@article{guo_gardner_mayo_2005, title={A study of the real-time deconvolution of digitized waveforms with pulse pile up for digital radiation spectroscopy}, volume={544}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2004.12.036}, abstractNote={Two new real-time approaches have been developed and compared to the least-squares fit approach for the deconvolution of experimental waveforms with pile-up pulses. The single pulse shape chosen is typical for scintillators such as LSO and NaI(Tl). Simulated waveforms with pulse pile up were also generated and deconvolved to compare these three different approaches under cases where the single pulse component has a constant shape and the digitization error dominates. The effects of temporal separation and amplitude ratio between pile-up component pulses were also investigated and statistical tests were applied to quantify the consistency of deconvolution results for each case. Monte Carlo simulation demonstrated that applications of these pile-up deconvolution techniques to radiation spectroscopy are effective in extending the counting-rate range while preserving energy resolution for scintillation detectors.}, number={3}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Guo, WJ and Gardner, RP and Mayo, CW}, year={2005}, month={Jun}, pages={668–678} }
 @article{gardner_guo_2005, title={Development of a Monte Carlo - Library Least-Squares code package for the EDXRF inverse problem}, volume={20}, ISSN={["1945-7413"]}, DOI={10.1154/1.1913722}, abstractNote={The Monte Carlo—Library Least-Squares (MCLLS) approach has now been developed, implemented, and tested for solving the inverse problem of EDXRF sample analysis. It consists of a linear library least-squares code and a comprehensive Monte Carlo code named CEARXRF that is capable of calculating the unknown sample spectrum, all the elemental library spectra in the sample, and the differential operators for each library spectrum with respect to each element. Two codes with graphical user interface have been designed to implement the MCLLS approach and benchmark results are presented for the two stainless steel samples; SS304 and SS316. The results are accurate, the system is easy to use, and all indications are that this approach will be very useful for the EDXRF practitioner.}, number={2}, journal={POWDER DIFFRACTION}, author={Gardner, RP and Guo, W}, year={2005}, month={Jun}, pages={146–152} }
 @article{guo_gardner_metwally_2004, title={Preliminary studies on K and L coincidence spectroscopy for optimizing the in vivo XRF measurement of lead in bone}, volume={213}, ISSN={["0168-583X"]}, DOI={10.1016/S0168-583X(03)01674-4}, abstractNote={Previous studies treated the optimal combined K and L XRF system which consists of a Cd-109 point source, a low energy Ge detector (LEGe) and a Si(Li) detector. The Monte-Carlo library least-squares (MCLLS) approach and differential operator approach were treated separately. In this work, an approach for combining the MCLLS approach with the differential operator approach (MCDOLLS) is presented and an optimal configuration for coincidence spectroscopy of K and L X-rays is proposed based on preliminary experimental data.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS}, author={Guo, WJ and Gardner, RP and Metwally, WA}, year={2004}, month={Jan}, pages={574–578} }
 @article{guo_lee_gardner_2004, title={The Monte Carlo approach MCPUT for correcting pile-up distorted pulse-height spectra}, volume={531}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2004.05.089}, abstractNote={Pulse pile-up distortion is a common problem for radiation spectroscopy measurements involving high counting rates. The Monte Carlo pile-up to true approach (MCPUT) is proposed and benchmarked in this article for correcting pile-up distorted pulse-height spectra to true spectra. In previous work, a Monte Carlo approach was used for predicting the pile-up distorted pulse-height spectra for high counting-rate measurements (“the forward calculation”). The present work improves the previous simulation by employing a better ADC dead-time model. Based on this improved “forward calculation”, the MCPUT approach introduces an iterative procedure for correcting pile-up distortions. Experiments with an Fe-55 source and a Si(Li) detector are used for benchmarking purposes. The MCPUT corrected spectrum for the high counting-rate measurement shows excellent agreement with the measured true spectrum at low counting rate with reduced chi-square as the quantitative measure. The approach is also efficient, as accurate calculations are possible in a few minutes.}, number={3}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Guo, WJ and Lee, SH and Gardner, RP}, year={2004}, month={Oct}, pages={520–529} }