Probe head for nuclear magnetic resonance measurements

1. A probe head for nuclear magnetic resonance measurements in an area of a measuring object surface, comprising a contact surface to be applied against said object surface, first means for generating a static magnetic field extending at least partially parallel to said object surface, a planar coil for generating a radio frequency magnetic field having components extending perpendicular to said object surface, and second means for concentrating a radio frequency magnetic field effective within said measuring object, said second means being configured as an aperture and being located between said planar coil and said contact surface.

2. The probe head of claim 1 , wherein said aperture comprises a first opening, and a slot extending away from said first opening.

3. The probe head of claim 1 , wherein said planar coil is configured as a loop-shaped conductive coating on a first substrate.

4. The probe head of claim 3 , wherein said loop-shaped conductive coating is provided with a second opening being essentially square-shaped.

5. The probe head of claim 1 , wherein said aperture is configured as a planar conductive coating on a second substrate, said coating being provided with a first opening.

6. The probe head of claim 5 , wherein said first opening is essentially square-shaped.

7. The probe head of claim 5 , wherein said planar coil is configured as a loop-shaped conductive coating provided with a second opening, wherein, further, said first and said second openings are arranged coaxially.

8. The probe head of claim 5 , wherein said planar coil is configured as a loop-shaped conductive coating provided with a second opening, wherein, further, said first and said second opening have an area ratio in the range of between 1:2 and 1:6.

9. The probe head of claim 8 , wherein said area ratio is about 1:4.

10. The probe head of claim 8 , wherein when said radio frequency magnetic field has a frequency of about 15 MHz, said first opening has dimensions of 2×2 mm and said second opening has dimensions of 4×4 mm.

11. The probe head of claim 5 , wherein said planar coil is configured as a loop-shaped conductive coating on a first substrate, said first substrate and said second substrate being configured as one same substrate, said planar coil and said aperture being located on opposite surfaces thereof.

12. The probe head of claim 1 , wherein said first means are configured as a U-shaped magnet system, said second and said third means being located between legs of said U.

13. The probe head of claim 12 , wherein said magnet system comprises two legs configured as permanent magnets interconnected by a yoke.

14. The probe head of claim 1 , wherein said planar coil is located within an electrically conductive housing having a side facing said object surface, said second means being arranged within said side.

15. The probe head of claim 14 , wherein means for matching and tuning said planar coil with respect to said radio frequency are provided within said housing.

16. The probe head of claim 14 , wherein a plurality of exchangeable housings is provided, each housing having each said second planar coil and said third means.