BIOLOGY 1A03 Lecture Notes - Lecture 16: Bulk Modulus, Larmor Precession, Gyromagnetic Ratio

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Alastair Tracey

Document Summary

Protons are spinning charged particles, they have a magnetic dipole as a result. Body mostly made up of water that has hydrogens atoms which consist of a proton. Magnetic moments of protons are all random initially have a resultant vector of zero as they are oriented in random directions. Apply an external magnetic field to the protons and they will attempt to align with the magnetic field. Majority go into a low energy parallel state while the others go to a high energy anti-parallel state. However the spins cannot perfectly align themselves with the direction of the external magnetic field and they will experience a torque force and precess at the larmor frequency (based off external magnetic field times gyromagnetic ratio) Combination of parallel and antiparallel spins results in a net magnetic moment in the positive z direction (called the bulk modulus vector)