| Date | May 2017 | Marks available | 3 | Reference code | 17M.3.HL.TZ2.16 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Discuss | Question number | 16 | Adapted from | N/A |
Question
In nuclear magnetic resonance (NMR) imaging radio frequency electromagnetic radiation is detected by the imaging sensors. Discuss the origin of this radiation.
Markscheme
«strong» magnetic field aligns proton «spins»
an RF signal is applied to excite protons
OR
change spin up to spin down state
protons de-excite/return to lower energy state
OR
proton relaxation occurs
with emission of RF radiation «that is detected»
OWTTE
Treat any mention of the following as neutral as they are not strictly relevant to the question:
gradient field, Larmor frequency, precession, resonance, 3-D image
[3 marks]
Examiners report
[N/A]
Syllabus sections
Option C: Imaging » Option C: Imaging (Additional higher level option topics) » C.4 – Medical imaging (HL only)
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