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 Luxel?-type detectors used in the commercial Luxel? and InLight? 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.