X-rays (OCR A Level Physics)

Describe this effect.

[2]

The attenuation (absorption) constant of the soft tissue is 0.85 cm^–1.
The intensity of the beam is 4.6 × 10³ W m^–2.
There is a small cyst 2.1 cm from the surface of the soft tissue. The cross-sectional area of the cyst normal to the beam is 3.4 × 10^–4 m².

The beam is switched on for 30 s.

Calculate the X-ray energy incident on the cyst in a period of 30 s.

energy = ....................................................... J [4]

Name a different X-ray technique that could be used to image the cyst. Explain the advantage of this technique.

[2]

X-ray photons interact with atoms.

The attenuation coefficient against lg(photon energy) graphs for simple scattering (S), photoelectric effect (PE), Compton effect (C) and pair production (PP) are shown below.

State the attenuation mechanisms for these photons.

[1]

[3]