(a)[3]
The X-ray tube forms an image with a current of $0.40\,\text{A}$ applied for $20\,\text{ms}$. Tungsten has a specific heat capacity of $130\,\text{J kg}^{-1}\text{K}^{-1}$. Find the temperature rise $\Delta T$ of the tungsten target.
(b)[2]
The linear attenuation coefficient of the X-ray photons in muscle is $0.22\,\text{cm}^{-1}$. Find the thickness $t$ of muscle needed to absorb $80\%$ of the incident X-ray intensity.
(c)[2]
Table 10.1 gives the linear attenuation coefficient $\mu$ for the X-ray photons in different tissues. Two X-ray images are made, one using equal thicknesses of bone and muscle and the other using equal thicknesses of blood and muscle. Explain why one of these images shows good contrast, whereas the other does not.