The ALCHEMI technique for determining the site distribution fi of an impurity element x on host element lattice sites i is well known: Changes in x-ray emission from host atoms i and impurity x with crystal orientation ARE monitored under strong planar or axial diffraction conditions, and fi derived via a ratio method. However analysis involving count ratios (and ratios of ratios) leads to severe error amplification. Neglect of delocalization leads to further error. To overcome these inherent errors in the standard ALCHEMI method, we make the single assumption that the impurity count Nx may be written as a linear combination of the host atom counts Ni, i.e.where the coefficients αi and their errors are determined by multivariate analysis. For m separate EDX spectra and fitted parameters αi (i = 1 to v), the criterion v ≤ m must be satisfied for m - v degrees of freedom.
Spectral sensor error analysis for measuring x-ray radiation drive using the DANTE diagnostic toward inertial confinement fusion experiments