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CN-121985465-A - Multifunctional thin-wall vacuum chamber and extremely high vacuum obtaining method thereof

CN121985465ACN 121985465 ACN121985465 ACN 121985465ACN-121985465-A

Abstract

The invention relates to the technical field of accelerators, in particular to a multifunctional thin-wall vacuum chamber and an extremely high vacuum obtaining method thereof. The thin-wall vacuum chamber comprises a thin-wall cavity body, heat conducting structures and a refrigerating structure, wherein the cross sections of any positions of the thin-wall cavity body in the extending direction are consistent, the heat conducting structures are uniformly distributed on the outer surface of the thin-wall cavity body, the refrigerating structure is detachably connected with the heat conducting structures, the refrigerating structure comprises a first cooling pipe and a second cooling pipe which are symmetrically distributed on two sides of the thin-wall cavity body, the first end of the first cooling pipe is connected with the first end of the second cooling pipe, and the second end of the first cooling pipe and the second end of the second cooling pipe are respectively used as an inlet and an outlet of cooling liquid and are used for enabling the cooling liquid to flow along a set path on the outer side of the thin-wall cavity body. According to the invention, by arranging the detachable refrigeration structure, the thin-wall vacuum chamber can adapt to two processes of high-temperature baking and degassing and low-temperature liquid helium cooling, and the ultimate vacuum degree of the system is improved.

Inventors

  • XIE WENJUN
  • WAN YAPENG
  • Wei Ningfei
  • LI CHANGCHUN
  • ZHU XIAORONG
  • ZHANG RENPING
  • Zhong Kuangxia
  • MENG JUN
  • YANG JIANCHENG
  • LUO CHENG
  • CHAI ZHEN
  • YANG WEISHUN
  • LIU JIANLONG
  • JIAO JIQIANG
  • LIN XIAOJIAN

Assignees

  • 中国科学院近代物理研究所

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. A multi-functional thin-walled vacuum chamber, comprising: the thin-wall cavity (100), the cross section of any position of the thin-wall cavity (100) in the extending direction is consistent; The heat conducting structures (200) are uniformly distributed on the outer surface of the thin-wall cavity (100); A refrigeration structure (300) detachably connected to the heat-conducting structure (200); The refrigeration structure (300) comprises a first cooling pipe (310) and a second cooling pipe (320) which are symmetrically distributed on two sides of the thin-wall cavity (100); The first end of the first cooling pipe (310) is connected with the first end of the second cooling pipe (320), and the second end of the first cooling pipe (310) and the second end of the second cooling pipe (320) are respectively used as an inlet and an outlet of cooling liquid and are used for enabling the cooling liquid to flow along a set path outside the thin-wall cavity (100).
  2. 2. The multi-functional, thin-walled vacuum chamber according to claim 1, characterized in that the thermally conductive structure (200) comprises: A reinforcing rib (210) which is provided in a plate-like structure having a through hole in the middle; The reinforcing rib (210) is provided with a clamping groove (211), and an opening of the clamping groove (211) is positioned at the peripheral edge of the reinforcing rib (210) and used for installing the first cooling pipe (310) or the second cooling pipe (320).
  3. 3. The multifunctional thin-wall vacuum chamber according to claim 2, wherein a plurality of the reinforcing ribs (210) are sleeved on the thin-wall cavity (100), and the distance between every two adjacent reinforcing ribs (210) is 15mm to 22 mm.
  4. 4. A multi-functional thin-walled vacuum chamber according to claim 2 or 3, characterized in that the thermally conductive structure (200) further comprises: And a flexible heat conductive sheet (220) mounted on the outer peripheral edge of the reinforcing rib (210) for abutting against the iron yoke of the magnet to keep the heat conductive path continuous.
  5. 5. The multi-functional thin-walled vacuum chamber according to claim 4, characterized in that the flexible thermally conductive sheet (220) comprises: a base body (221) provided with a groove with a trapezoid cross section, wherein the width of the notch of the groove is smaller than the width of the bottom of the groove; A guide arc (222) provided at a notch edge of the groove to facilitate assembly; And a heat-conducting fin (223) disposed outside the base body (221) and extending along a bottom edge of the groove.
  6. 6. The multi-functional thin-walled vacuum chamber according to claim 5, characterized in that the flexible thermally conductive sheet (220) is made of an oxygen-free copper sheet having a thickness of between 0.1 and 0.3 mm.
  7. 7. A method for obtaining extremely high vacuum, characterized by being applied to a multifunctional thin-wall vacuum chamber according to any one of claims 1 to 6, comprising the following steps: pretreating a thin-wall vacuum chamber; Carrying out high-temperature baking and degassing on the thin-wall cavity (100); the thin-walled cavity (100) is cooled using a cooling structure (300).
  8. 8. The method of obtaining very high vacuum according to claim 7, wherein said pre-treating the thin-walled vacuum chamber comprises: Dismantling a refrigeration structure (300) connected with the thin-walled cavity (100); wrapping the thin-walled cavity (100) with a baking sleeve and connecting the sensor, the baking line and the control system; And adjusting the supporting device of the thin-wall vacuum chamber so as to provide a displacement space for the expansion and contraction of the thin-wall cavity (100).
  9. 9. The method of obtaining very high vacuum according to claim 8, wherein said high temperature bake out deaeration of the thin walled cavity (100) comprises: Coarse pumping and leakage detection are carried out on the thin-wall cavity (100); heating the thin-walled cavity (100) to 250-300 ℃ at a rate of 0.5 ℃ per minute, and preserving heat for 40-48 hours; In the heat preservation stage, a sputtering ion pump and a titanium sublimation pump are sequentially started, the titanium sublimation pump is provided with a plurality of titanium wires, and the titanium wires for degassing are switched every 2 hours; after the baking is finished, when the temperature is reduced to 180-190 ℃, the titanium sublimation pump is controlled to perform primary sublimation treatment at 48A current for 3 minutes, and then the rough pumping valve is closed.
  10. 10. The method of obtaining very high vacuum according to claim 9, wherein said cooling the thin-walled cavity (100) using a refrigeration structure (300) comprises: mounting the first cooling tube (310) and the second cooling tube (320) to the thermally conductive structure (200) and connecting the two with a straight-through ferrule (330); Low-flow liquid helium is introduced into the first cooling pipe (310) and the second cooling pipe (320), the thin-wall cavity (100) is slowly pre-cooled, the cooling rate of the thin-wall cavity (100) is controlled to be between 1K/min and 2K/min, and the thin-wall cavity (100) is kept for 20-40 minutes when the temperature of the thin-wall cavity (100) is reduced to the target temperature; gradually increasing the flow of liquid helium and reducing the temperature of the thin-wall cavity (100) to below 15K.

Description

Multifunctional thin-wall vacuum chamber and extremely high vacuum obtaining method thereof Technical Field The invention relates to the technical field of accelerators, in particular to a multifunctional thin-wall vacuum chamber and an extremely high vacuum obtaining method thereof. Background As heavy ion accelerators move toward higher energies, higher fluences and higher beam powers, superconducting fast-cycling accelerators become one of the main directions of future development. In the design of the vacuum cavity of the magnetic element of the device, the design needs to meet the following two points that firstly, a vacuum chamber with a thin-wall structure is adopted to inhibit the eddy current effect caused by a rapidly-changing magnetic field, and secondly, the dynamic temperature of the vacuum chamber is controlled below 15K so that the inner wall of the vacuum chamber plays a role of a low-temperature adsorption pump. In order to meet the requirements of a low-temperature extremely high vacuum system, two processes of high-temperature baking and degassing and low-temperature liquid helium cooling are needed to be implemented on the thin-wall vacuum chamber. However, the conventional thin-wall vacuum chamber is not provided with a cooling pipeline, cannot be directly used for a low-temperature extremely high vacuum system, can only be used for a normal-temperature extremely high vacuum system, and obtains the required vacuum degree through high-temperature online baking. If the cooling system is simply integrated with the conventional thin-wall vacuum chamber, structural restriction is generated because the cooling system cannot withstand high-temperature baking for a long time, so that the thin-wall vacuum chamber of the integrated cooling system cannot implement thorough high-temperature baking and degassing, and therefore gas adsorbed on the inner surface of the thin-wall vacuum chamber cannot be thoroughly removed, further improvement of extreme vacuum is limited, dynamic vacuum stability of the superconducting accelerator in high-current strong and high-cluster power operation is seriously affected, and the method becomes a key technical bottleneck for further improving system performance. Disclosure of Invention The present invention aims to solve the technical problems existing in the related art. Therefore, the invention provides a multifunctional thin-wall vacuum chamber and an extremely high vacuum obtaining method thereof, which are used for solving the problem that the structure of the traditional thin-wall vacuum chamber cannot be simultaneously suitable for two processes of high-temperature baking and degassing and low-temperature liquid helium cooling, and achieving the purposes of optimizing the structure of the thin-wall vacuum chamber and improving the ultimate vacuum degree and dynamic vacuum stability of a system. In a first aspect, the present invention provides a multi-functional thin-walled vacuum chamber comprising: The cross section of any position of the thin-wall cavity in the extending direction is consistent; The heat conducting structures are uniformly distributed on the outer surface of the thin-wall cavity; the refrigeration structure is detachably connected with the heat conduction structure; The refrigerating structure comprises a first cooling pipe and a second cooling pipe which are symmetrically distributed on two sides of the thin-wall cavity; The first end of the first cooling pipe is connected with the first end of the second cooling pipe, and the second end of the first cooling pipe and the second end of the second cooling pipe are respectively used as an inlet and an outlet of cooling liquid and are used for enabling the cooling liquid to flow along a set path outside the thin-wall cavity. According to the invention, the heat conduction structure comprises: the reinforcing ribs are arranged in a plate-shaped structure with a through hole in the middle; the reinforcing rib is provided with a clamping groove, and an opening of the clamping groove is positioned at the peripheral edge of the reinforcing rib and used for installing the first cooling pipe or the second cooling pipe. According to the multifunctional thin-wall vacuum chamber provided by the invention, the thin-wall cavity is sleeved with the plurality of reinforcing ribs, and the distance between every two adjacent reinforcing ribs is 15-22 mm. According to the multifunctional thin-wall vacuum chamber provided by the invention, the heat conduction structure further comprises: And the flexible heat conducting sheet is arranged at the peripheral edge of the reinforcing rib and is used for abutting against the iron yoke of the magnet so as to keep the heat conduction path continuous. According to the present invention, there is provided a multifunctional thin-wall vacuum chamber, the flexible heat conductive sheet comprising: The base body is provided with a groove with a trapezoid cross section, and