AI Article Synopsis
- The study focuses on how relative phase manipulations in multipulse sequences can effectively counteract common errors in J-spectroscopy, particularly when using CPMG during data acquisition.
- Past discussions on supercycles have primarily centered on extending the decay of magnetization in time-domain NMR, but this research uses simple spin systems to directly compare simulated outcomes with experimental data.
- The findings highlight that off-resonance effects significantly impact spin dynamics within the specific multiplet being studied, with the optimal phase cycling for their method being a 4-pulse cycle achieving robust results in both thermally polarized and hyperpolarized scenarios.
Article Abstract
We demonstrate that the relative phases in the refocusing pulses of multipulse sequences can compensate for pulse errors and off-resonant effects, which are commonly encountered in J-spectroscopy when CPMG is used for acquisition. The use of supercycles has been considered many times in the past, but always from the view point of time-domain NMR, that is, in an effort to lengthen the decay of the magnetization. Here we use simple spin-coupled systems, in which the quantum evolution of the system can be simulated and contrasted to experimental results. In order to explore fine details, we resort to partial J-spectroscopy, that is, to the acquisition of J-spectra of a defined multiplet, which is acquired with a suitable digital filter. We unambiguously show that when finite radiofrequency pulses are considered, the off-resonance effects on nearby multiplets affects the dynamics of the spins within the spectral window under acquisition. Moreover, the most robust phase cycling scheme for our setup consists of a 4-pulse cycle, with phases yyyy‾ or xxxx‾ for an excitation pulse with phase x. We show simulated and experimental results in both thermally polarized and PHIP hyperpolarized systems.
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Article Synopsis
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- Past discussions on supercycles have primarily centered on extending the decay of magnetization in time-domain NMR, but this research uses simple spin systems to directly compare simulated outcomes with experimental data.
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