Pulsed Nuclear Magnetic Resonance

at Hobart and William Smith Colleges dept. of Physics

Fall 2019

This experiment is a much more bare-bones, fundamental version of the nuclear magnetic resonance spectra taken in my organic chemistry work. This technique uses non-invasive magnetic pulses in order to investigate properties unique to different samples containing spin 1/2 nuclei (1H, 13C, etc). This same technique is also the basis behind medical magnetic resonance imaging.

Here, a pulsed radio frequency magnetic field and a static magnetic field was applied to two different samples in pulses of tuned lengths and of resonant frequency with the sample.

By varying the time between two pulses of tuned length, the resulting magnetization of the sample was then measured. From differently timed pulses, the characteristic properties of spin-spin relaxation time and spin-lattice relaxation time can be found.

Echo.PNG

A plot showing the net magnetization in the xy plane (CH1, yellow) and the applied radio-frequency pulses (CH4, green). Time between these pulses are varied in order to measure the spin-lattice relaxation time.

Pulsed NMR Paper