title: Time symmetry: an application to shaped pulse excitation of spin-1 systems.
abstract: The role of time symmetry in the design of amplitude-modulated (shaped) pulses for spin-1 excitation is examined. The quaternion calculus is used to calculate the quaternion elements (Euler-Rodrigues parameters) of each shaped pulse. In this manner, it is shown how the simplicity and compactness of the Euler-Rodrigues parametrization can be used to significantly expedite a computer search for optimal time-symmetric shaped pulses. Theoretical and experimental tests of a new class of symmetric quadrupole-shaped (SQUASH) pulses identified by this procedure show a significant improvement in both excitation bandwidth and efficiency in comparison to the time-asymmetric QUASH shaped pulse previously identified.
authors.affiliation: Department of Physics, The University of Lethbridge, AB, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Habot
authors.forename: D
authors.initials: D
authors.lastname: Lu
authors.forename: N J
authors.initials: NJ
authors.lastname: Tagg
authors.forename: G R
authors.initials: GR
authors.lastname: Gall
authors.forename: D J
authors.initials: DJ
authors.lastname: Siminovitch
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008432:Mathematical Computing