@article{gardner_guo_ao_dobbs_1997, title={Black box radiation gauges and analyzers: Dream or reality?}, volume={48}, ISSN={["0969-8043"]}, DOI={10.1016/S0969-8043(97)00120-6}, abstractNote={This paper describes our attempts to make radiation gauges and analyzers operate in more of a ‘block box’ manner — being more independent of or at least more insensitive to changes in such things as sample composition and position. Our overall approach relies heavily on Monte Carlo simulation and that is discussed first in relation to radiation gauge and analyzer design and usage. Then the principles and applications of radiation gauges and analyzers including the Measurement Chi-Square and Monte Carlo Library Least-Squares, respectively, are treated. Finally future work in this area is discussed.}, number={10-12}, journal={APPLIED RADIATION AND ISOTOPES}, author={Gardner, RP and Guo, P and Ao, Q and Dobbs, CL}, year={1997}, pages={1273–1288} }
 @article{ao_lee_gardner_1997, title={Development of the specific purpose Monte Carlo code CEARXRF for the design and use of in vivo X-ray fluorescence analysis systems for lead in bone}, volume={48}, ISSN={["0969-8043"]}, DOI={10.1016/S0969-8043(97)00136-X}, abstractNote={X-ray fluorescence (XRF) systems have been increasingly used for in vivo toxic trace-element analysis in the human body, such as lead in the tibia. Monte Carlo simulation can provide an efficient and flexible method for designing and using in vivo XRF systems. The Monte Carlo code CEARXRF has been developed specifically to simulate the complete pulse height spectrum of energy-dispersive XRF systems. This code is capable of tracking photons in a general geometry and modelling all of the physics of photon interactions in the energy range 1-150 keV for elements Z = 1-94, including primary and higher degree excitations of K and L XRF, the Doppler broadening of Compton-scattered photon energies, and the polarization effects in low-energy photon scatterings. The scattering background for minimum detectable concentration (MDC) analysis may be simulated more accurately by taking into account Doppler broadening in the distribution of the Compton-scattered photon energy due to electron-binding effects. The use of polarized excitation photons has been shown to be important in producing a low scattering background and good measurement sensitivity. The code has two very unique and important features: (1) complete composition and density correlated sampling that is extremely useful for studying measurement sensitivity to small changes in sample composition and density; and (2) Monte Carlo library spectra calculation for the determination of elemental amounts by the Monte Carlo-Library Least-Squares (MCLLS) method. The capability of CEARXRF to aid the design and optimization of in vivo XRF analysis has been verified by modelling hypothesized lead K and L XRF measurement systems.}, number={10-12}, journal={APPLIED RADIATION AND ISOTOPES}, author={Ao, Q and Lee, SH and Gardner, RP}, year={1997}, pages={1403–1412} }
 @article{ao_lee_gardner_1997, title={Optimization of in vivo X-ray fluorescence analysis methods for bone lead by simulation with the Monte Carlo code CEARXRF}, volume={48}, ISSN={["0969-8043"]}, DOI={10.1016/S0969-8043(97)00137-1}, abstractNote={In the design of X-ray fluorescence (XRF) systems for in vivo measurements of lead in human bone, the most important considerations are the minimum detectable concentration (MDC), and accuracy and precision. Possible design optimizations can be investigated much more easily and economically by Monte Carlo simulation than by experiment. The specific purpose Monte Carlo code CEARXRF has been used in the present study for: (1) improving the MDC of a hypothesized in vivo 109Cd source-based KXRF system and a 109Cd source or X-ray tube source-based LXRF system by investigating the effects of source polarization and source-bone-detector geometry modification on reducing the scattering background, and (2) investigating the effects of sample variables, such as overlying skin thickness on the MDC and the lead XRF intensity precision. In addition, the feasibility of the Monte Carlo-Library Least-Squares (MCLLS) approach has been investigated in a preliminary fashion for 109Cd-based KXRF spectroscopy analysis.}, number={10-12}, journal={APPLIED RADIATION AND ISOTOPES}, author={Ao, Q and Lee, SH and Gardner, RP}, year={1997}, pages={1413–1423} }
 @article{guo_ao_gardner_1997, title={Spectral gamma-ray log interpretation algorithms using the Monte Carlo multiply scattered components approach}, volume={48}, ISSN={["0969-8043"]}, DOI={10.1016/S0969-8043(97)00132-2}, abstractNote={Abstract New algorithms for spectral gamma-ray log interpretation have been developed on the basis of a novel approach originally developed for natural gamma-ray log interpretation using the lithology-independent Monte Carlo multiply scattered components (MCMSC) approach. With separation of density and composition effects, the new algorithms have fewer parameters and have been designed for both natural gamma-ray and gamma-gamma litho-density logs.}, number={10-12}, journal={APPLIED RADIATION AND ISOTOPES}, author={Guo, P and Ao, Q and Gardner, RP}, year={1997}, pages={1373–1383} }