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How do I calculate the wavelengths of electromagnetic radiation?

In this article:

  • Electromagnetic radiation, including X-rays, is characterized by its wavelength (λ), which determines its energy and interaction with matter in industrial inspection.
  • Wavelength is calculated using the formula:
    • λ=cfλ=fc​
    • where λλ is the wavelength, cc is the speed of light, and ff is the frequency of the radiation.
  • X-rays are generated in X-ray tubes when high-energy electrons strike a metal target, producing short-wavelength radiation ideal for non-destructive testing (NDT).
  • Wavelengths are expressed in various units such as meters (m), nanometers (nm), micrometers (μm), and Ångströms (Å), depending on the application and precision required.
  • Understanding and calculating wavelengths is essential for optimizing imaging resolution, penetration depth, and material contrast in industrial radiography and CT systems.

In 1895 the physicist Wilhelm Conrad Röntgen discovered a new kind of radiation, which he called X-rays. The rays were generated when high energy electrons were suddenly stopped by striking a metal target inside a vacuum tube – the X-ray tube. It was subsequently shown that X-rays are an electromagnetic radiation, just like light, heat and radiowaves.

 

Wavelengths of electromagnetic radiation

The wavelength lambda (λ) of electromagnetic radiation is expressed in m, cm, mm, micrometer (μm), nanometer (nm) and Ångstrom (1 Å = 0.1 nm).

 

What is an X-ray tube?

Table 1.2. Overview of wavelength, energy and type of electromagnetic radiation