Distributed phase RF coil

Claim 2

A distributed phase RF coil arrangement for at least one of exciting a sample under NMR analysis with an oscillating magnetic field such as an RF field and for detecting nuclear magnetic resonance of the sample, and adapted for a relatively high degree of.magnetic coupling with the sample, said arrangement comprising: at least one electrically conductive loop defining an NMR sample reg-ion therewithin, said loop having alternating shielded and unshielded segments of predetermined lengths, said shielded segments defining inactive portions of said conductive loop and connecting pairs of unshielded segments, said unshielded segments defining active portions of the conductive loop for magnetically coupling with the sample, said unshielded segments adapted for current propagation along each of said active portions such that the propagation delay between points on said active portions is generally proportional to the angular displacement between said points of said active portions.

Claim 3

A distributed phase RF coil arrangement according to claim 1 further comprising: a) insulating means for supporting said electrically conductive loop; b) electrically conductive means for shielding a portion of the NMR sample region from RF irradiation, said shielded portion of the NMR sample region defining therewithin a first inactive portion and thereby delimiting the non-shielded active portion of the sample region; and c) means electrically connected to said shielding means for electrostatically decoupling a sample within the active portion of the NMR sample region.

Claim 4

A distributed phase RF coil arrangement according to claim 2 wherein said decoupling means decouples the NMR sample from electric fields of said conductive loop and said conductive loop from electrostatic atmospheric noise.

Claim 5

A distributed phase RF coil arrangement accord-ing to any of claims 1 through 3 wherein said shielded segments connect adjacent pairs of unshielded segments.

Claim 6

A distributed phase RF coil arrangement according to any of claims 1 through 3 wherein said shielded segments connect diametrically opposed pairs of unshielded segments.

Claim 7

A distributed phase RF coil arrangement for at least one of exciting a sample under NMR analysis with an oscillating magnetic field such as an RF field and for detecting nuclear magnetic resonance of said sample, and adapted for a relatively high level of magnetic coupling with said sample, which comprises: a) a coil support defining an NMR sample region therewithin; b) electrically conductive means for shielding a portion of the-NMR sample region from RF irradiation, said shielded portion of the NMR sample region defining therewithin a first inactive portion and thereby delimiting the non-shielded active portion of the sample region; c) means electrically connected to said shielding means for decoupling a sample within the active portion of the NMR sample region from electric fields of the coil generated by an RF magnetic field and for shielding said sample from axial components of said RF magnetic field and from electrostatic atmospheric noise; and d) an electrically conductive loop peripherally disposed about said coil support having alternating shielded and unshielded segments for magnetically coupling normal components of said RF field with said sample wherein: i) said shielded segments define inactive regions of said conductive loop and connect pairs of unshielded segments; and ii) said unshielded segments define active regions of said conductive loop, said unshielded segments being disposed about the active portion of the NMR sample region in generally axial relation with said coil former adapted for current propagation along each of said active region segments such that the phase delay between adjacent pairs of active segments of said coil is generally proportional to the angular displacement between said pair of active segments, thereby generating a magnetic field having a relatively substantial normal component throughout the active portion of said NMR sample region.

Claim 8

A distributed phase RF coil arrangement for at least one of exciting a sample under NMR analysis with an oscillating magnetic field such as an RF field and for detecting nuclear magnetic resonance of said sample, and adapted for a relatively high level of magnetic coupling with said sample, which comprises: a) a coil support defining an NMR sample region therewithin; b) electrically conductive means for shielding a portion of the-NMR sample region from RF irradiation, said shielded portion of the NMR sample region defining therewithin a first inactive portion and thereby delimiting the non-shielded active portion of the sample region; c) means electrically connected to said shielding means for decoupling a sample within the active portion of the NMR sample region from electric fields of the coil generated by an RF magnetic field and for shielding said sample from axial components of said RF magnetic field and from electrostatic atmospheric noise; and d) an electrically conductive loop peripherally disposed about said coil support having alternating shielded and unshielded segments for magnetically coupling normal components of said RF field with said sample wherein: i) said shielded segments define inactive regions of said conductive loop and connect pairs of unshielded segments; and ii) said unshielded segments define active regions of said conductive loop, said unshielded segments being disposed about the active portion of the NMR sample region in generally axial relation with said coil former adapted for current propagation along each of said active region segments such that the phase delay between adjacent pairs of active segments of said coil is generally proportional to the angular displacement between said pair of active segments, thereby generating a magnetic field having a relatively substantial normal component throughout the active portion of said NMR sample region.

Claim 9

A distributed phase RF coil arrangement according to claim 6 wherein said coil support is a cylindrically shaped insulator.

Claim 10

A distributed phase RF coil arrangement according to claim 6 or 7 wherein said decoupling means comprises a plurality of wires wound about said coil support about the active portion of the NMR sample region.

Claim 11

A distributed phase RF coil arrangement according to claim 6, 7 or 8 which further comprises a second electrically conductive loop peripherally disposed about said coil support having alternating shielded and unshielded segments for magnetically coupling normal components of said RF field with said sample.

Claim 12

A distributed phase RF coil arrangement according to any of claims 6 to 9 wherein the normal component of said magnetic field is generally uniform through said NMR sample region.