Abstract
We consider typical cross-polarization pulse sequences such as those shown in Fig. 38.1. The first objective of this chapter is to treat the evolution of the density operator in the course of such pulse schemes in far-reaching generality. In a second step, we will give the solutions for special cases such as ordinary Hartmann/Hahn cross-polarization, the adiabatic variant, and slice-selective cross-polarization.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Notes
Note that in the high-field limit the coupling between heteronuclei is always “weak.” In the homonuclear case, the situation is less clear. In context with J cross-polarization one rather uses the complete coupling Hamiltonian \( {{H}_{J}} = hJ(Ix{{S}_{x}} + {{I}_{y}}{{S}_{y}} + {{I}_{z}}{{S}_{z}}) \) The coherence evolution subject to this “isotropic” Hamiltonian during the cross-polarization RF pulses is referred to as “isotropic mixing” [60, 86, 278].
Actually, this situation can be set up in the rigorous sense by selectively saturating the S spins with the aid of an RF pulse comb prior to the cross-polarization pulses.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 1997 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Kimmich, R. (1997). Single-Transition Operator Theory of Cross-Polarization. In: NMR. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-60582-6_39
Download citation
DOI: https://doi.org/10.1007/978-3-642-60582-6_39
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-64465-8
Online ISBN: 978-3-642-60582-6
eBook Packages: Springer Book Archive