wavelength dispersion

in X-ray emission spectroscopy
https://doi.org/10.1351/goldbook.W06661
Spatial separation of characteristic X-rays according to their wavelengths.
Source:
PAC, 1980, 52, 2541. 'Nomenclature, Symbols, Units and their Usage in Spectrochemical Analysis—IV X-Ray Emission Spectroscopy' on page 2547 (https://doi.org/10.1351/pac198052112541)