Introducing an NMR apparatus comprising cooled probe components via a vacuum lock

Patent metadata

Field	Value
Publication number	US-9958520-B2
Application number	US-201715673063-A
Country	US
Kind code	B2
Filing date	Aug 9, 2017
Priority date	Aug 9, 2016
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An NMR apparatus includes a superconducting magnet assembly, a cryostat having a vacuum vessel, a refrigeration stage that can be operated at a temperature of <100 K, and a magnet coil system that comprises a cold bore into which a room temperature access of the cryostat engages. The NMR apparatus also includes an NMR probe with probe components cooled to an operating temperature of <100 K. The probe components are arranged between the cold bore and the room temperature access into the cold bore, radially inside the cold bore but outside the room temperature access. The vacuum vessel includes an opening that can be closed by a lock valve. A lock chamber is directly connected to the opening, such that the cooled probe components can be installed and/or removed through the opening and lock valve without breaking the vacuum in the vacuum vessel of the cryostat.

First claim

What is claimed is:

1. A Nuclear Magnetic Resonance (NMR) apparatus comprising:
a superconducting magnet assembly comprising:
a cryostat with a vacuum vessel and a refrigeration stage at an operating temperature of <100 K, wherein the vacuum vessel includes an opening operable to be closed with a lock valve, and a lock chamber which is directly connected to the opening or a device for attaching the lock chamber to the opening such that the lock chamber and the opening are directly connected; and
a superconducting magnet coil system with a cold bore into which a room temperature access of the cryostat engages; and

an NMR probe including probe components cooled to an operating temperature of <100 K, wherein the cooled probe components are arranged, at least in part, in a region between the cold bore of the superconducting magnet coil system and the room temperature access of the cryostat into the cold bore, radially inside the cold bore and outside the room temperature access of the cryostat,
wherein the opening and the lock valve are sized and arranged such that the cooled probe components are installed and/or removed through the opening and the lock valve.

2. The NMR apparatus according to claim 1 , wherein the cooled probe components arranged in the region between the cold bore of the superconducting magnet coil system and the room temperature access of the cryostat into the cold bore include a high frequency (HF) coil.

3. The NMR apparatus according to claim 1 , further comprising a mechanically releasable thermal contact between the cooled probe components and the refrigeration stage of the cryostat.

4. The NMR apparatus according to claim 3 , wherein the refrigeration stage comprises a nitrogen vessel, and wherein the cooled probe components are coupled through the mechanically releasable thermal contact to the nitrogen vessel.

5. The NMR apparatus according to claim 3 , wherein the refrigeration stage comprises a radiation shield, which is cooled by a single-stage cryocooler, and wherein the cooled probe components are coupled through the mechanically releasable thermal contact to the radiation shield cooled by the single-stage cryocooler.

6. The NMR apparatus according to claim 3 , wherein the refrigeration stage comprises a radiation shield which is cooled by a first stage of a two-stage cryocooler, and wherein the cooled probe components are coupled through the mechanically releasable thermal contact to the radiation shield cooled by the first stage of the two-stage cryocooler.

7. The NMR apparatus according to claim 3 , wherein the superconducting magnet coil system is cooled by a single-stage cryocooler, and wherein the cooled probe components are coupled through the mechanically releasable thermal contact to the superconducting magnet coil system cooled by the single-stage cryocooler.

8. The NMR apparatus according to claim 3 , wherein the mechanically releasable thermal contact comprises a first thermal contact element formed as a cone and a second thermal contact element formed as an interlocking mating cone, the cone and the interlocking mating cone being produced from a heat-conductive material having a heat conductivity of greater than 20 W/(K*m) at the operating temperature, wherein the cone and the interlocking mating cone are coated with a noble metal, and wherein the cone and the interlocking mating cone are pressed against one another by a spring element with a force of at least 20 N.

9. The NMR apparatus according to claim 8 , wherein the heat-conductive material comprises copper, and wherein the noble metal comprises gold.

10. The NMR apparatus according to claim 1 , wherein the cooled probe components are cooled from outside the cryostat with an external cooling circuit.

11. The NMR apparatus according to claim 1 , wherein the cooled probe components include normally conducting or superconducting components.

12. The NMR apparatus according to claim 3 , wherein the mechanically releasable thermal contact comprises a probe-side thermal contact element and a refrigeration-stage-side thermal contact element, the probe-side thermal contact element being colder than the refrigeration-stage-side thermal contact element.

13. The NMR apparatus according to claim 1 , wherein the NMR probe is designed such that, in an installed state, a part of the NMR probe closes the lock valve in the opening of the vacuum vessel in an air-tight manner, enabling the lock chamber to be detached.

14. The NMR apparatus according to claim 1 , wherein the superconducting magnet coil system comprises low temperature superconducting (LTS) elements or high temperature superconducting (HTS) elements.

15. The NMR apparatus according to claim 1 , wherein the superconducting magnet assembly includes a shim system, and wherein the shim system includes an active shim system comprising shim coils, or a passive shim system comprising one or more ferromagnetic field-shaping elements, and wherein the shim system is arranged inside the cryostat in order to homogenize a magnetic field, and wherein the shim system is arranged between the cold bore of the superconducting magnet coil system and the cooled probe components, and wherein the shim system is thermally attached to the refrigeration stage of the cryostat or to an external cooling circuit.

16. A method for installing and removing probe components in/from the vacuum vessel of the cryostat of the superconducting magnet assembly of the NMR apparatus according to claim 13 , the method comprising:
decoupling connection lines of the NMR probe to other parts of the NMR apparatus;
attaching the lock chamber to the lock valve;
evacuating the lock chamber;
moving probe components to be removed out of the vacuum vessel of the cryostat and into the lock chamber;
closing the lock valve;
flooding and opening the lock chamber, and taking out the probe components to be removed;
introducing probe components to be installed into the lock chamber, and closing and evacuating the lock chamber;
opening the lock valve;
moving the probe components to be installed out of the lock chamber and into the vacuum vessel of the cryostat;
flooding and removing the lock chamber; and
coupling connections of an external cooling circuit to the NMR probe.

Assignees

• Bruker Biospin Ag

Inventors

• Schauwecker Robert
• Hinderer Joerg

Classifications

• G01R33/3815

  with superconducting coils, e.g. power supply therefor · CPC title

• G01R33/3804 Primary

  Additional hardware for cooling or heating of the magnet assembly, for housing a cooled or heated part of the magnet assembly or for temperature control of the magnet assembly · CPC title

• G01R33/34023

  Superconducting RF coils · CPC title

• G01R33/3403

  Means for cooling of the RF coils, e.g. a refrigerator or a cooling vessel specially adapted for housing an RF coil · CPC title

• G01R33/34015

  Temperature-controlled RF coils · CPC title