescence centers. These results indicate that the sub-millimeter-sized RPL glass bead dosimeters possess the basic properties required for particle dosimetry.