Nuclear-magnetic-resonance line-shape theory in the presence of radiation damping.

Abstract

The Bloch equations with radiation damping terms are solved. Analytical results are obtained for the case where the longitudinal relaxation effect can be neglected. General line-shape expressions, which can be reduced to those in conventional NMR, are presented. The line-shape distortions of the NMR signals due to radiation damping effects are analyzed. Unusual intensity profiles as a function of the pulse-flip angle ${\mathrm{\ensuremath{\theta}}}_{0}$, which are strongly dependent on the ratio of ${\mathit{T}}_{2}^{\mathrm{*}}$/${\mathit{T}}_{\mathit{r}}$ (where ${\mathit{T}}_{2}^{\mathrm{*}}$ and ${\mathit{T}}_{\mathit{r}}$ are the effective transverse relaxation time and the radiation damping time, respectively), are predicted. Radiation damping effects on the phase and the linewidth of the signals are also discussed. Some experimental results are given.