Automatic gradient shimming

The introduction of gradient shimming (that makes this procedure very easy to automate) together with the possibility of performing automatic tuning and matching (via the use of motors mounted on the probe body) has further improved the whole procedure. 

Figure 3.50. Automatic deuterium gradient shimming. Spectrum (a) was acquired with all z-axis shims set to zero. After less than two minutes of gradient shimming of the z-z shims (3 iterations) spectrum (b) was obtained. The solvent was DMSO and one scan was acquired for each deuterium gradient echo collected via the probe lock coil. Automatic switching for deuterium observation was achieved with a home-built switching device.

The availability of pulsed-field gradients makes it possible to automatically shim using NMR imaging techniques. In MRI we rely on the dominance of water in the human body to obtain... 

The drawback to this manual shimming process is that it is time consuming, and it does not lend itself well to the determination of spectra in an automated environment. With the advent of pulsed field gradients, this shimming process becomes much faster, and it can be applied to the determination of spectra automatically. 

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