Deconvolution analysis improves real-time OSL of BeO ceramic

A novel method is presented to correct the non-linearity of real-time optically stimulated luminescence (rtOSL), investigated for a fibre-coupled BeO dosimetry system. The presented method applies novel kinetic modelling techniques to model the time-resolved optically stimulated luminescence, and least squares deconvolution to transform the measured rtOSL into the absorbed dose in BeO. This correction, termed the deconvolution correction, is compared against the Delta rtOSL and exponential correction methods. These rtOSL correction methods multiply the measured rtOSL by a correction function. In the..rtOSL correction, this correction function is theoretically derived, whereas the exponential correction approximates the correction function as an exponential growth with respect to time. The deconvolution correction method had a mean dose difference of 1.5%, improving upon the 4.4% and 4.1% achieved by the Delta rtOSL and exponential correction methods, respectively. These prior methods correct the measured rtOSL through multiplication with a sensitivity correction function. The deconvolution corrected responses were characterised by a 1.9% standard deviation with the expected doses, and an average root mean squared error (RMSE) of 2.0% between the corrected rtOSL signal and the modelled time-dependent accumulated dose. In comparison, the Delta rtOSL had a standard deviation of 6.4% and an average RMSE of 7.3% between the corrected rtOSL signal and the modelled time-dependent accumulated dose, while the exponential correction had a standard deviation of 5.4% and a 4.6% average RMSE between the corrected rtOSL and the time-dependent accumulated dose. To determine whether the deconvolution was feasible for real-time correction of measured rtOSL, a computational simulation of the real-time measurement and correction was performed. The maximum computation time for the deconvolution correction was 18 ms, demonstrating that the deconvolution correction is feasible for real-time correction of the rtOSL.