Comparison between blue and green stimulated luminescence of Al2O3:C

This paper presents a systematic comparison of OSL signals from Al2O3:C when stimulated with blue and green light. Al2O3:C detectors were irradiated with various doses and submitted to various bleaching regimes using yellow, green and blue light. Most of the investigations were carried out using LuxelTM-type detectors used in the commercial LuxelTM and InLightTM dosimetry systems (Landauer Inc.). Al2O3:C single crystals and Al2O3:C powder were also used to complement the investigations. The results show that, although blue stimulation provides faster readout times (OSL curves that decayed faster) and higher initial OSL intensity than green stimulation, blue stimulation introduced complicating factors. These include incomplete bleaching of the dosimetric trap when the Al2O3:C detectors are bleached with yellow or green light and the OSL is recorded with blue light stimulation, and an increased residual level due to stimulation of charge carriers from deep traps. The results warrant caution when using blue stimulation to measure the OSL signal from Al2O3:C detectors, particularly if the doses involved are low and the detectors have been previously exposed to high doses.