A versatile integrated system for thermoluminescence and optically stimulated luminescence measurements

A versatile integrated reader system for TL and OSL measurements of phosphor materials has been described for luminescence research applications. The developed integrated reader system works either in TL or OSL or TL–OSL mode. In the OSL operation, besides the conventional CW-OSL, POSL and LM-OSL modes a novel non-linear OSL (NL-OSL) method has been incorporated in the reader system. The optical stimulation unit consists of four high power LEDs fitted in four channels and optically focused on the sample. Each of the LED is capable of delivering up to 80 mW/cm2 light power at the sample position. The LEDs with peak wavelength λp ≈ 470 nm and 530 nm and Δλ ≈ 20 nm have been used for optical stimulation of the samples. A PID temperature controller has been used for generating and controlling user defined heating profiles for the TL measurements in the reader system. The reader system covers a wide dynamic dose range of 10 μGy to 103 Gy for TL/OSL measurements. The OSL grade α-Al2O3:C phosphor was used to test the reader system and investigate its impact on low dose assessment for personnel and environmental monitoring. The design concept of the reader system and the results of dose measurements are discussed.