Ultraviolet single-photon detector with protection structure and detection system

Abstract

The invention provides an ultraviolet single-photon detector with a protection structure and a detection system, which are used for solving the problems that a multi-channel electron multiplier and an anode in an existing ultraviolet single-photon detector are both arranged in a vacuum tube shell, and the distance between the last micro-channel plate and the anode cannot be precisely designed to be 1-5mm during installation; and a conventional micro-channel plate is not provided with a protection device and a shockproof function. According to the ultraviolet single-photon detector with the protection structure provided by the invention, the multi-channel electron multiplier is subjected to structural design again, the first groove and the second groove which are communicated are formed in the bottom plate, the plurality of micro-channel plates are pressed and fixed in the first groove through the pressing ring and the protection ring, the anode is arranged in the second groove, and the multi-channel electron multiplier is fixed in the first groove through the protection ring. The distance between the multi-channel electron multiplier and the anode is accurately adjusted, diffusion of electron cloud clusters is effectively avoided, the spatial resolution is improved, and high-precision detection is achieved.

Description

Technical Field

[0001] The invention relates to a detector, and in particular to an ultraviolet single-photon detector with a protection structure and a detection system. Background Art

[0002] At present, multi-channel electron multipliers are widely used in ultraviolet single-photon detectors. Multi-channel electron multipliers are usually composed of multiple microchannel plates with the same structure. Each microchannel plate includes a channel hole, a channel wall, an input electrode and an output electrode. Among them, a certain DC working voltage is applied between the input electrode and the output electrode. Its function is to establish an electric field distribution from low to high on the inner wall of the channel of the multi-channel electron multiplier, so that the electrons move in the channel and have enough kinetic energy to bombard the inner wall of the channel to produce secondary electrons. The electrons input from each microchannel plate undergo multiple secondary electron multiplications in the channel. When they are output from the output end, the number of electrons is multiplied to form an electron cloud, which is then hit on the anode. The electron cloud is electron multiplied by multiple microchannel plates, which is beneficial to improve the resolution of the detector.

[0003] In existing ultraviolet single-photon detectors, the multi-channel electron multiplier and the anode are both set in a vacuum tube shell. Since the processing error of the multi-channel electron multiplier and the anode is on the order of 1-2mm, and the design structure is very complex, it is impossible to accurately design the distance between the last microchannel plate and the anode to 1-5mm during installation. The distance deviation between the microchannel plate and the anode will cause the electron cloud to diffuse, thereby causing imaging distortion and affecting spatial resolution. In addition, the traditional microchannel plate does not have a protective device and shockproof function, and is easily damaged during use, increasing the cost of use. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems that in the existing ultraviolet single-photon detector, the multi-channel electron multiplier and the anode are both arranged in a vacuum tube shell, and the distance between the last microchannel plate and the anode cannot be accurately designed to 1-5mm during installation, thereby causing imaging distortion, and the traditional microchannel plate does not have a protective device and shockproof function, and to provide an ultraviolet single-photon detector and a detection system with a protective structure.

[0005] In order to achieve the above purpose, the technical solution provided by the present invention is as follows:

[0006] An ultraviolet single-photon detector with a protective structure comprises a vacuum tube shell, an optical window arranged at the front end of the vacuum tube shell, a photocathode, a multi-channel electron multiplier and an anode; the special features of the detector are:

[0007] The photocathode and the multi-channel electron multiplier are arranged in sequence in the vacuum tube shell from front to back;

[0008] The multi-channel electron multiplier comprises a base plate, M microchannel plates, M+1 first metal gaskets, a guard ring and a pressure ring, M≥2;

[0009] The bottom plate is a columnar structure, which is transversely fixed in the vacuum tube shell; a first groove adapted to the outer diameter of the microchannel plate is axially opened at the front end of the bottom plate, and a second groove adapted to the outer diameter of the anode is axially opened at the rear end of the bottom plate, and the first groove is coaxially connected with the second groove;

[0010] The first metal gasket and the protection ring are both annular structures with the same outer diameter as the microchannel plate;

[0011] M+1 first metal gaskets and M microchannel plates are alternately arranged in the first groove from front to back;

[0012] The protection ring is arranged in the first groove and is located on the outside of the first metal gasket at the front end; the pressure ring is arranged on the outside of the protection ring and is fixedly connected to the bottom plate on all sides, and is used to press and fix the M+1 first metal gaskets and the M microchannel plates in the first groove through the pressure ring and the protection ring;

[0013] The anode is arranged in the second groove, and a second metal gasket is arranged on the anode back plate for grounding.

[0014] Furthermore, the protective ring is made of rubber.

[0015] Furthermore, the first metal gasket is made of aluminum alloy.

[0016] Furthermore, the anode is a resistor anode, or a cross-line anode, or a wedge-shaped anode, or a delay line anode.

[0017] Furthermore, the multi-channel electron multiplier also includes an adapter and N+1 connecting wires;

[0018] The base plate is provided with N+1 high-voltage interfaces, one end of the N+1 connecting wires is connected to the adapter, and the other end is connected to N+1 first metal gaskets through the corresponding high-voltage interface, so as to apply voltage to each first metal gasket through the connecting wires.

[0019] Further, the multi-channel electron multiplier also includes four fastening bolts;

[0020] The pressure ring is provided with four lugs extending outwards in the circumferential direction, and each of the four lugs is provided with a through hole;

[0021] The bottom plate is provided with threaded holes at positions corresponding to the four lug through holes;

[0022] The four fastening bolts pass through the through holes on the corresponding lugs and are threadedly connected with the corresponding threaded holes.

[0023] In addition, the present invention also provides an ultraviolet single photon detection system, which is special in that it includes the above-mentioned ultraviolet single photon detector with a protective structure and an electronic readout circuit;

[0024] The anode is provided with a connector for leading the signal to the electronic readout circuit.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides an ultraviolet single-photon detector with a protective structure. The multi-channel electron multiplier is redesigned, and a first groove and a second groove that are connected are opened on the bottom plate. A plurality of microchannel plates are pressed and fixed in the first groove by a pressure ring and a protective ring, and the anode is arranged in the second groove, so that the distance between the multi-channel electron multiplier and the anode can be accurately adjusted, so that the distance between the last microchannel plate in the multi-channel electron multiplier and the anode can reach 1-3mm, which effectively avoids the diffusion of electron clouds, improves the spatial resolution, and achieves high-precision detection; in addition, compared with the traditional multi-channel electron multiplier, which connects a series of voltage-dividing resistors between the high-voltage power supply and the microchannel plate to extract and add high-voltage signals, the present invention cleverly adds a first metal gasket between two adjacent microchannel plates of the multi-channel electron multiplier, which not only realizes the accurate adjustment of the distance between the multi-channel electron multiplier and the anode, but also can realize the extraction and addition of high-voltage signals through the first metal gasket, avoiding the introduction of a series of voltage-dividing resistors.

[0027] 2. In the multi-channel electron multiplier of the ultraviolet single-photon detector provided by the present invention, the location of the anode can ensure the effective inflow of electrons and avoid the complex grounding structure when the anode is set inside the vacuum tube shell.

[0028] 3. The present invention provides an ultraviolet single-photon detector with a protective structure, which prevents the edge of the microchannel plate from being worn by a protective ring. At the same time, by providing a pressure ring, when the detector collides or falls, the surface of the microchannel plate will not touch the ground, which has a shock-absorbing effect on the microchannel plate, thereby extending the service life of the microchannel plate and reducing the cost of use.

[0029] 4. The present invention provides an ultraviolet single-photon detection system, which adopts the above-mentioned ultraviolet single-photon detector with a protective structure, and can directly lead the signal to the back-end electronic readout circuit through only one connector, thereby simplifying the structure of the detection system and ensuring a higher detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 An exploded view of a multi-channel electron multiplier in an embodiment of an ultraviolet single-photon detector with a protective structure of the present invention;

[0031] Figure 2 It is a left view of a multi-channel electron multiplier in an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the structure of the front end of the bottom plate of the multi-channel electron multiplier in an embodiment of the present invention;

[0033] Figure 4 This is a schematic structural diagram of the rear end of the bottom plate of the multi-channel electron multiplier in an embodiment of the present invention;

[0034] Figure 5 The figure is a schematic diagram of the installation structure of the bottom plate and the anode of the multi-channel electron multiplier in an embodiment of the ultraviolet single photon detection system of the present invention.

[0035] The specific reference numerals are as follows:

[0036] 1-base plate; 2-microchannel plate; 3-first metal gasket; 4-protection ring; 5-pressure ring; 6-high voltage interface; 7-anode; 8-first groove; 9-second groove; 10-second metal gasket; 11-connector. DETAILED DESCRIPTION

[0037] In order to make the advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] An ultraviolet single-photon detector with a protective structure comprises a vacuum tube shell, an optical window arranged at the front end of the vacuum tube shell, a photocathode, a multi-channel electron multiplier and an anode 7; the photocathode and the multi-channel electron multiplier are arranged in the vacuum tube shell in sequence from front to back.

[0039] The present invention focuses on the structural design of the multi-channel electron multiplier and the position design of the anode 7. Figure 1 , Figure 2 As shown, the multi-channel electron multiplier in this embodiment includes a base plate 1, two microchannel plates 2, three first metal gaskets 3, a protection ring 4, a pressure ring 5, an adapter and three connecting wires. The base plate 1 is an annular structure, which is radially arranged in the vacuum tube shell, and the outer wall of the base plate 1 is fixedly connected to the inner wall of the vacuum tube shell by screws. Figure 3 As shown, the front end of the bottom plate 1 is axially provided with a first groove 8 adapted to the outer diameter of the microchannel plate 2; Figure 4 As shown, a second groove 9 adapted to the outer diameter of the anode 7 is axially opened at the rear end of the bottom plate 1, and the first groove 8 is coaxially connected with the second groove 9.

[0040] The first metal gasket 3 is an annular structure with the same outer diameter as the microchannel plate 2, and its material is preferably aluminum alloy, which has good electrical conductivity, can lead out the signal, and add and take voltage, thereby improving the gain. In other embodiments of the present invention, the first metal gasket 3 can also be made of copper, stainless steel and other materials. The three first metal gaskets 3 and the two microchannel plates 2 are alternately arranged in the first groove 8 from front to back, that is, one first metal gasket 3 is arranged between the first microchannel plate 2 and the second microchannel plate 2, and the other two first metal gaskets 3 are respectively arranged at the front end of the first microchannel plate 2 and the rear end of the second microchannel plate 2, and the two microchannel plates 2 are supported and fixed as a whole by the three first metal gaskets 3. Three high-voltage interfaces 6 are provided on the base plate 1, one end of the three connecting wires is connected to the adapter, and the other end is connected to the three first metal gaskets 3 through the corresponding high-voltage interfaces 6, which are used to apply voltage to the three first metal gaskets 3 through the connecting wires. In this embodiment, a cathode high voltage interface is also provided on the bottom plate 1, and correspondingly, there is also a cathode connecting wire, one end of the cathode connecting wire is connected to the adapter, and the other end is connected to the photocathode through the cathode high voltage interface, so as to apply voltage to the photocathode through the cathode connecting wire. In the present invention, the number of microchannel plates 2 is set according to the gain requirement, the number of first metal gaskets 3 is set according to the number of microchannel plates 2, usually the number of microchannel plates 2 plus one, a first metal gasket 3 is set between two adjacent microchannel plates 2, and a first metal gasket 3 is respectively set at the front end of the first microchannel plate 2 and the rear end of the last microchannel plate 2.

[0041] The protection ring 4 is also an annular structure with the same outer diameter as the microchannel plate 2. It is arranged in the first groove 8 and is located on the outside of the first metal gasket 3 at the front end. The pressure ring 5 is arranged on the outside of the protection ring 4. Four lugs extending outward are arranged on the pressure ring 5 in the circumferential direction. Through holes are respectively provided on the four lugs. Threaded holes are respectively provided at the positions corresponding to the four lug through holes on the bottom plate 1. Four fastening bolts pass through the through holes on the corresponding lugs and are threadedly connected with the corresponding threaded holes, which are used to press and fix the protection ring 4, the three first metal gaskets 3 and the two microchannel plates 2 in the first groove 8 through the fixed connection between the pressure ring 5 and the bottom plate 1. Among them, the protection ring 4 is used to protect the microchannel plate 2 and play a buffering role on the microchannel plate 2 when vacuum is extracted to prevent it from being worn. The pressure ring 5 is used to fix the microchannel plate 2 in the first groove 8 by protection, which plays a shock absorbing role; the first metal gasket 3 is used to lead out and add high-voltage signals, and the structural design is simple. Specifically, when the pressure ring 5 is fixedly connected to the bottom plate 1, the diagonal lines are first tightened gradually with the tightening bolts. When the tightening bolts are tightened, the protection ring 4 is clamped in the pressure ring 5, so that the first metal gasket 3 and the microchannel plate 2 are fixed in the first groove 8. The protection ring 4 is preferably made of rubber material, which will not cause the protection ring 4 to deflect during the movement of the detector due to being too soft, thereby reducing the gain characteristics of the microchannel plate 2. In addition, the rubber material also has a certain friction force, which can play a certain fixing role.

[0042] In the present invention, the anode 7 is arranged in the second groove 9, and aluminum is selected as the substrate material of the anode 7. This design can well realize vacuum sealing and facilitate the replacement of the anode 7. At the same time, since the anode 7 is arranged in the second groove 9, that is, arranged outside the vacuum tube shell, a second metal gasket 10 can be directly placed on the back plate of the anode 7 as the ground of the anode 7, which can ensure the effective inflow of electrons and avoid the complex grounding structure set when the anode 7 is arranged inside the vacuum tube shell.

[0043] The structural design of the multi-channel electron multiplier of the present invention and the position design of the anode 7 can accurately adjust the distance between the multi-channel electron multiplier and the anode 7, so that the distance between the last microchannel plate 2 in the multi-channel electron multiplier and the anode 7 reaches 1-3 mm, effectively avoiding the diffusion of electron clouds, improving the spatial resolution, and realizing high-precision detection. At the same time, the signal is led out through the three first metal gaskets 3, and high voltage is added and taken between the microchannel plates 2 and the microchannel plates 2, and between the microchannel plates 2 and the anode 7. Moreover, this structure is not easily damaged, prolongs the use time, and reduces the use cost.

[0044] The present invention provides an ultraviolet single photon detection system, comprising the ultraviolet single photon detector with a protective structure and an electronic readout circuit; Figure 5As shown, a connector 11 is provided on the anode 7, and the signal generated by the ultraviolet single photon detector is received by the anode 7, and the anode 7 directly leads the signal to the electronic readout circuit at the back end through a connector 11. In the present invention, the anode 7 can be a resistor anode, a cross-line anode, a wedge-shaped anode, a delay line anode, etc.

[0045] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. For ordinary professional and technical personnel in the field, the specific technical solution recorded in the above embodiment can be modified, or some of the technical features therein can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution protected by the present invention.

Claims

1. An ultraviolet single-photon detector with a protective structure, comprising a vacuum tube shell, an optical window arranged at the front end of the vacuum tube shell, a photocathode, a multi-channel electron multiplier and an anode (7); characterized in that: The photocathode and the multi-channel electron multiplier are arranged in sequence in the vacuum tube shell from front to back; The multi-channel electron multiplier comprises a base plate (1), M microchannel plates (2), M+1 first metal gaskets (3), a protection ring (4) and a pressure ring (5), M≥2; The bottom plate (1) is a columnar structure, which is transversely fixed in the vacuum tube shell; a first groove (8) adapted to the outer diameter of the microchannel plate (2) is axially opened at the front end of the bottom plate (1), and a second groove (9) adapted to the outer diameter of the anode (7) is axially opened at the rear end of the bottom plate (1); the first groove (8) and the second groove (9) are coaxially connected; The first metal gasket (3) and the protection ring (4) are both annular structures having the same outer diameter as the microchannel plate (2); M+1 first metal gaskets (3) and M microchannel plates (2) are alternately arranged in the first groove (8) from front to back; The protective ring (4) is arranged in the first groove (8) and is located outside the first metal gasket (3) at the front end; the pressure ring (5) is arranged outside the protective ring (4) and is fixedly connected to the bottom plate (1) on all sides, and is used to press and fix M+1 first metal gaskets (3) and M microchannel plates (2) in the first groove (8) through the pressure ring (5) and the protective ring (4); The anode (7) is arranged in the second groove (9), and a second metal gasket (10) is arranged on the back plate of the anode (7) for grounding.

2. The ultraviolet single-photon detector with a protective structure according to claim 1, characterized in that: The protective ring (4) is made of rubber.

3. The ultraviolet single-photon detector with a protective structure according to claim 2, characterized in that: The first metal gasket (3) is made of aluminum alloy.

4. The ultraviolet single-photon detector with a protective structure according to claim 3, characterized in that: The anode (7) is a resistor anode, or a cross-line anode, or a wedge-shaped anode, or a delay line anode.

5. The ultraviolet single-photon detector with a protective structure according to claim 4, characterized in that: The multi-channel electron multiplier also includes an adapter and N+1 connecting wires; The base plate (1) is provided with N+1 high-voltage interfaces (6), one end of the N+1 connecting wires is connected to the adapter, and the other end is connected to N+1 first metal gaskets (3) through the corresponding high-voltage interfaces (6).

6. An ultraviolet single-photon detector with a protective structure according to any one of claims 1 to 5, characterized in that: The multi-channel electron multiplier also includes four fastening bolts; The pressure ring (5) is provided with four lugs extending outwards on the circumference, and each of the four lugs is provided with a through hole; The bottom plate (1) is provided with threaded holes at the positions of the through holes corresponding to the four lugs; The four fastening bolts respectively pass through the through holes of the corresponding lugs and are threadedly connected with the corresponding threaded holes.

7. An ultraviolet single photon detection system, characterized in that: An ultraviolet single-photon detector with a protective structure and an electronic readout circuit comprising any one of claims 1 to 6; The anode (7) is provided with a connector (11) for leading the signal to an electronic readout circuit.

Images