Chapter 13 Scattering wavevector analysis of pulsed gradient spin echo data

Abstract

The scattering analogy provides a useful description of the Pulsed Gradient Spin Echo (PGSE) method. It lends itself naturally to the use of Fourier analysis and the mathematics of diffraction when designing PGSE experiments and in treating the resulting echo signals. Care is needed in allowing for finite time, finite pulse width and relaxation effects. This chapter examines the use of conventional least squares approaches to multi-parameter fitting that can result in valuable structural and dynamical insight. When used as a contrast in imaging, the PGSE method allows the motion to be spatially localized. The use of Fourier analysis provides access to the local propagator and permits the use of fitting procedures, which reveal motional features of specific interest. The use of sophisticated localized propagator analysis offers promising avenues of investigation in the development of more powerful nuclear magnetic resonance (NMR) imaging methodologies.