X-ray fluorescence and Moseley's law
Article No: P2524715
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. Benefits A high ranking nuclear physics experiment can be performed by students within some hours The combination of multichannel analyzer (MCA), gamma detector and high precision HV power supply leads to precise results Fundamental Rydberg's constant and Mosley's law are easily determined Tasks Calibration of the gamma-spectrometer in the low energy range, using the Ba-resonance line Cs-137 emitter (32 keV) and the gamma-line of 241 Am at 59.6 keV. Recording of the X-ray fluorescence spectra (Ka-lines) of different elements and determination of the corresponding energies. Plotting of the measured X-ray energies according to Moseley's law against (Z-1) 2 and determination of the Rydberg constant R; from the slope of the resulting lines. Learning objectives Binding energy Photoelectric eftect Shell structure of electron shells Characteristic X-ray radiation g-spectrometry X-ray spectral analysis