On the use of ionization cross sections in analytical electron microscopy

There are two approaches to the utilization of the ionization cross section, Q, for use in the determination of kappa AB factors for quantitative microanalysis in the analytical electron microscope. The first approach is to interpolate a value of Q from experimentally determined kappa AB factors at a fixed accelerating voltage (kV). The second approach uses a theoretical parameterization of Q generated by fitting the fundamental Bethe expression to selected experimental values of Q over a wide range of kV. This paper discusses the relative merits of the two approaches.