Cubic spline representation of the two-variable cumulative distribution functions for coherent and incoherent x-ray scattering

摘要: In Monte Carlo simulation of energy-dispersive x-ray fluorescence analysers, one must account for both scattering effects and photoelectric absorption. To access the required random values differential coherent incoherent angles, two-variable cubic spline representations appropriate cumulative distribution functions are developed their use is demonstrated. this approach angle taken to be dependent variable while two independent variables energy normalized cross-sections. Cubic coefficients elements from sodium nickel have been obtained energies 1 150 keV all angles scattering. Compared with commonly used method numerically integrating tabular cross-sections produce a table subsequent interpolation, gives 90% reduction in storage space 25–80% amount computer time equal accuracy.