'A' Level Medical Option Questions - X-Rays
The diagram shows a fluoroscopic image intensifier.
(a) State the purpose of:
(i) the fluorescent screen, A,
It converts X rays to visible photons
(ii) the photocathode,
It converts photons to emission of electrons
(iii) the anodes,
They increases the kinetic energy of electrons travelling from cathode to anode and they also focus the rays of electrons to produce a faithful image
(iv) the fluorescent screen, B.
It converts (increased) electron energy into light photons
(b) Give one example of a medical application for which an image intensifier might be used. Explain why the use of an image intensifier is required.
It might be used for a dynamic process - such as fluid flow It cuts the radiation dose whilst still providing good image [or allows multiple or continuous use of X rays]
(Total 6 marks)