title: Broadband excitation pulses with variable RF amplitude-dependent flip angle (RADFA).
abstract: Pulse sequences in NMR spectroscopy sometimes require the adjustment of effective flip angles with respect to experiment-specific or sample-specific parameters. Here, we present a quality factor for efficient optimization of offset-compensated broadband excitation pulses with RF amplitude-dependent effective flip angles (RADFA). After proof of principle, physical limits of RF amplitude-restricted and RF power-restricted broadband RADFA pulses are explored and corresponding pulse shapes and performances characterized in detail.
authors.affiliation: Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021 Karlsruhe, Germany.
authors.forename: Martin R M
authors.initials: MR
authors.lastname: Koos
authors.affiliation: Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
authors.forename: Hannes
authors.initials: H
authors.lastname: Feyrer
authors.affiliation: Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021 Karlsruhe, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Luy
mesh_terms: D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
keywords: Ernst angle; broadband pulse; excitation pulse; optimal control theory; variable flip angle