Absorption edge

(Discontinuité, arête d'absorption (Fr). Absorptionskante (Ge). Canto de absorción (Sp). край поглощения (Ru). Spigolo di assorbimento (It)

Definition

An absorption edge is a sharp discontinuity in the absorption spectrum of X-rays by an element that occurs when the energy of the photon corresponds to the energy of a shell of the atom (K, L_I, L_II, L_III, etc.).

Examples

For gallium: $\lambda_{K}$ = 1.1958 Ǻ; $\lambda_{L_{I}}$ = 9.5446 Ǻ; $\lambda_{L_{II}}$ = 10.8414 Ǻ; $\lambda_{L_{III}}$= 11.1038 Ǻ;

For arsenic: $\lambda_{K}$ = 1.0448 Ǻ; $\lambda_{L_{I}}$ = 8.1195 Ǻ; $\lambda_{L_{II}}$ = 9.1187 Ǻ; $\lambda_{L_{III}}$= 9.3617 Ǻ;

See also

Section 4.2.3 of International Tables of Crystallography, Volume C