RF coil for magic angle spinning probe
AssigneeVarian, Inc.
InventorWai Ha Wong
Life of this patent
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Abstract
A multimode RF probe for use with a sample oriented at an angle θ to a polarizing field B0 produces a resultant RF magnetic field exhibiting enhanced coupling to the sample. The multiple modes are furnished by a quadrature coil, or a solenoidal coil in combination with either a saddle coil or quadrature coil.
Claims19
An NMR probe for use with a polarizing magnetic field B0, comprising:
- a resonator having a cylindrical axis R, said axis R inclined at an angle θ to B0, said resonator sustaining a plurality of RF magnetic fields each comprising a distinct phase and direction, and
- a sample retainer for holding an elongate sample along said cylindrical axis.
An NMR system comprising:
- a magnet for producing a polarizing field B0,
- an RF energy source,
- an RF receiver for detecting and resolving RF energy at selected frequency and phase, and
- an RF probe comprising a resonator having a cylindrical axis R, said axis R inclined at an angle θ to B0, said resonator sustaining a plurality of RF magnetic fields each comprising a distinct phase and direction.
A method of establishing an RF magnetic field within an NMR probe of cylindrical symmetry comprising a symmetry axis, said RF magnetic field to exhibit a desired orientation with respect to another axis B0 inclined with respect to said symmetry axis, comprising the steps of:
- (a) energizing a first RF magnetic field amplitude A1 oriented along said symmetry axis at resonant frequency ω0, and phase ρ1, and
- (b) in substantial concurrence with step (a), energizing a second RF magnetic field amplitude A2 in a plane normal to said symmetry axis at resonant frequency ω0 and phase ρ2.
A method of establishing a plane polarized RF magnetic field within an NMR probe of cylindrical symmetry comprising a symmetry axis, said symmetry axis to exhibit a desired orientation with respect to another axis B0 inclined with respect to said symmetry axis, comprising the steps of:
- (a) energizing a first RF magnetic field comprising vector amplitude A1 in a plane orthogonal to said symmetry axis, said first RF field comprising resonant frequency ω0, amplitude A1 and phase ρ1;
- and
- (b) in substantial concurrence with step (a), energizing a second RF magnetic field comprising vector amplitude A2 in said plane normal to said symmetry axis and orthogonal to said vector amplitude A1 said second RF magnetic field comprising resonant frequency ω0 and phase ρ1+π/2.
Dependencies are inferred from the claim text.