Nuclear spin noise in NMR revisited
Abstract
The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparison to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the Spin-Noise and Frequency-Shift Tuning Optima.
Keywords
Cite
@article{arxiv.1507.01398,
title = {Nuclear spin noise in NMR revisited},
author = {Guillaume Ferrand and Gaspard Huber and Michel Luong and Hervé Desvaux},
journal= {arXiv preprint arXiv:1507.01398},
year = {2015}
}