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.
Absorption material, lead
Gamma detector
High-voltage connecting cable
PHYWE Multichannel Analyser (MCA)
measure Software multi channel analyser
Barium sulphate 500 g
Iodine resublimed 25
Silver foil, 150 x150 x 0.1 mm, 25 g
Tin-II chloride 250 g
Universal clamp
Plastic sack, flat, DIN A5, 100pc
Support base DEMO
Support rod, stainless steel, l = 250 mm, d = 10 mm
Support rod with hole, stainless steel, 10 cm
Spring balance holder
Alligator clips, bare, 10 pcs
Screened cable, BNC, l = 750 mm
Radioactive source Am-241, 370 kBq
Radioactive source Cs-137, 37 kBq
PHYWE high precision power supply 1.5 kV DC
Right angle clamp expert
- 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.
- Binding energy
- Photoelectric eftect
- Shell structure of electron shells
- Characteristic X-ray radiation
- g-spectrometry
- X-ray spectral analysis