Formalism for thin-target XRF

To convert the peak intensities into the elemental mass concentrations, a fundamental parameter approach is used. According to this approach, the intensity Nij of the fluorescent X-ray line i of the jth element, is related to the mass ruj of the element present in the sample 

The absorption correction term (3, for intermediate thick sample, is given by 

Here M is the total mass of the sample, ii( J-/) is the mass absorption coefficient at incident (fluorescent) energy and is the grazing angle of incidence (fluorescence). 

The self-absorption effects become negligible if the targets are very thin and of uniform thickness, The elemental concentration mj(gcm ) in various samples can be determined using the expression  

The variation of total attenuation cross-section as a function of 

---