title: Broadband excitation pulses for high-field solid-state nuclear magnetic resonance spectroscopy.
abstract: In nuclear magnetic resonance spectroscopy, experimental limits due to the radiofrequency transmitter and/or coil means that conventional radiofrequency pulses ("hard pulses") are sometimes not sufficiently powerful to excite magnetization uniformly over a desired range of frequencies. Effects due to nonuniform excitation are most frequently encountered at high magnetic fields for nuclei with a large range of chemical shifts. Using optimal control theory, we have designed broadband excitation pulses that are suitable for solid-state samples under magic-angle-spinning conditions. These pulses are easy to implement, robust to spinning frequency variations, and radiofrequency inhomogeneities, and only four times as long as a corresponding hard pulse. The utility of these pulses for uniformly exciting (13) C nuclei is demonstrated on a 900 MHz (21.1 T) spectrometer.
authors.affiliation: Department of Chemistry, Lewis & Clark College, 0615 SW Palatine Hill Road, Portland, OR, 97219, USA. loening@lclark.edu
authors.forename: Nikolaus M
authors.initials: NM
authors.lastname: Loening
authors.forename: Barth-Jan
authors.initials: BJ
authors.lastname: van Rossum
authors.forename: Hartmut
authors.initials: H
authors.lastname: Oschkinat
mesh_terms: D002247:Carbon Isotopes; D003198:Computer Simulation; D060526:Magnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011846:Radio Waves
chemical_list: D002247:Carbon Isotopes