Development of micrometer-scaled aluminum-enriched phosphate glass beads with a silver activator for real-time profile measurement of a clinical carbon beam

Real-time monitoring of clinical carbon beams from a synchrotron accelerator was accomplished by using aluminum-enriched phosphate glass with a silver activator. Build-up effects are often observed in commercially available silver-containing phosphate glass that strongly limit the use of the glass in real-time dosimetry in clinical particle therapy fields. In this study, we modified the composition of silver-containing phosphate glass by adding an additional 0.2 mol% aluminum impurity to cause broadband radioluminescence under clinical carbon beam exposure. Convenient real-time radiation monitoring was accomplished on submillimeter scales by using aluminum-enriched silver-containing phosphate glass beads. Optical fiber dosimetry using the aluminum-enriched silver-containing phosphate glass was demonstrated, and stable radioluminescence was visualized for each bunch of 290 MeV u(-1) from a synchrotron under different beam fluxes up to 3 x 10(9) particles/spill (clinical beam conditions).