Multiple tuned scroll coil

• US 20060017438A1
• Filed: 07/26/2004
• Published: 01/26/2006
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Varian Incorporated (Agilent Technologies, Inc.)
• Inventors: Mehr, Knut G., Mullen, Charles G., Stringer, John A.
• Granted Patent: US 7,081,753 B2
• Time in Patent Office: Days
• US Class Current: 324/318
• CPC Class Codes: G01R 33/34092 RF coils specially adapted for NMR spectrometers
• CPC Class Codes: G01R 33/3635 Multi-frequency operation

Abstract

A sample probe and apparatus are provided for magnetic resonance experiments. The probe includes a coil simultaneously tunable to at least two different frequencies. The coil includes a section having a scroll configuration and defines a core into which a sample can be inserted. A multi-resonant circuit transmits RF energy to the coil at two or more different frequencies for exciting nuclei of the sample. The apparatus includes a coil having a scroll configuration. RF transmission circuitry transmits RF energy to the coil at two or more different frequencies. RF receiving circuitry receives an RF signal responsive to excitation. A coil is magnetically coupled with a sample at an RF frequency.

Claims

1. A sample probe for magnetic resonance experiments, comprising:

(a) a coil simultaneously tunable to at least two different frequencies and comprising a section having a scroll configuration and defining a core into which a sample can be inserted; and

(b) a multi-resonant circuit communicating with the coil for transmitting RF energy to the coil at two or more different frequencies for exciting nuclei of the sample.

2. The probe according to claim 1, comprising a device for spinning the sample about an axis of the sample.

3. The probe according to claim 1, comprising a structure for holding the sample in an orientation in which the sample axis is at an angle to the direction of an applied static magnetic field.

4. The probe according to claim 3, comprising a device for spinning the sample about the sample axis while the sample is held at the angle.

5. The probe according to claim 3, wherein the angle is a magic angle.

6. The probe according to claim 1, wherein the multi-resonant circuit is adapted for transmitting a sequence of one or more signals operative to induce cross polarization between at least two nuclei of the sample.

7. The probe according to claim 1, wherein the two or more different frequencies comprise at least one frequency for exciting a proton.

8. The probe according to claim 7, wherein the two or more different frequencies comprise at least one frequency for exciting a ¹³C nucleus.

9. The probe according to claim 8, wherein the two or more different frequencies comprise at least a third frequency for exciting a nucleus having a gyromagnetic ratio between the gyromagnetic ratio of a proton and the gyromagnetic ratio of a ¹³C nucleus.

10. The probe according to claim 7, wherein the two or more different frequencies comprise at least one frequency for exciting a nucleus having a gyromagnetic ratio between the gyromagnetic ratio of a proton and the gyromagnetic ratio of a ¹³C nucleus.

11. The probe according to claim 1, wherein the section of the coil having the scroll configuration comprises a layer of material axially extending from a first end region, through a central region, and to a second end region, and the layer has a greater thickness in the end regions than in the central region.

12. A magnetic resonance apparatus comprising:

(a) a coil simultaneously tunable to at least two different frequencies and including a section having a scroll configuration and defining a core into which a sample can be inserted;

(b) RF transmission circuitry communicating with the coil for transmitting RF energy to the coil at two or more different frequencies for exciting nuclei of the sample; and

(c) RF receiving circuitry communicating with the coil for receiving an RF signal responsive to excitation.

13. The apparatus according to claim 12, comprising a sample probe for containing the sample, wherein the coil is housed in the sample probe.

14. The apparatus according to claim 13, wherein the sample probe comprises a multi-resonant circuit tunable to the two or more different frequencies and communicating with the RF transmission circuitry.

15. The apparatus according to claim 12, comprising circuitry for producing a frequency-domain spectrum based on the received RF signal.

16. A coil for magnetically coupling with a sample at an RF frequency, comprising:

section having a scroll configuration and defining a core into which the sample can be inserted, the section including a layer of electrically conductive material axially extending from a first end region, through a central region, and to a second end region, the layer having a greater thickness in the end regions than in the central region.

17. The coil according to claim 16, wherein the layer is folded in the end regions to give the greater thickness.

18. The coil according to claim 16, wherein the layer is wrapped around the core a plurality of times to define a plurality of wraps circumferentially extending around the core, and the layer has the greater thickness in the end regions along each wrap.

19. The coil according to claim 16, wherein the coil forms a multi-resonance circuit with an input of RF energy for exciting nuclei of the sample requiring different resonance conditions for absorption of the RF energy.