Principle

Various alloyed materials are subjected to polychromatic X-rays. The energy of the resulting fluorescence radiation is analysed with the aid of a semiconductor detector and a multichannel analyser. The energy of the corresponding characteristic X-ray fluorescence lines is determined. In order to determine the concentration of the alloy constituents, the intensity of their respective fluorescence signals is compared to that of the pure elements.

Tasks

1. Calibration of the semiconductor energy detector with the aid of the characteristic radiation of the tungsten X-ray tube.
2. Recording of the fluorescence spectra that are produced by the alloyed samples.
3. Recording of the fluorescence spectra that are produced by the pure metals.
4. Determination of the energy values of the corresponding fluorescence lines.
5. Calculation of the concentration levels of the alloy constituents.

Learning objectives

• Bremsstrahlung
• Characteristic X-radiation
• Energy levels
• Fluorescent yield
• Auger effect
• Coherent and incoherent photon scattering
• Absorption of X-rays
• Edge absorption
• Matrix effects
• Semiconductor energy detectors
• Multichannel analysers