Figure 5
Examples of removal of the elastic peak from the phonon excitation probability density S(E) by interpolation of the signal at the left and right of the elastic peak. (a) Olivine (Dauphas et al., 2014). (b) Fe3+-rich rhyolite glass (Dauphas et al., 2014). (c) Fe2+-rich basalt glass (Dauphas et al., 2014). (d) Goethite (Dauphas et al., 2012; Blanchard et al., 2014). The user moves the red sliders to define the energy range used for the interpolation (red and black vertical markers E1, E2, −E1, −E2). The blue curve shows the interpolated function using equation (4). In some cases (most minerals) the interpolation is straighforward but in others (e.g. glasses) the range available to define the interpolation is narrow. The spectrum between −E1 and E1 (elastic peak) is replaced by the interpolated function before further processing. The values of S(E) near zero, at or near the elastic peak, are artifacts from the deconvolution algorithm (the black curve is the spectrum after deconvolution of the resolution function). |