Dosimetry of ionizing radiations by luminescence methods

Various types of luminescence processes can be generated in insulating materials by their interaction with ionizing radiation beams. In suitable systems, the luminescence intensity is proportional to dose or to dose-rate, and therefore it can be exploited for dosimetry purposes. Luminescence signals can have a prompt or delayed character and, accordingly, they can be used for on-line or for post-radiation dose monitoring. A brief description of the physical processes governing the interaction of ionizing radiation with matter and leading to prompt scintillation or to free carrier trapping at lattice defects will be shown. Then, the fundamental principles of post-radiation dosimetry based on techniques like thermoluminescence (TL), optically stimulated luminescence (OSL) and radio-photoluminescence (RPL) will be reviewed with particular emphasis on material requirements. Finally, the characteristics of remote on-line dosimetry systems based on scintillating glass optical fibers will be discussed. Their use for a prompt and efficient monitoring of remote radiation fields will be described together with the possible strategies to solve technological problems like the separation between scintillation and Cerenkov light, and the occurrence of radiation-induced luminescence sensitivity changes.