Computation and inversion of ion spectra for neutron depth profiling of curved surfaces

Neutron depth profiling (NDP) is a nondestructive technique for determining the concentration of special isotopes within several microns of a sampleʹs surface. Previous NDP analyses, however, have been restricted to samples with plane surfaces. Here samples with curved surfaces are considered. In particular, a method for estimating the energy spectrum of ions emitted from curved surfaces is presented. Also, a robust method for inverting the NDP ion energy spectra is presented that yields accurate concentration profiles for both under- and overdetermined NDP spectra.