Cryostat arrangement with a vacuum container and an object to be cooled, with evacuable cavity

Patent metadata

Field	Value
Publication number	US-10101420-B2
Application number	US-201715710283-A
Country	US
Kind code	B2
Filing date	Sep 20, 2017
Priority date	Sep 20, 2016
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A cryostat arrangement ( 1 ), with a vacuum container ( 2 ) and an object ( 4 ) to be cooled, is provided, wherein the object ( 4 ) to be cooled is arranged inside the vacuum container ( 2 ) comprising a neck tube ( 8 ) leading to the object ( 4 ) to be cooled. A closed cavity ( 9 ) is formed around the cooling arm ( 10 ) of a cold head ( 11 ), wherein the cavity ( 9 ) in normal operation is filled at least partly with a first cryogenic fluid ( 34 ), and wherein a first thermal coupling component ( 15 ) is provided for the thermal coupling of the first cryogenic fluid ( 34 ) in the cavity ( 9 ) to the object ( 4 ) to be cooled. The cryostat arrangement ( 1 ) further comprises a pump device ( 14 ), to which the cavity ( 9 ) is connected, and with which the cavity ( 9 ) is configured to be evacuated upon failure of the cooling function of the cold head ( 11 ). Various cryostat configurations are provided.

First claim

What is claimed is:

1. A cryostat comprising:
(a) a vacuum container; and
(b) an object to be cooled,
wherein the object to be cooled is arranged inside the vacuum container,
wherein the vacuum container further comprises a neck tube, leading to the object to be cooled,
wherein a cooling arm of a cold head is arranged at least partly in the neck tube,
wherein a closed cavity is formed around the cooling arm, being sealed off fluid-tight from the object to be cooled, and
wherein the cavity in normal operation is filled at least partly with a first cryogenic fluid;

(c) a first thermal coupling component for thermal coupling of the first cryogenic fluid in the cavity to the object to be cooled,
(d) a pump device, to which the cavity is connected, and with which the cavity is configured to be evacuated upon failure of the cooling function of the cold head; and
(e) a monitoring device, which monitors the cooling function of the cold head, and which is configured to automatically activate the pump device upon failure of the cooling function of the cold head, so that the cavity is evacuated.

2. The cryostat according to claim 1 , wherein the cooling arm of the cold head is arranged directly in the cavity.

3. The cryostat according to claim 2 , further comprising:
an outer enclosure of the cavity spaced apart from an inner wall of the neck tube, wherein an intermediate space is formed between the inner wall of the neck tube and the enclosure, open toward the object to be cooled, and
wherein the object to be cooled toward which the intermediate space is open is a cryocontainer, filled at least partly with a second cryogenic fluid, and wherein the intermediate space comprises a feed line for the second cryogenic fluid to be introduced or returned.

4. The cryostat according to claim 3 , wherein the cold head including the enclosure of the cavity is mounted to be mechanically decoupled from the rest of the cryostat including the object to be cooled, further comprising a flexible membrane, which seals off the intermediate space from the surroundings.

5. The cryostat according to claim 1 , wherein the cooling arm is arranged directly in a cooling arm container, and the cavity is formed around the cooling arm container such that the cooling arm container is sealed off fluid-tight from the cavity, and further comprising: a second thermal coupling means, for the thermal coupling of the first cryogenic fluid in the cavity to the interior of the cooling arm container, wherein a third cryogenic fluid is arranged in the cooling arm container.

6. The cryostat according to claim 5 , wherein the cold head is mounted to be mechanically decoupled from a wall of the cooling arm container and the rest of the cryostat including the object to be cooled, and wherein a flexible membrane spans an annular gap between the wall of the cooling arm container and the cold head and seals off the interior of the cooling arm container from the surroundings.

7. The cryostat according to claim 1 , wherein the object to be cooled is a cryocontainer, and an outer enclosure of the cavity protrudes into an upper region of the cryocontainer.

8. The cryostat according to claim 7 , wherein a first cryogenic liquid is arranged in the cavity in normal operation, a second cryogenic liquid is arranged in the cryocontainer, and the outer enclosure of the cavity is submerged in the second cryogenic liquid in the cryocontainer.

9. The cryostat according to claim 2 , wherein a first cryogenic liquid is arranged in the cavity in normal operation, a second cryogenic liquid is arranged in a cryocontainer, and an outer enclosure of the cavity is submerged in the second cryogenic liquid in the cryocontainer, and wherein at least a lower cold stage of the cooling arm is submerged in the first cryogenic liquid in the cavity.

10. The cryostat according to claim 5 , wherein a first cryogenic liquid is arranged in the cavity in normal operation, a second cryogenic liquid is arranged in a cryocontainer, and an outer enclosure of the cavity is submerged in the second cryogenic liquid in the cryocontainer, and wherein the cooling arm container is submerged in the first cryogenic liquid in the cavity, and a third cryogenic liquid is arranged in the cooling arm container, in which at least a lower cold stage of the cooling arm is submerged.

11. The cryostat according to claim 1 , wherein the pump device is configured as a sorption pump, whose pumping cold surfaces are thermally coupled to the object to be cooled, and wherein a connection line extends from the cavity to the pumping cold surfaces entirely inside the vacuum container.

12. The cryostat according to claim 1 , wherein the object to be cooled is a cryocontainer, which is filled at least partly with a second cryogenic fluid, and wherein a superconducting magnet coil system is arranged in the cryocontainer.

13. The cryostat according to claim 1 , wherein the object to be cooled is a superconducting magnet coil system, which is arranged directly in the vacuum container.

14. A method for operating a cryostat comprising:
providing a first thermal coupling component for thermal coupling of a first cryogenic fluid in a cavity to an object to be cooled,
wherein the object to be cooled is arranged in a vacuum container comprising a neck tube, the neck tube leading to the object to be cooled,
wherein a cooling arm of a cold head is arranged at least partly in the neck tube,
wherein a closed cavity is formed around the cooling arm, sealed off fluid-tight from the object to be cooled;
operating the cryostat under normal operation with an at least partial filling of the cavity with the first cryogenic fluid to cool the object inside the vacuum container; and
evacuating the cavity upon failure of the cooling function of the cold head.

15. A method according to claim 14 , wherein the object to be cooled is a superconducting magnet coil system or a cryocontainer.

Assignees

• Bruker Biospin Gmbh

Inventors

• Wikus Patrick
• Bonn Steffen

Classifications

• F25B2500/06

  Damage · CPC title

• F25D19/006 Primary

  Thermal coupling structure or interface · CPC title

• F17C2223/0161

  cryogenic, e.g. LNG, GNL, PLNG · CPC title

• F25D19/00

  Arrangement or mounting of refrigeration units with respect to devices {or objects to be refrigerated, e.g. infrared detectors} · CPC title

• F25B49/005

  of safety devices (F25B49/02 and F25B49/04 take precedence) · CPC title