Splitting techniques for Monte Carlo simulations of secondary fluorescence in EPMA

PETACCIA, MAURICIO; CASTELLANO, GUSTAVO

Tandil

Congreso; 99a Reunión Anual de la Asociación de Física Argentina; 2014

Universidad Nacional del Centro de la Provincia de Buenos Aires

Quantitative Electron Probe Microanalysis (EPMA) is based on characteristic X-ray detection due to electron impact. Some of these photons may be generated by other photons capable of exciting the element under study and the detector can not determine its origin. This secondary fluorescence events are very unlikely, and, although it can not be measured, it could be critical for trace element analysis for example. The aim of Monte Carlo simulation of radiation transport is to generate random collisions to reproduce particle trajectories and it becomes a determinant tool in the study of secondary fluorescence. The routine package PENELOPE allows the use of the Splitting Technique, which consists in replacing a particle of interest by N copies of this particle in exactly the same conditions, raising in this way the statistics associated with a particular event. N must be high enough to reduce the variance but not so big to distort the results. Our final objective is the study of the secondary fluorescence enhancement in EPMA using the alternatives offered by PENELOPE. To this aim we studied the influence of the choice for the splitting factor N in the standard deviation in secondary fluorescence intensities for a Fe01Ni99 alloy and accelerating voltage of 10keV, 15keV and 20keV.