Two parallel beams of monochromatic X-rays of the same intensity are incident on equal thicknesses of bone and fat in a patient.

The attenuation coefficient for fat is 180m⁻¹ and the attenuation coefficient for bone is 345m⁻¹. The thickness of both materials is 0.0150m.

Calculate $\frac{{{I_b}}}{{{I_f}}}$ where ${I_b}$ is the intensity of the beam leaving the bone and ${I_f}$ is the intensity of the beam leaving the fat.

Explain how fluorescent emitters are used to enhance the image formed on a photographic X-ray plate.

$\frac{{{I_b}}}{{{I_f}}} = \frac{{{e^{ - {\mu _b}x}}}}{{{e^{ - {\mu _f}x}}}}$;
=e-0.0150×165;
0.0842;
Award [3] for a bald correct answer.