Single-sided NMR sensor with microscopic depth resolution
AssigneeAixNMR Zentrum für Magnetische Resonanz e.V.
InventorsBernhard Blumich, Federico Casanova, Juan Perlo
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Abstract
A low-cost single-sided NMR sensor to produce depth profiles with microscopic spatial resolution is presented. The open geometry of the NMR sensor provides a non-invasive and non-destructive testing method to characterize the depth structure of objects of arbitrary size. The permanent magnet geometry generates one plane of constant magnetic field intensity parallel to the scanner surface. By combining the highly uniform static gradient with selective RF excitation, a thin flat sensitive slice can be defined. By moving the relative position between the slice and the object, one-dimensional profiles of the near surface of large samples are produced with high spatial resolution.
Claims16
An open single-sided magnetic resonance sensor for scanning sample depth profiles with microscopic resolution comprising:
- (a) at least four permanent magnet blocks separated by two perpendicular gaps for generation of a static magnetic field having a spatially dependent intensity;
- (b) a radio-frequency coil for exciting and detecting an NMR signal positioned at a determined position above the magnet blocks defining a maximum depth into a sample;
- and
- (c) a tuning circuit for the radio-frequency coil including an input/output connection.
An apparatus comprising:
- (a) an open single-sided magnet resonance sensor for scanning sample depth profiles with microscopic resolution comprising at least four permanent magnetic blocks separated by two perpendicular gaps for generation of a static field having a spatially dependent intensity, a radio-frequency coil for exciting and detecting an NMR signal positioned at a determined position above the magnet blocks defining a maximum depth into a sample, and a tuning circuit for the radio-frequency coil including an input/output connection;
- and
- (b) a mechanical device for moving the sample or the sensor to vary a position of a sensitive slice inside the sample.
A method of single-sided nuclear magnetic resonance imaging comprising the steps of:
- (a) generating a magnetic field with a uniform magnetic field gradient using an open single-sided magnetic resonance sensor comprising at least four permanent magnet blocks separated by two perpendicular gaps for generating a static field having a spatially dependent intensity, a radio-frequency coil for exciting and detecting a NMR signal positioned at a determined position above the magnet blocks defining a maximum depth into the sample, and a tuning circuit for the radio-frequency coil including an input/output connection;
- (b) positioning an area of the uniform magnetic field gradient at a volume of interest in the sample;
- (c) producing at least one magnetic field component approximately transverse to the magnetic field, said at least one magnetic field component being selected from the group consisting of an oscillating magnetic field and a rotating magnetic field;
- and
- (d) measuring an electromagnetic response from the volume of interest.
Dependencies are inferred from the claim text.