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The relative concentration of deuterium implanted into a beryllium sample is determined by elastic peak electron spectroscopy (EPES). The method of partial intensities based on solution of the boundary value problem for the transport equation by the invariant embedding method is used for subsequent determination of the energy spectra of reflected electrons. The differential inverse inelastic mean free paths (DIIMFPs) and the differential surface excitation probability (DSEP) are retrieved using a fitting procedure based on numerous solutions of the direct problem with fitting parameters. The high efficiency of the fitting procedure is based on the technique of numerical solution of equations for the partial intensities, which combines precision and a record-high calculation speed. In the work DIIMFP and DSEP are obtained for both the surface region and for a homogeneous array in the bulk. Calculations of DIIMFP and DSEP are carried out for pure beryllium and for beryllium samples implanted with deuterium. The relative concentrations of deuterium into beryllium were determined at a different fluence. The obtained values of the relative deuterium concentrations are nD/nBe = 0.12 ± 0.02 and 0.15 ± 0.03 for an irradiation dose of 5.5 × 1021 and 20.1 × 1021 m–2, respectively. The results indicate that, in comparison with the methods used earlier, the developed method allows an order of magnitude in of the sensitivity of determining the relative hydrogen-isotope concentration in compounds to be attained. [ABSTRACT FROM AUTHOR]

Quantitative interpretation of the electron spectroscopy data requires the information on differential inverse inelastic mean free paths (DIIMFP) and differential surface excitation probabilities (DSEP). In this paper, we test an algorithm of extracting DIIMFP and DSEP from reflected electron energy loss spectra (REELS) and photo-electron spectra (PES) in which the desired functions are parametrized on the base of a classical Lorentz oscillator. Unknown parameters are found by using the fitting procedure. To account for surface excitations, the investigated samples are considered as multi-layer systems. Simulations of REELS and PES are performed by making use of the partial intensity approach. The partial intensities for the reflection function and the photo-electron density flux are computed on the base of the invariant imbedding method. Extracted DIIMFPs and DSEPs are compared with those obtained by other authors. Finally, REELS and PES spectra for Be, Mg, Al, Si, Nb and W are computed using the retrieved DIIMFPs and DSEPs, and compared with the experimental spectra. All comparisons show good agreement. [ABSTRACT FROM AUTHOR]