The Physics of NMR

  • Quantum mechanics
  • Which nuclei?
  • Spin
  • Magnetise patients..
  • ..then excite them!
  • Building blocks
  • Getting a signal
  • Time to relax...
  1. NMR occurs because certain atomic nuclei have a property known as spin

  2. ‘Spin’ (I) is a quantum-mechanical property of the nucleus

  3. Nuclei with even numbers of protons and neutrons have no spin

  4. Nuclei with an odd number of protons and/or an odd number of neutrons have integer spin (I = 1, 2, 3…) or half-integer spin (I = 1/2, 3/2, 5/2…)

  5. Only these nuclei with nonzero spin can be studied using NMR

There is no exact classical analogy for quantum-mechanical spin. A model that works well for many purposes is to picture the nucleus as a solid ball, and a nucleus with spin as rotating on an axis through its centre at a speed that is dependent on the quantum number.