Physics 111 Advanced Laboratory. Larry Wald This video part 2 accompanies the Nuclear Magnetic Resonance Experiment, providing students with an introduction to the theory, apparatus, and procedures. In the NMR experiment, nuclear dipoles (the samples) are subjected to a static magnetic field of about 4000 gauss as well as a time-varying radio-frequency magnetic field perpendicular to the static field. The static field causes Zeeman-effect splitting between sub-states, and the radio frequency field is tuned to the Larmor frequency so that it induces transitions between the sub-states. The resonance condition is observed using the Bloch two-coil induction technique. You will observe proton and fluorine nuclei. You will learn techniques of lock-in detection and signal averaging. A second part of this experiment uses a pulsed radiofrequency field rather than a continuous-wave (CW) field. Signals are detected immediately after the pulsed excitation stops. The observable effects are comparable to the free vibration or ringing of a resonant cavity on an atomic scale. This is the basis of Magnetic Resonance Imaging (MRI) in the medical field today. http://advancedlab.org