Absorption edge

(French: Discontinuité, arête d'absorption. German: Absorptionskante. Spanish: Canto de absorción. Russian: край поглощения).

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:

[math]\lambda_{K}[/math] = 1.1958 Ǻ; [math]\lambda_{L_{I}}[/math] = 9.5446 Ǻ; [math]\lambda_{L_{II}}[/math] = 10.8414 Ǻ; [math]\lambda_{L_{III}}[/math]= 11.1038 Ǻ;

For arsenic:

[math]\lambda_{K}[/math] = 1.0448 Ǻ; [math]\lambda_{L_{I}}[/math] = 8.1195 Ǻ; [math]\lambda_{L_{II}}[/math] = 9.1187 Ǻ; [math]\lambda_{L_{III}}[/math]= 9.3617 Ǻ;

See also

Section 4.2.3 of International Tables of Crystallography, Volume C