SORDOR Pulses: Expansion of the Böhlen-Bodenhausen Scheme for Low-Power Broadband Magnetic Resonance

Abstract

Abstract. A novel type of efficient broadband pulses, called SORDOR (second order phase dispersion by optimized rotation pulses), has recently been introduced. In contrast to adiabatic excitation, SORDOR-90 pulses provide effective transverse 90° rotations throughout their bandwidth, with a quadratic offset dependence of the phase in the x,y-plane. Together with phase-matched SORDOR-180 pulses, this enables the Böhlen-Bodenhausen broadband spectroscopy approach for frequency-swept pulses to be extended to any type of 90°/180° pulse-delay sequence. Example pulse shapes are characterised in theory and experiment and an example broadband application is given with a 19F-PROJECT experiment for measuring T2-relaxation times without distortions due to J-coupling evolution.

Band-selective universal 90° and 180° rotation pulses covering the aliphatic carbon chemical shift range for triple resonance experiments on 1.2 GHz spectrometers

“…A large variety of pulses has been optimized using GRAPE-derived algorithms (Skinner et al 2003(Skinner et al , 2004Kobzar et al 2004;Skinner et al 2005Skinner et al , 2006Gershenzon et al 2007Gershenzon et al , 2008Kobzar et al 2008;Skinner et al 2012a, b;Ehni and Luy 2012;Nimbalkar et al 2013;Ehni and Luy 2013;Goodwin et al 2020;Ehni et al 2022;Haller et al 2022), including UR pulses (Skinner et al 2012a;Kobzar et al 2012). However, the cost function originally introduced in the GRAPE publication (Khaneja et al 2005…”