We have focused on the development of frequency-swept pulses, known as adiabatic pulses, which compensate for imperfect radiofrequency field (B1) uniformity and resonance offsets. The wide tolerance to B1 inhomogeneity with adiabatic pulses is particularly advantageous in experiments which use a surface transceiver coil to enhance sensitivity. When using a volume coil with uniform B1, adiabatic pulses can still perform better than conventional pulses in many cases. Results in general show that adiabatic pulses are advantageous for many different areas of NMR research ranging from in vivo spectroscopy and imaging to macromolecular structure determination with high resolution NMR spectroscopy. In the past year, we developed new pulses and methods for broadband heteronuclear decoupling with adiabatic pulses were introduced leading to sensitivity enhancement while simultaneously reducing artifacts and permitting automation of complex pulse sequences. A general concatenation procedure to create adiabatic refocusing pulses with bandwidths proportional to the average rather than peak power was developed; these pulses also have symmetric frequency (or slice) profiles and offers unlimited possibilities for concatenating AFP pulses together using any odd number of constituent AFP.
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