A high quality x-ray spectrum image of a 3.3 μm diameter sphere of K411 glass resting on a copper substrate was collected at 25 keV. The same sample configuration was modeled using the NISTMonte Monte Carlo simulation of electron and x-ray transport as is integrated into the quantiative x-ray microanalysis software package DTSA-II. The distribution of measured and simulated x-ray intensity compare favorably for all the major lines present in the spectra. The simulation is further examined to investigate the influence of angle-of-incidence, sample thickness and sample diameter on the generated and measured x-ray intensity. The distribution of generated x-rays is seen to deviate significantly from a naive model which assumes that the distribution of generated x-rays is similar to bulk within the volume they share in common. It is demonstrated that the angle at which the electron beam strikes the sample has non-negligible consequences. It is also demonstrated that within the volume that the bulk and particle share in common that a significant fraction of the x-rays are generated by electrons which have exited and later reentered the particle volume. This occurs both on the bottom and on the sides of the particle. Any general model of x-ray generation in particles must take into account the lateral spread of the scattered electron beam. 1 of
Citation: Microscopy and Microanalysis
Pub Type: Journals
"x-ray", "microanalysis", "particles", "quantification"