title: Detection of acoustic waves by NMR using a radiofrequency field gradient.
abstract: A B(1) field gradient-based method previously described for the detection of mechanical vibrations has been applied to detect oscillatory motions in condensed matter originated from acoustic waves. A ladder-shaped coil generating a quasi-constant RF-field gradient was associated with a motion-encoding NMR sequence consisting in a repetitive binomial 13;31; RF pulse train (stroboscopic acquisition). The NMR response of a gel phantom subject to acoustic wave excitation in the 20-200 Hz range was investigated. Results showed a linear relationship between the NMR signal and the wave amplitude and a spectroscopic selectivity of the NMR sequence with respect to the input acoustic frequency. Spin displacements as short as a few tens of nanometers were able to be detected with this method.
authors.affiliation: Magnetic Resonance Center, University of Rennes 1 and Centre Eugène Marquis, Rennes, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Madelin
authors.forename: Nathalie
authors.initials: N
authors.lastname: Baril
authors.forename: Czeslaw J
authors.initials: CJ
authors.lastname: Lewa
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Franconi
authors.forename: Paul
authors.initials: P
authors.lastname: Canioni
authors.forename: Eric
authors.initials: E
authors.lastname: Thiaudiére
authors.forename: Jacques D
authors.initials: JD
authors.lastname: de Certaines
mesh_terms: D000162:Acoustics; D004574:Electromagnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008954:Models, Biological; D019047:Phantoms, Imaging; D014465:Ultrasonics; D014732:Vibration