Multi-frequency improved constant amplitude pulses for broadband inversion.
Optimization of constant amplitude broadband inversion pulses for maximum inversion over a range of multiple fields yields more regular pulses with better tolerance to B(1) errors than those optimized for a single field. These multi-frequency improved constant amplitude (MICA) pulses as constructed for (13)C broadband inversion give best results for HMQC and especially HSQC type experiments. Most of the advantages of MICA pulses versus other inversion pulses in these experiments can be attributed to their relatively short durations. Linearly truncated versions of these pulses do not offer any advantage over MICA pulses for these applications. MICA inversion pulses can also be used for decoupling and a (13)C decoupling example gives twice the decoupling bandwidth as the GARP1 sequence at the same power level with no appreciable increase in decoupling sidebands.
Brown
Douglas
D
Department of Chemistry, Indiana University, Bloomington, IN 47405, USA. doebrown@indiana.edu