Abstract
The influence of atmospheric oxygen on the efficiency of the PRESAGE (R) dosimeter was investigated. Batches of PRESAGE (R) and reporting system solution were deoxygenated using nitrogen and compared to similar batches that were exposed to atmospheric oxygen during fabrication. The overall results show little influence of oxygen on the characteristics of PRESAGE (R) with the radical initiator oxidizing the leucomalachite green in the presence of oxygen. However, when deoxygenating the reporting system the sensitivity to radiation dose increased by 30% compared to the non-deoxygenated system. A slight improvement in sensitivity (5%) was achieved by deoxygenating the PRESAGE (R) precursors prior to casting. The results suggest that the solid polyurethane matrix is not permeable to atmospheric oxygen. In addition, there were no observed changes in the dose linearity, absorption spectrum and post-response photofading characteristics of PRESAGE (R) under the conditions investigated.