A highly sensitive programmable OSL reader for research applications

A highly sensitive programmable optical stimulation luminescence (OSL) reader system has been developed for research applications in the field of radiation dosimetry. The system hardware consists of stimulation source, light detection assembly, drawer assembly, high current driver for the stimulation light source, photon counting module and microcontroller card. The electronic hardware for the Reader is developed around P8952RD2BN microcontroller. Two Luxeon power LEDs (blue, 470 nm) placed diagonally opposite at 45 ° in the drawer assembly of the reader are used as a stimulation light source. The LED's together can generate a power of ∼ 100 mW/cm2 at the sample position with a LED current of ∼ 200 mA. The reader works in constant wave-OSL (CW-OSL), light intensity modulated-OSL (LM-OSL) and nonlinear modulated OSL(NLOSL) modes of operation. The performance of the reader system is evaluated using a-Al2O3:C OSL phosphor developed in BARC. This paper discusses the study of the Reader parameters like linearity, reproducibility, sensitivity, minimum measurable dose using the Al2O3:C phosphor using CW-OSL mode. It also discusses the photoionization cross section of the Al2O3:C sample to evaluate the linearity of stimulation light intensity. The reader also has a facility to measure the LED light intensity at the sample position. The LM-OSL curves are plotted photoionization cross-section of various phosphor materials was evaluated. Such low cost reader systems are very useful for radiation dosimetry and material research. (author)