Proton and photon‐induced x‐ray fluorescence intensity from a monolayer sample of complex chemical and granular composition

Abstract

A probability method is used to describe the processes of characteristic x‐ray fluorescence excitation and absorption in a heterogeneous monolayer of particles. Based on this the analytical dependence of the characteristic x‐ray peak intensity on the sizes and shape of particles, and the distribution of elements among the particles is inferred, for two kinds of spectrum excitation. Theoretical evaluations for applying boundaries of the ‘thin’ homogeneous layer model to a heterogeneous monolayer are given. The elements to be determined in unknown compositions are S, Fe and Pb.

Particle size effects in the X‐ray fluorescence analysis of monolayer samples

“…The multiple integral calculations can be simplified to routine by replacement of the inner integral as follows: = 2 C C Bl,m,nalbm(giiD)n (4) I m TI where a = h/D, h = x/h and I, m, n =0,1,2,. .…”

“…. Restricting the study to particle diameters D < 10 pm and taking into account the results of chemical analysis of airborne pollutants' one can approximate Eqn (4) with better than 8% accuracy by where B, = 3.13, B 1 = -0.546, B2 = -0.248, B 3 = --1.68 and B, = 1.49. In this case the resultant error of It in Eqn (2) never exceeds 2%.…”