NMR probe
An NMR probe is offered which enables a 1 H/ 19 F compatibility mode having a sample coil, a hollow tubular body, and two rod electrodes disposed inside the tubular body substantially in a parallel relationship to each other. The tubular body is formed by a conductive wall at ground potential. An RF input-output portion corresponding to the resonant frequency of 1 H nucleus is connected with the one end of the coil via a tuning and matching device. Another RF input-output port corresponding to the resonant frequency of 19 F nucleus is connected with an end of the coil via another tuning and matching device.
1. An NMR probe comprising:
a sample coil having two ends A and B;
a hollow tubular body formed by a conductive wall at ground potential, the tubular body having one wall surface having an open portion; and
two rod electrodes disposed inside the hollow tubular body substantially in a parallel relationship to each other axially of the tubular body,
wherein respective one ends of the two rod electrodes are connected with the ends A and B, respectively, of the sample coil through the open portion, while other ends of the rod electrodes are electrically grounded to the hollow tubular body at a wall surface located opposite to the wall surface having the open portion,
wherein an RF input-output port corresponding to a resonant frequency of 1 H nucleus is connected with the end A of the sample coil via a tuning and matching device, and
wherein another RF input-output port corresponding to a resonant frequency of 19 F nucleus is connected with the end B of the sample coil via another tuning and matching device.
2. An NMR probe as set forth in claim 1 , wherein said rod electrodes are substantially (2n−1) times as long as a quarter wavelength of resonating RF radiation, where n is a natural number.
3. An NMR probe comprising:
a sample coil having two ends A and B;
a hollow tubular body formed by a conductive wall at ground potential, the tubular body having two opposite wall surfaces each having an open portion; and
two rod electrodes disposed inside the hollow tubular body substantially in a parallel relationship to each other axially of the tubular body,
wherein respective one ends of the two rod electrodes are connected with the ends A and B, respectively, of the sample coil via one of the open portions, while other ends of the electrodes are made open at the other open portion,
wherein an RF input-output port corresponding to a resonant frequency of 1 H nucleus is connected with the end A of the sample coil via a tuning and matching device, and
wherein another RF input-output port corresponding to a resonant frequency of 19 F nucleus is connected with the end B of the sample coil via another tuning and matching device.
4. An NMR probe as set forth in claim 1 , wherein said rod electrodes are substantially 2n times as long as a quarter wavelength of resonating RF radiation, where n is a natural number.
5. An NMR probe as set forth in claim 1 or 3 , wherein the rod electrode connected with the end A is thicker than the rod electrode connected with the end B.
6. An NMR probe as set forth in claim 1 or 3 , wherein the two rod electrodes connected with the two ends A and B, respectively, of the sample coil are designed to be capable of freely establishing and breaking connection between the ends A and B.
7. An NMR probe as set forth in claim 1 or 3 , wherein said sample coil has a capacitive component, and wherein the ratio of detection sensitivity on an RF side corresponding to the resonant frequency of 1 H nucleus to detection sensitivity of an RF side corresponding to the resonant frequency of 19 F nucleus can be varied by controlling magnitude of the capacitive component.
8. An NMR probe as set forth in claim 1 or 3 , wherein additional sample coils are arranged concentrically around the first-mentioned sample coil, and wherein the additional sample coils can resonate with an LF frequency or with a lock frequency.
9. An NMR probe as set forth in claim 1 or 3 , wherein said hollow tubular body has a polygonal cross section having an inside dimension substantially equal to or less than an inside diameter of an assembly consisting of a superconducting NMR magnet and room temperature shims mounted in bores formed in the magnet.
10. An NMR probe as set forth in claim 1 or 3 , wherein said hollow tubular body has a circular cross section having an inside dimension substantially equal to or less than an inside diameter of an assembly consisting of a superconducting NMR magnet and room temperature shims mounted in bores formed in the magnet.
11. An NMR probe as set forth in claim 1 or 3 , wherein said hollow tubular body has an elliptical cross section having an inside dimension substantially equal to or less than an inside diameter of an assembly consisting of a superconducting NMR magnet and room temperature shims mounted in bores formed in the magnet.