Deconvoluting a Pb in zircon profile from [48].

(a) shows an apparent Pb Lα profile between Pb-doped and Pb-free zircon, generated by CASINO [20], using an incident beam at 25 kV with a nominal 2 μm diameter. From the fit, σ = 693 nm, hence FWHM = 1633 nm. However, because [48] analysed a section 30° from normal to the interface, the relevant FWHM is 1633/~2 ≈ 816 nm. (b) shows the [48] EPMA profile, deconvoluted. Convolution has an effect of <0.01 log₁₀D units in this case.