This uses the concepts of energy developed in Stage 1, Subtopic 4.1: Energy and Stage 2, Subtopic 2.2: Motion of charged particles in electric fields; momentum developed in Stage 1, Subtopic 4.2: Momentum; and waves developed in Stage 1, Subtopics 5.1: Wave model and 5.3 Light.
- Describe the purpose of the following features of a simple X-ray tube: filament, target, high-voltage supply, evacuated tube, and a means of cooling the target.
- Describe the energy changes that occur during the production of X-rays, including the heat produced.
The three main features of the spectrum of the X-rays produced in this way are:
- a continuous range of frequencies (bremsstrahlung) due to the various proximities of the electrons with the nuclei in the target
- a maximum frequency given by where
is the potential difference across the X-ray tube
- high-intensity peaks at particular frequencies (known as characteristic X‑rays).
The intensity of X-rays is decreased (i.e. attenuated) as they pass through matter by scattering and absorption.
- Sketch a graph of the spectrum from an X-ray tube, showing the three main features of the spectrum.
- Explain the continuous range of frequencies and the maximum frequency in the spectrum of the X-rays.
- Explain the effect of manipulating the filament current or potential difference across the X-ray tube on an X-ray spectrum.
- Derive the formula for the maximum frequency,
.
- Solve problems involving the use of
.
X-rays are attenuated (reduce in intensity) as they pass through matter by scattering and absorption.
- Explain the effect of the filament current on the intensity of X-rays produced by an X-ray tube.
- Relate the attenuation of X-rays to the types of tissue through which they pass (e.g. soft tissue or bone).
- Relate the penetrating power (hardness) of X-rays required to pass through a particular type of tissue to the energy and frequency of the X-rays.
- Relate the minimum exposure time for X-ray photographs of a given hardness to the intensity of the X-rays.
Video: Features of an X-ray tube
Other videos about the X-ray device: 1 | 2 | 3
Simulation: Braking radiation
Video presentation: Factors that Affect X-ray Spectra
Simulation: X-ray Imaging