Capsules that contain doped GDP layers must be characterized for dopant concentration level and uniformity. X-ray µ-fluorescence (XRF), with its unique capability to quantitatively determine concentrations of most elements simultaneously and non-destructively, and in an efficient manner, is generally the method of choice for total dopant (Z>11) concentration within ICF capsules. Dopant homogeneity (as well as concentration) within the target has been determined using Rutherford Backscatter Spectroscopy (RBS). Other methods which have provided information are SEM/EDXS; combustion analyses; mass spectroscopy and thermogravimetric analysis (TGA)