Nitrogen-13 is a positron-emitting radioisotope commonly used in positron emission tomography (PET) scans to assess myocardial perfusion (blood flow to the heart).
Explain the physics of positron-electron annihilation that occurs inside the patient's heart tissue and how it enables the detection system to map areas of high blood flow.
The half-life of nitrogen-13 is 9.97 minutes9.97\text{ minutes}9.97 minutes. Calculate the time ttt, in minutes, required for the activity of a prepared dose of nitrogen-13 to fall to 8.5%8.5\%8.5% of its initial activity.
Suggest why a medical imaging department utilizing nitrogen-13 must have a cyclotron located on-site or in the immediate vicinity.
90 exam-style questions on OCR A A Level Physics Nuclear and particle physics, covering The nuclear atom, Fundamental particles, Radioactivity, and Nuclear fission and fusion. Each one has a worked solution and a mark scheme showing where the marks go.