CN115248456B

CN115248456B - He-3 tube detector

Info

Publication number: CN115248456B
Application number: CN202210726650.9A
Authority: CN
Inventors: 杜畅通; 王学武; 洪伟航; 宫辉; 吴华锐
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2024-05-24
Anticipated expiration: 2042-06-23
Also published as: CN115248456A

Abstract

The invention relates to a He-3 tube detector, comprising: a sealed chamber for housing an electronics system; the plurality of He-3 tubes are arranged on the back plate of the sealed cavity in an array, wherein each He-3 tube is fixed on the back plate of the sealed cavity by a plurality of clamping grooves, and positioning holes penetrating through the back plate of the sealed cavity are arranged at positions corresponding to two ends of each He-3 tube; and the two ends of each He-3 pipe are respectively provided with an elbow structure, the elbow structure consists of a first pipe section, a second pipe section and a corrugated pipe section connected with the first pipe section, the free end of the first pipe section of the elbow structure is welded with the corresponding He-3 pipe, the free end of the second pipe section protrudes into the sealing cavity through a positioning hole corresponding to the corresponding He-3 pipe, and vacuum sealing relative to the sealing cavity is realized in a radial sealing mode in the positioning hole protruding into the elbow structure.

Description

He-3 tube detector

Technical Field

The invention relates to a He-3 tube detector.

Background

The He-3 tube detector is a large area neutron detector for measuring scattered neutrons. He-3 tube detectors typically choose to use either horizontal or vertical rows of He-3 tubes to form an array detector array. The inter-tube gap of the He-3 tube array may deteriorate the position resolution in the Y direction. There is a particularly high requirement for the accuracy of array mounting of He-3 tubes.

The He-3 tube is usually a straight tube-shaped pressure vessel of, for example, 8mm in outside diameter, in which a pressure of 10atm is filled, and a signal line is drawn at each end of the He-3 tube. Because the further the weld joint is from the wire of the He-3 tube, the better the bend welding is, and if necessary, the welded hollow tube sections are also included as He-3 extension tubes at both ends of the He-3 tube, with the wire being in the hollow tube. The He-3 extension tube and the He-3 tube body have better coaxiality.

The He-3 tube detector is generally in a vacuum environment, a sealed cavity is usually designed in a vacuum tank in consideration of the sparking phenomenon of the electronic system in the vacuum environment, the electronic system is placed in the sealed cavity, and the He-3 tube detector is placed in the vacuum environment outside the sealed cavity. The He-3 tube is made as close to the electronics system as possible in view of the cable length and other factors. A fixing clamping groove of the He-3 tube is designed on the outer wall of the sealing chamber, and the detector is fixed on the outer wall of the sealing chamber. The sealed cavity and the He-3 tube array are integrally arranged in a vacuum environment, the sealed cavity is designed with a quick-connection flange, and the quick-connection flange is communicated with the atmosphere through a vacuum pipeline, so that the high-voltage lead part of the detector and the electronic system can be packaged in a normal-pressure environment, and the stable operation and good heat dissipation of the system are ensured.

The connection between the He-3 tube detector and the electronic system generally adopts two mounting schemes, namely, the electronic connection device is used for vacuum sealing, one end of the He-3 tube detector is connected with the electronic connection device, the other end of the He-3 tube detector is connected with the electronic connection device and the electric main board, and the He-3 tube detector of the Chinese Mianyang research pile (CMRR) adopts the design. And secondly, vacuum sealing is carried out by using a mode of welding a metal bent pipe, one end of the metal bent pipe is welded at the end head of the He-3 pipe to realize partial vacuum sealing, the other end of the metal bent pipe is arranged on the vacuum chamber, the radial sealing mode is adopted by matching with an O-shaped ring to realize vacuum sealing, and a lead wire of the He-3 pipe is directly connected into the vacuum chamber through the welded metal bent pipe and is connected with an electronic system. This scheme was first proposed and used in China by the China spallation source (CSNS). The high-pressure protection joint is welded to the He-3 tube to prevent the ignition of the He-3 tube under high-pressure vacuum. However, in order to ensure the mounting straightness of the He-3 tube, a high requirement for the welding straightness is required.

In practical application, the spectrometer is not considered from the connection of the He-3 tube detector and the electronic system, but the vacuum degree in the scattering cavity is controlled to be high in vacuum so as to increase the voltage, and the ignition problem of the electronic system in a vacuum environment is avoided by the way of interlocking and not increasing the voltage under the vacuum degree with poor intermediate insulation.

The first scheme has the advantages that the He-3 tube is not subjected to secondary processing, the existing electronic connecting device is directly purchased to complete vacuum isolation, the installation accuracy is mainly determined by the accuracy of the tube and the accuracy of the clamping groove, and the implementation is easier. The first disadvantage of the scheme is that the performance of purchasing the electronic sealing device needs to be verified according to the actual working condition. Part of cables are exposed in vacuum between the purchased electronic connecting device and He-3, special treatment is needed for the cables, the problem of ignition is avoided, and the risk is high in engineering implementation.

The second scheme has the advantages that the cost of the welded metal tube is relatively low, the lead wire of the He-3 tube is directly connected with the vacuum chamber through the bent tube and is electrically connected with the vacuum chamber, the risk of ignition is low, and the risk in engineering is lower. The second scheme has the disadvantage that the welding precision between the bent pipe and the He-3 pipe determines the installation precision of the He-3 pipe array. Because of the high requirement on the tube gap of the He-3 tube detector, the installation precision of the He-3 tube is high, and the two ends of the bent tube are required to be guaranteed to have high flatness when the bent tube is welded, and the connecting part of the He-3 tube and the body of the He-3 tube in the bent tube have high coaxiality. Poor welding and mounting accuracy can lead to stress concentration at a welded junction of the bent pipe, damage to the welded junction can be caused, vacuum is problematic, and even more, stress concentration is transmitted to the He-3 pipe body, so that the He-3 pipe is problematic, and the pipe body is scrapped most seriously.

Therefore, the technical problem to be solved by the present invention is to provide a He-3 tube probe, which can provide a firm and reliable He-3 tube lead connection mode with simple and convenient processing and a reliable vacuum isolation mode between the He-3 tube and the sealed cavity, and at the same time avoid stress concentration which may affect welding quality or be transferred to the He-3 tube body.

Disclosure of Invention

In order to solve the technical problems, the present invention provides a He-3 tube detector, comprising: a sealed chamber for housing an electronics system; the device comprises a plurality of He-3 tubes, a plurality of welding grooves and a plurality of positioning holes, wherein the He-3 tubes are arranged on a back plate of the sealing chamber in an array manner, and two ends of the He-3 tubes respectively comprise welded He-3 extension tubes when necessary, each He-3 tube is fixed on the back plate of the sealing chamber through the plurality of clamping grooves, and the positioning holes penetrating through the back plate of the sealing chamber are arranged at positions corresponding to two ends of each He-3 tube; and the two ends of each He-3 pipe are respectively provided with an elbow structure, the elbow structure consists of a first pipe section, a second pipe section and a corrugated pipe section for connecting the first pipe section and the second pipe section, the free end of the first pipe section of the elbow structure and the corresponding He-3 pipe are welded with each other, and the free end of the second pipe section protrudes into the sealing cavity through the positioning hole corresponding to the corresponding He-3 pipe, wherein the inside of the positioning hole protruding into the elbow structure is sealed in a radial sealing mode.

All parts of the bent pipe structure can be automatically processed and welded into a whole, then the welding leak rate is independently checked, and the qualified part is welded with the He-3 pipe, so that the quick judgment on whether the leak rate meets the use requirement after the whole welding of the He-3 pipe is realized.

According to one embodiment of the invention, the first tube section of the tube bending structure is a straight tube section and the second tube section is a tube bending section. Alternatively, the first tube section of the tube bending structure can also be designed as a tube bending section and the second tube section as a straight tube section. It is also possible to design the bellows segment to be curved and to design both the first and the second segment of the elbow structure as straight segments or as elbow segments. In other words, the bent pipe structure may be connected with the He-3 pipe by the straight pipe section, inserted into the positioning hole by the bent pipe section, or in an alternative implementation form, connected with the He-3 pipe by the bent pipe section, inserted into the positioning hole by the straight pipe section, or two straight pipe sections are provided for the bent pipe structure to be connected with the He-3 pipe and inserted into the positioning hole respectively, at this time, the turning connection between the He-3 pipe and the positioning hole is achieved by using the bending shape of the bellows. In either connection, the bellows segment between the straight and curved segments provides a certain amount of misalignment adjustment. When vacuum sealing is carried out, the bellows can furthest reduce the transmission of stress to the pipe body caused by insufficient early-stage accumulation precision. The main body part of the He-3 tube is protected to the maximum extent, the damage caused by stress is avoided, the risk is reduced, and the cost is reduced.

Preferably, the clamping groove and the positioning hole corresponding to each He-3 pipe are processed in the same processing procedure. This allows the He-3 tube to be positioned with higher accuracy without generating stress.

The sealed chamber is provided with a quick-connection flange which is communicated with the atmosphere through a vacuum pipeline.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. Other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

Embodiments of the present invention are explained in detail below with reference to the drawings. In the drawings:

FIG. 1 schematically illustrates a longitudinal cross-sectional view of a He-3 tube detector according to the present invention;

FIG. 2 schematically illustrates a top view of a He-3 tube detector according to the present invention;

FIG. 3 schematically illustrates a partial enlarged view of FIG. 2;

FIG. 4 schematically illustrates a partial enlarged view of a longitudinal section of the He-3 tube probe according to the present invention;

FIG. 5 schematically shows a longitudinal cross-sectional view of an elbow structure of the He-3 tube probe according to the present invention.

The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate and together with the description serve to explain the application, and not to limit the application. In the drawings, the same technical features are denoted by the same reference numerals.

Detailed Description

FIG. 1 schematically shows a longitudinal cross-sectional view of a He-3 tube probe 10 according to the present invention. The He-3 tube probe 10 includes a sealed chamber 110 for accommodating the electronic system 120 and a plurality of He-3 tubes 130 arranged in an array on a back plate of the sealed chamber, and an elbow structure 170 respectively provided for both ends of each He-3 tube 130.

Each of the He-3 tubes 130 is fixed to the back plate of the sealed chamber 110 by a plurality of clamping grooves 150, and positioning holes 160 penetrating the back plate of the sealed chamber are arranged at positions corresponding to both ends of each of the He-3 tubes 130.

Fig. 5 schematically illustrates a longitudinal cross-sectional view of an elbow structure 170 of the He-3 tube probe 10 according to the present invention. The He-3 tube 130 is connected (if necessary, via He-3 extension tubes 140 at both ends) to the tube bending structure 170, and the tube bending structure 170 is composed of a first tube section 171 (here, a tube bending section), a second tube section 173 (here, a straight tube section), and a bellows section 172 connecting the first tube section 171 and the second tube section 173. The free end of the first tube section 171 is welded to the corresponding He-3 tube 130 (He-3 extension tube 140 if necessary). The free end of the second tube segment 173 then protrudes into the sealed chamber 110 via the locating hole 160 corresponding to the corresponding He-3 tube 130. A vacuum seal is achieved in a radial seal within the locating hole 160 into which the elbow structure 170 protrudes with respect to the interior of the sealed chamber 110. A radial seal is disposed between the locating hole 160 of the He-3 tube 130 and the second tube segment 173 to close the sealed chamber 110. Bellows segment 172 has a size comparable to the tube diameter of He-3 tube 130.

The clamping groove 150 and the positioning hole 160 corresponding to each He-3 tube 130 are processed in the same processing step. This allows the He-3 tube 130 to be positioned with higher accuracy. The bellows segment 172 of the flexure mechanism 170 provides a certain position adjustment capability so that the stress of the second tube segment 173 is not conducted to the He-3 tube 130.

Also shown in fig. 1 is a quick-connect flange 180 of the sealed chamber 110, the sealed chamber 110 being in communication with the atmosphere via a vacuum line by means of the quick-connect flange 180. The sealed chamber 110 may be evacuated as desired.

Fig. 2 schematically shows a top view of the He-3 tube probe 10 according to the present invention. Fig. 3 is a partially enlarged view of fig. 2. They schematically illustrate He-3 tubes 130 arranged in an array on the back plate of the sealed chamber 110 and the curved structures 170 at both ends thereof.

FIG. 4 schematically shows a partial enlarged view of a longitudinal section of the He-3 tube probe 10 according to the present invention. The curved structure 170 extends into the sealed cavity 110 through the locating hole 160 with a second tube segment 173. The sealed cavity 110 is communicated with the atmosphere through a vacuum channel by a quick-connection flange 180 to realize the atmospheric environment, and can be vacuumized.

In other embodiments, different straight tube sections/bend sections may be used to form the bend described above.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: numerous variations, changes, substitutions, variations and combinations of the embodiments are possible without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

List of reference numerals

10 He-3 tube detector

110. Sealed chamber

120. An electronics system;

130 He-3 tube

140 He-3 extension tube

150. Clamping groove

160. Positioning holes;

170. Bent pipe structure

171. First pipe section

172. Corrugated pipe section

173. Second pipe section

180. And (5) quickly connecting the flange.

Claims

1. A He-3 tube detector (10), characterized in that the He-3 tube detector (10) comprises:

A sealed chamber (110) for housing an electronics system (120);

A plurality of He-3 tubes (130) arranged in an array on the back plate of the sealed chamber (110), wherein each He-3 tube (130) is fixed by a plurality of clamping grooves (150) on the back plate of the sealed chamber (110), and positioning holes (160) penetrating the back plate of the sealed chamber (110) are arranged at positions corresponding to both ends of each He-3 tube (130); and

A bent pipe structure (170) respectively arranged at two ends of each He-3 pipe (130), the bent pipe structure is composed of a first pipe section (171), a second pipe section (173) and a corrugated pipe section (172) for connecting the first pipe section and the second pipe section, the free end of the first pipe section of the bent pipe structure (170) is mutually welded with the corresponding He-3 pipe (130), the free end of the second pipe section is protruded into the sealing chamber (110) through the positioning hole (160) corresponding to the corresponding He-3 pipe (130),

Wherein a vacuum seal is achieved in a radial seal within the locating hole (160) into which the elbow structure (170) protrudes with respect to the inside of the sealed chamber (110).

2. The He-3 tube probe (10) of claim 1, wherein the first tube segment of the elbow structure (170) is a straight tube segment and the second tube segment is an elbow segment.

3. The He-3 tube probe (10) of claim 1, wherein the first tube segment of the elbow structure (170) is an elbow segment and the second tube segment is a straight tube segment.

4. The He-3 tube probe (10) of claim 1, wherein the first tube segment and the second tube segment of the elbow structure (170) are both straight tube segments or are both elbow tube segments, and the bellows segment (172) is curved.

5. The He-3 tube probe (10) according to any one of claims 2 to 4, wherein the clamping groove (150) and the positioning hole (160) corresponding to each He-3 tube (130) are processed in the same processing process.

6. He-3 tube detector (10) according to any one of claims 1 to 4, characterized in that the sealed chamber (110) is provided with a quick-connect flange (180) which communicates with the atmosphere through a vacuum conduit.