Pulsed Nuclear Magnetic Resonance (Pulsed NMR)
In this experiment students are introduced to the modern NMR techniques underlying such applications as magnetic resonance imaging and mapping the structure of complicated organic molecules. Students learn how to put the sample in specific spin states, and then how to manipulate these spin states to accurately measure the longitudinal (spin-lattice) and transverse (spin-spin) relaxation times. In the process of mastering this "spin engineering", students learn how pulsed NMR techniques provide quantitative information about the spins and their environment that is not accessible using the simpler continuous wave NMR technique.
Experiment Information
- Write-up.
- The TeachSpin PSA-1 manual: There are 5 sections, but you will
probably only want to look at the first 3.
- Introduction (gives theoretical background), pp. 1-13.
- The Instrument (describes details of the instrumentation), pp. 14-24.
- Getting Started (introductory exercises), pp. 25-34.
- Experiments (more advanced investigations), pp. 35-36.
- Specifications (instrument specifications)
Background Information
- Lecture notes on NMR
- Hahn, E. L., "Free nuclear induction", Physics Today, Nov. 1953, pp. 4-9.
- Hahn, E. L., "Spin echoes", Phys. Rev., 80, 580-594 (1950).
- Carr, H. Y., and E. M. Purcell, "Effects of diffusion on free precession in nuclear magnetic resonance experiments", Phys. Rev., 94, 630-638 (1954).
- Meiboom, S., and D. Gill, "Modified spin-echo method for measuring nuclear relaxation times", Rev. Sci. Inst., 29, 688-691 (1958).
- Simpson, J. H., and H. Y. Carr, "Diffusion and nuclear spin relaxation in water", Phys. Rev., 111, 1201-1202 (1958).
- "Explosives Detection with Nuclear Quadrupole Resonance", by J. B. Miller and G. A Barrall, American Scientist, vol. 93, pp. 50-57 (Jan-Feb 2005). Recent article which discusses how nuclear quadrupole resonance (NQR) is being used in new technology to detect explosives. The quadrupole moment is an important aspect of the ammonia inversion experiment, and the physics of NQR is similar to NMR.
Other information is found on the page for Continuous NMR.