Performance data of optically stimulable irradiated materials (doped alkali halides) oriented for imaging and dosimetry purposes

Performance characteristics of a doped alkali halide (KBr:In)-based imaging plate (IP) and dosemeter (D) both the devices utilizing optically stimulated luminescence (OSL) and suitable for UV-light and x-ray energy recording are described. By exploiting (silicon) photodiode array as a photodetector, the detective quantum efficiency of 0.1 for IP (KBr:In) can be achieved. A very wide dynamic range, 10¹⁰:1 for UV (6.35 eV) and 10¹¹:1 for x-ray (44 kV tube voltage) OSL recording at the spatial resolution of 1 mm ², is favorable for digital imaging and considerably improves image quality. These possibilities are illustrated by presenting available information capacities, energy consumption per bit as a function of the spatial resolution, and signal contrast ratio as a function of the input energy if using the KBr:In material with optimum characteristics (the activator concentration of 10 ¹⁷ cm^-3, the 245 nm UV-light sensitization of UV detecting, minimum concentration of Ca⁺² ions, etc.). Both the radiation dose storage is stable only up to 18 degrees Celsius and 200 s after an x-bremsstrahlung write at this temperature. When used for dose measuring, KBr-In monocrystals can be exploited for low-intensity x-ray detection and provide a possibility of the space background measuring in a second time interval.