Monochromatisation of copper X-rays

Principle

The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils.

Tasks

1. Record the intensity of the X-rays emitted by the copper anode as a function of the Bragg angle, using a LiF monocrystal as analyzer. The energy values of the characteristic copper lines are to be calculated.
2. Use the LiF monocrystal to filter out a characteristic line and record the appertaining monochromatization graphically.
3. Record  the intensity of the X-rays emitted by the copper anode as a function of the Bragg angle, using a LiF monocrystal as analyzer and a nickel filter.

Learning objectives

• Bremsstrahlung
• characteristic radiation
• energy levels
• absorption
• absorption edges
• interference
• diffraction
• Bragg scattering.