X-ray fluorescence and Moseley's law

The irradiation of iodine, barium (sulfat), silver and tin with soft gamma-radiations gives rise to Ka radiations characteristics of these elements. The X-ray spectra are recorded with a gamma spectrometer consisting of a scintillation counter, a pulse height analyser and a recorder. After calibration of the spectrometer, the Rydberg constant is determined from the energies of the X-ray lines, using Moseley's law.