Centrifugal bending equipment, bending type channel micro-channel plate and preparation method and application of bending type channel micro-channel plate

Abstract

The invention relates to centrifugal bending equipment, a bending type channel micro-channel plate and a preparation method and application of the bending type channel micro-channel plate. The centrifugal bending equipment comprises a high-temperature furnace which is of a cylindrical cavity structure comprising a cavity and a furnace wall and is arranged in the axis vertical direction; a heating body is arranged in the furnace wall; the centrifugal acceleration system comprises a rotating tray; a centrifugal bending fixture is arranged on the rotary tray; the rotary tray and the centrifugal bending fixture can rotate in a horizontal plane around the axis of the high-temperature furnace; the control system is connected with the high-temperature furnace and the centrifugal acceleration system; and the control system sets and controls the temperature in the high-temperature furnace and the rotating speed of the centrifugal bending fixture according to the technological parameters. The technical problem to be solved is how to provide the bending type channel micro-channel plate so as to reduce and eliminate positive ion feedback noise and electron transmission noise of the micro-channel plate. Meanwhile, the preparation process effectively solves the problems of channel aperture deformation and inconsistent bending curvature, and avoids causing non-uniform MCP gain and reduction of imaging resolution.

Description

Technical Field

[0001] The invention belongs to the technical field of microchannel plate manufacturing, and in particular relates to a centrifugal bending device, a curved channel microchannel plate, and a preparation method and application thereof. Background Art

[0002] Microchannel plate (MCP) is a two-dimensional vacuum electron multiplier device. It is the core element for electron multiplication in devices such as low-light image intensifiers, ultraviolet detectors, streak tubes, photomultiplier tubes, and time-of-flight mass spectrometers. It has the advantages of high gain, good temporal and spatial resolution, and small size. The conventional MCP channel is a straight channel structure. However, due to the presence of K in the MCP matrix glass, + 、Na + During the preparation process, the inner wall of the channel may adsorb ions such as H 2 、N 2 , CO 2 , CO, H 2 Gases such as O2 are ionized under the action of the high-density electron cloud formed by secondary electron multiplication. The positive ions generated after ionization move in the opposite direction under the action of the electric field, forming positive ion feedback; positive ion feedback has led to adverse results in the fields of third-generation low-light image intensifiers, photon counting applications, and time-of-flight mass spectrometry. In addition, the straight-channel MCP structure will also form a free electron transmission effect, which can reduce the signal-to-noise ratio of the device in the field of streak tube applications.

[0003] In order to solve the positive ion feedback noise and electron transmission noise problems of straight channel MCP, a lot of research work has been carried out in various application fields. For example, the MCP used in the third-generation image intensifier ensures the working life of the photocathode by preparing an anti-ion feedback film at the input end. However, this method is easy to introduce impurities to contaminate the microchannel during the preparation process, and the ion feedback film is thick, which blocks the electron transmittance of the MCP input surface to a certain extent, reduces the detection efficiency of the low-light image intensifier, and weakens the advantages of the GaAs photocathode of the third-generation image intensifier; in the field of photon technology, the MCP detector adopts a double-chip "V" structure, or a three-chip "Z" structure, and uses a specific angle assembly method to reduce the after pulse caused by ion feedback. However, due to the inevitable misalignment between channels in the Z-type and V-type structures, the problem of a significant decrease in spatial resolution is brought about. In the prior art, various application fields have continuously improved their requirements for resolution, imaging clarity, detection signal limit, service life, etc., but there is no way to solve the positive ion feedback noise and electron transmission noise problems of the straight channel MCP. Summary of the invention

[0004] The main purpose of the present invention is to provide a centrifugal bending device, a curved channel microchannel plate and its preparation method and application. The technical problem to be solved is how to provide a curved channel microchannel plate so that the channel of the microchannel plate has a curvature of the target curvature; positive ions and electrons move in a straight line under the action of an electric field; because the channel has a curvature of the target curvature, the positive ions hit the channel wall when they move in a straight line, and they are captured by the channel surface, thereby reducing and eliminating the positive ion feedback noise; the electrons hit the channel wall when they move in a straight line, so that the electrons cannot be directly transmitted from the channel, thereby reducing and eliminating the electron transmission noise. In addition, in the process of preparing the curved channel structure MCP, the present invention effectively solves the problems of channel aperture deformation and inconsistent curvature, and can avoid problems such as uneven gain of MCP and decreased imaging resolution.

[0005] In order to solve the above problems, the present invention provides a centrifugal bending device, which comprises:

[0006] A high temperature furnace, wherein the high temperature furnace is a cylindrical cavity structure including a chamber and a furnace wall; the high temperature furnace is arranged with the axis as the vertical direction; a heating body is arranged in the furnace wall;

[0007] A centrifugal acceleration system, the centrifugal acceleration system comprising a rotating tray; a centrifugal bending fixture is provided on the rotating tray; the rotating tray and the centrifugal bending fixture can rotate in a horizontal plane around the axis of the high-temperature furnace;

[0008] A control system is electrically connected to the high temperature furnace and the centrifugal acceleration system; the control system controls the temperature in the high temperature furnace and the rotation speed of the centrifugal bending fixture according to process parameter settings.

[0009] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0010] Preferably, in the aforementioned centrifugal bending equipment, the maximum operating temperature of the high-temperature furnace is ≥800°C, the temperature control accuracy is better than ±3°C, and the fastest heating rate is ≥10°C / min.

[0011] Preferably, in the aforementioned centrifugal bending equipment, the rotating tray is an integrated barrel structure made of high temperature resistant stainless steel material.

[0012] Preferably, in the aforementioned centrifugal bending device, a plurality of hollow structures are symmetrically arranged on the bottom surface of the rotating tray.

[0013] Preferably, in the aforementioned centrifugal bending equipment, the centrifugal acceleration system includes a centrifugal mechanism main shaft; the centrifugal mechanism main shaft drives the rotating tray to rotate; the centrifugal mechanism main shaft is made of high-temperature alloy steel; and a rubber O-ring is provided at the portion where the centrifugal mechanism main shaft is combined with the high-temperature furnace.

[0014] Preferably, in the aforementioned centrifugal bending equipment, the maximum speed of the centrifugal acceleration system is greater than 4000r / min, the speed control accuracy is better than ±60r / min, and the spindle runout is less than 0.2mm.

[0015] Preferably, in the aforementioned centrifugal bending equipment, the centrifugal bending fixture is made of high temperature resistant stainless steel.

[0016] Preferably, the aforementioned centrifugal bending equipment, wherein a groove is provided on the diameter of the rotating tray; the centrifugal bending fixture comprises a rod; the rod is inserted into the groove; the centrifugal bending equipment also comprises a clamping device; the clamping device cooperates with the groove to fix the centrifugal bending fixture on the rotating tray.

[0017] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing a curved channel microchannel plate proposed by the present invention, the method comprises the following steps:

[0018] 1) placing a straight channel type microchannel blank in a centrifugal bending fixture; the centrifugal bending fixture includes a curved surface with the same curvature as the target curvature of the curved channel; when placing the blank, the axis of the straight channel type microchannel is controlled to be in a vertical direction, and the curved surface is controlled to face a direction away from the rotation center;

[0019] 2) heating and centrifugally rotating according to the process system so that one side of the blank is in contact with the curved surface;

[0020] 3) Cooling and centrifugal rotation according to the process system; optical processing to obtain a curved channel microchannel plate.

[0021] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0022] Preferably, in the above-mentioned preparation method, the process system of step 2) is as follows: heating at a heating rate of 1 to 2°C / min; heating to T 0 The method comprises the following steps: starting centrifugal rotation at a first speed; heating to a target temperature T, keeping the temperature, and continuing centrifugal rotation at the first speed for 2 to 3 hours; adjusting the speed of the centrifugal rotation to adjust it to a second speed within 15 to 40 minutes; and then centrifugally rotating at the second speed for 1.5 to 5 hours; the first speed is 500 to 600 r / min; the second speed is 4000 to 4500 r / min; the blank plate includes a skin glass and a core glass; the T 0 Lower than the glass transition temperature of the leather glass; T 1 <T<T 2 , T is the target temperature, T 1is the glass transition temperature of the leather glass, T 2 is the glass transition temperature of the core glass;

[0023] Step 3) The process system is as follows: cooling at a cooling rate of 0.5 to 1.0 °C / min, adjusting the speed of the centrifugal rotation during the cooling process to adjust it to the third speed within 15 to 30 minutes, and then centrifugally rotating at the third speed; cooling to T 3 Then stop the centrifugal rotation; cool naturally; the third speed is 1000-1500r / min; the T 3 Lower than the glass transition temperature of the leather glass; all the above temperature units are ° C.

[0024] Preferably, in the aforementioned preparation method, the straight channel type microchannel blank has an outer shape of a rectangular parallelepiped, wherein the dimension along the axial direction of the straight channel type microchannel is the longest, which is 1.5 to 2.0 times the dimensions of the other two dimensions.

[0025] Preferably, in the aforementioned preparation method, the target temperature T is higher than the glass transition temperature T of the core glass. 2 5-10℃ lower.

[0026] Preferably, in the aforementioned preparation method, the optical processing is to perform slicing, contour carving, optical grinding and / or optical polishing after the workpiece is cooled to below 50°C.

[0027] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions: According to a curved channel microchannel plate proposed by the present invention, the channel in the microchannel plate has a preset target curvature.

[0028] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0029] Preferably, the aforementioned curved channel microchannel plate is prepared according to the aforementioned preparation method.

[0030] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions: According to the present invention, a microchannel plate with curved channels as mentioned above is used in a low-light image intensifier, an ultraviolet detector, a streak tube or a time-of-flight mass spectrometer.

[0031] By means of the above technical solution, the centrifugal bending device, curved channel microchannel plate and its preparation method and application proposed by the present invention have at least the following advantages:

[0032] The centrifugal bending device, curved channel microchannel plate and preparation method and application thereof proposed by the present invention are as follows: a centrifugal bending fixture including a curved surface matching the target curvature of the curved channel is designed, and the curved surface is installed on a rotating disk of the centrifugal bending device with the curved surface facing away from the rotation center; a straight channel type microchannel blank plate is symmetrically placed in the centrifugal bending fixture; then, heating and centrifugal rotation are performed according to a process system, so that the side of the straight channel type microchannel blank plate in contact with the curved surface of the centrifugal bending fixture is tightly fitted to the curved surface, so that the blank plate is bent as a whole, thereby also making the straight channel-type channels in the straight channel type microchannel blank plate bend at the same angle; then, cooling and centrifugal rotation are performed according to a process system, and during the cooling process, a certain centrifugal force is continuously applied to the MCP blank plate so that the shape and angle of the curved channel that has been formed are stably maintained, thereby avoiding changes in the curvature of the MCP channel that has been bent and formed, thereby obtaining the curved channel microchannel plate of the present invention. The technical solution of the present invention not only obtains a curved channel microchannel plate, but also the structural design of the curved channel makes it easy for positive ions under the action of an electric field to collide with the channel wall when moving in a straight line and be quickly captured by the channel surface, thereby reducing and eliminating positive ion feedback noise; and electrons under the action of an electric field collide with the channel wall when moving in a straight line, so that the electrons cannot be directly transmitted from the channel, thereby reducing and eliminating electron transmission noise; and when the curved channel microchannel plate is prepared by the technical solution of the present invention, the problems of channel aperture deformation, inconsistent bending curvature, etc. can be effectively solved, thereby avoiding the problems of uneven MCP gain and reduced imaging resolution.

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of a centrifugal bending device in an embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the state in which a straight channel type microchannel blank is placed in a centrifugal bending fixture in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description of a centrifugal bending device, a curved channel microchannel plate and its preparation method and application proposed in accordance with the present invention, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments.

[0037] A specific embodiment of the present invention provides a centrifugal bending device, which includes a high-temperature furnace, a centrifugal acceleration system, an electrical control system and a computer monitoring system. The specific description is as follows:

[0038] As attached Figure 1 The figure shows a top view of the centrifugal bending equipment of the present invention after being cut along a certain horizontal plane. The centrifugal bending equipment comprises: a high-temperature furnace 1, which is a cylindrical cavity structure including a chamber and a furnace wall, and its interior is a cylindrical structure to ensure that the centrifugal acceleration system is at a uniform distance from the furnace wall of the high-temperature furnace; during the operation of the high-temperature furnace, it is installed with the axis as the vertical direction. The technical purpose of such an arrangement is to enable the centrifugal acceleration system to rotate in a horizontal plane when rotating around its axis, so that the centrifugal acceleration system rotates smoothly, and the force at each position on the circumference at an equal distance from the axis is uniform, which is conducive to ensuring the stable and consistent quality of the prepared products; a heating body 11 is arranged in the furnace wall to achieve high-temperature heating of the objects in the chamber, while ensuring the temperature uniformity and stability at each position in the chamber.

[0039] In a specific embodiment of the present invention, in order to ensure uniform temperature in the effective area and to match the conventional processing size of the microchannel plate, the present invention preferably has a diameter of 1000 mm and a height of 500 mm for the uniform temperature effective area in the high temperature furnace.

[0040] In a specific embodiment of the present invention, the configuration of each component in the high temperature furnace can adopt any form of high temperature resistant configuration in the art. In particular, in order to ensure that the glass varieties that can be processed by the microchannel plate have a wide range of adaptability, the configuration of each component in the high temperature furnace is preferably such that the maximum operating temperature of the high temperature furnace is ≥800°C; in order to ensure the stability and accurate control of the temperature in the furnace, the configuration of each component in the high temperature furnace is preferably such that the temperature control accuracy is better than ±3°C; in order to ensure the process time and efficiency and meet the requirements of product quality, the configuration of each component in the high temperature furnace is preferably such that the fastest heating rate is ≥10°C / min.

[0041] In a specific embodiment of the present invention, the centrifugal bending equipment also includes a centrifugal acceleration system, which includes a power system, a rotating tray 21 and a centrifugal bending fixture 22; the centrifugal bending fixture is arranged on the rotating tray; the rotating tray and the centrifugal bending fixture can rotate in a horizontal plane around the axis of the high-temperature furnace.

[0042] In a specific embodiment of the present invention, the power system is implemented by a three-phase motor, a speed increaser and a motor inverter. As long as the requirement of continuous speed change can be met, the specific implementation form is not specifically limited in the present invention.

[0043] In a specific embodiment of the present invention, the rotating tray is a deep cylindrical structure, and the purpose of such a configuration is to provide a stable boundary for the centrifugal acceleration fixture to prevent it from being thrown out due to high-speed rotation.

[0044] In a specific embodiment of the present invention, the rotating tray is preferably made of high temperature resistant stainless steel through one-piece machining, the purpose of which is to ensure dynamic balance in a rotating state.

[0045] In a specific embodiment of the present invention, it is preferred that a plurality of hollow structures 211 are symmetrically arranged on the bottom surface of the rotating tray, as shown in the attached figure. Figure 1 The four circular holes shown are designed in such a way as to reduce the weight of the rotating tray, so that the lightweight tray is conducive to the rotation of the centrifugal acceleration system.

[0046] In a specific embodiment of the present invention, a plurality of grooves 212 are provided on the diameter of the rotating tray, and the angle difference between two adjacent grooves is equal, so that the grooves are evenly distributed on the rotating tray, so as to maintain a better dynamic balance when the rotating tray rotates; the centrifugal bending fixture includes a rod; the rod is inserted into the groove; the centrifugal bending equipment also includes a clamping device, the purpose of such design is to prevent the centrifugal bending fixture from flying out under high-speed rotation; the clamping device cooperates with the groove to fix the centrifugal bending fixture on the rotating tray.

[0047] In a specific embodiment of the present invention, the centrifugal acceleration system includes a centrifugal mechanism main shaft 23; the centrifugal mechanism main shaft drives the rotating tray to rotate; in order to adapt to the operating temperature in the high-temperature furnace, the material of the centrifugal mechanism main shaft is preferably high-temperature alloy steel; the part where the centrifugal mechanism main shaft is combined with the high-temperature furnace is provided with a rubber O-ring for sealing to avoid the rotating joint causing temperature disturbance in the furnace.

[0048] In a specific embodiment of the present invention, the configuration of each component of the centrifugal acceleration system can adopt any configuration in the art. In order for the centrifugal acceleration system to better achieve the processing quality requirements and process parameter setting requirements of the curved channel microchannel plate, the present invention preferably configures each component to meet the following conditions: the maximum speed is greater than 4000r / min, the speed control accuracy is better than ±60r / min, and the spindle runout is less than 0.2mm.

[0049] In a specific embodiment of the present invention, the centrifugal bending fixture is a high temperature resistant mold with a specific curvature, and the curvature design is obtained by processing according to the channel bending angle of the MCP to be bent. In order to ensure the curvature accuracy of the channel in the prepared curved channel microchannel plate, the present invention preferably uses high temperature resistant stainless steel, and further preferably uses Invar. The reason for such design is that high temperature resistant stainless steel, especially Invar, has good high temperature resistance and high dimensional accuracy under high temperature conditions, thereby ensuring the constant radius of curvature of the centrifugal bending fixture under high temperature conditions.

[0050] In a specific embodiment of the present invention, the centrifugal bending equipment also includes a control system, including an electrical control system and a computer monitoring system; the control system is connected to the high-temperature furnace and the centrifugal acceleration system via a data cable; the control system controls the temperature in the high-temperature furnace and the rotation speed of the centrifugal bending fixture according to process parameter settings, and is mainly used for temperature control, temperature rise curve control, temperature drop curve control, speed control and speed increase and decrease time control.

[0051] The centrifugal bending device proposed in the present invention makes it possible to prepare a curved channel microchannel plate, which can accurately control the curvature of the curved channel through the specific curved surface of the centrifugal bending fixture.

[0052] The present invention also provides a method for preparing a curved channel microchannel plate, which comprises the following steps: 1) placing a straight channel microchannel blank plate 3 in a centrifugal bending fixture 22; the centrifugal bending fixture comprises a curved surface 221 having the same curvature as the target curvature of the curved channel, as shown in the attached Figure 2 As shown; when placing the blank, the axis of the straight channel type microchannel is controlled to be in the vertical direction, and the curved surface is controlled to be directed away from the rotation center; in order to ensure that the centrifugal bending fixture can maintain a good dynamic balance when rotating, it is preferred that the centrifugal bending fixture is stacked and arranged, and the straight channel type microchannel blank is placed symmetrically; 2) heating and centrifugal rotation are performed according to the process system to make one side of the blank fit the curved surface; the process system in this technical solution is not specifically limited, according to the properties of the glass material of the straight channel type microchannel blank, as long as it can be guaranteed to soften at the process temperature and can be closely fitted to the curved surface under the centrifugal force of centrifugal rotation; 3) cooling and centrifugal rotation are performed according to the process system; the process system in this technical solution is not specifically limited, according to the properties of the glass material of the straight channel type microchannel blank, as long as it can be guaranteed that the channel curvature formed in step 2) can be stably maintained during the cooling process; finally, optical processing is performed to obtain a curved channel microchannel plate.

[0053] In a specific embodiment of the present invention, the process system preferably includes the following steps: starting slow centrifugal rotation when the temperature is raised to a certain temperature; keeping the temperature after the temperature is raised to the target temperature, while continuing slow centrifugal rotation; after the temperature of the MCP blank is uniform, gradually increasing the centrifugal rate, so that the MCP blank undergoes fiber bending deformation under the dual effects of high temperature and centrifugal force, and gradually fits the curved surface of the centrifugal bending fixture completely, thereby realizing the bending forming of the MCP with a specific curvature; after the MCP is bent and formed, entering the slow cooling stage, while gradually reducing the centrifugal rotation speed, the purpose is to continue to apply a certain centrifugal force to the MCP blank to avoid changes in the curvature of the bent MCP; when the temperature in the high-temperature furnace is reduced to a certain temperature, the rapid cooling stage can be carried out, and the entire centrifugal bending process is completed. When the temperature in the high-temperature furnace is reduced to below 50°C, the bent MCP is taken out and optically processed, and after the workpiece is cooled to below 50°C, slicing, carving, optical grinding and / or optical polishing are performed, and finally an MCP with a curved channel structure is prepared.

[0054] In a specific embodiment of the present invention, in order to prevent the MCP blank from bursting due to excessive thermal stress during heating and centrifugal rotation, the preferred heating rate of the present invention is 1° C. to 2° C. / min.

[0055] Since the MCP blank is a composite material composed of two materials, the skin glass and the core glass. Generally, the glass transition temperature of the skin glass is lower than the glass transition temperature of the core material. When the temperature is much lower than the glass transition temperature of the skin glass, centrifugal rotation will not play any role, so premature centrifugation will lead to energy consumption and waste. In a specific embodiment of the present invention, it is preferred to heat the glass to a temperature T slightly lower than the glass transition temperature of the skin glass. 0 Then start centrifugal rotation at a speed of 500-600 r / min.

[0056] The centrifugal bending temperature is a key parameter for achieving MCP channel bending. When the centrifugal bending temperature is too low, the viscosity of the glass material is too high, and uniform bending of a specific curvature cannot be achieved. In addition, the MCP will produce greater structural stress, affecting the strength and reliability of the MCP. When the centrifugal bending temperature is too high, the MCP channel will be deformed and cannot meet the use requirements. The centrifugal bending temperature of MCP blanks made of different materials is also different.

[0057] In order to maintain the roundness of the channel during centrifugal bending, the centrifugal bending temperature, that is, the target temperature T, is preferably between the glass transition temperature T of the leather glass. 1 and the core glass glass transition temperature T 2 Between, that is, T 1 <T<T 2It is further preferred that the target temperature T is lower than the glass transition temperature T of the core glass. 2 Preferably, the MCP blank is heated to the target temperature T, kept warm, and centrifugally rotated at a speed of 500 to 600 r / min for 2 to 3 hours to make the internal and external temperatures of the MCP blank uniform.

[0058] After the internal and external temperatures of the MCP blank are uniform, high-speed centrifugal rotation begins. In order to make the centrifugal rotation speed transition smoothly, the present invention adjusts the centrifugal rotation speed so that the rotation speed increases from 500-600r / min to 4000-4500r / min within 15-40min; then, the centrifugal rotation is performed at a speed of 4000-4500r / min for 1.5-5h at the target temperature T, so that the MCP blank undergoes fiber bending deformation under the dual effects of high temperature and centrifugal force, and gradually fits completely with the curved surface of the centrifugal bending fixture, thereby realizing the bending forming of the MCP with a specific curvature.

[0059] After the bending forming of the specific curvature of the MCP is completed, in order to accurately maintain the specific curvature of the channel during the cooling process, the present invention preferably continues to maintain centrifugal rotation during the cooling process, preferably cooling at a cooling rate of 0.5 to 1.0°C / min, and adjusting the speed of the centrifugal rotation during the cooling process so that the rotation speed is reduced from 4000 to 4500 r / min to 1000 to 1500 r / min within 15 to 30 minutes, and then centrifugally rotates while cooling until the temperature drops to T 3 Then stop the centrifugal rotation, T 3 The temperature is lower than the glass transition temperature of the leather glass; at this time, the top curvature of the channel is basically finalized, and continuing slow cooling and centrifugal rotation will no longer have a better effect. The centrifugal rotation can be stopped, and the heating can be turned off at the same time, and natural cooling is performed, thus completing the entire centrifugal bending process.

[0060] The MCP blank is processed according to conventional processes, generally the MCP blank obtained by drawing single wires, arranging rods, drawing multifilaments, arranging plates, and melt-pressing is cut and processed, and the conventional MCP blank is generally in the shape of a regular hexagonal prism. In order to facilitate the bending and forming of the channel, the present invention preferably cuts the MCP blank into a rectangular parallelepiped shape, wherein the length and width of the rectangular parallelepiped (the length and width are both perpendicular to the channel axis) are determined according to the MCP specifications to be prepared, and the height of the rectangular parallelepiped (in the direction parallel to the channel axis) is generally 1.5 to 2.0 times the length and width, that is, the MCP blank is the longest along the axial direction of the straight channel type microchannel, which is 1.5 to 2.0 times the other two dimensions.

[0061] In a specific embodiment of the present invention, for an MCP with a specification of Φ25 mm, preferably, its length×width size is ≥30 mm×30 mm, and its height is ≥45 mm to 60 mm. The MCP channel direction should be consistent with the height direction of the cuboid.

[0062] The present invention further provides a curved channel microchannel plate, in which the channels have a preset target curvature, which can be prepared by the aforementioned preparation method, but is not limited to the aforementioned preparation method.

[0063] The present invention also proposes an application of the aforementioned curved channel microchannel plate in a low-light image intensifier, an ultraviolet detector, a streak tube or a time-of-flight mass spectrometer.

[0064] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0065] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0066] Examples 1 to 5

[0067] The glass transition temperature of the skin glass of the straight channel MCP blank used in this embodiment is 515°C, and the softening temperature is 595°C; the glass transition temperature of the core glass is 665°C, and the softening temperature is 715°C.

[0068] The MCP blank is cut into a rectangular blank; the cut blank is loaded into the centrifugal bending fixture of the centrifugal bending equipment, and the centrifugal bending fixture includes a curved surface with a target specific curvature; when placing the blank, the axis of the channel is required to be in the vertical direction, and the curved surface is facing away from the rotation center; the centrifugal bending fixture with the MCP blank to be bent is firmly fixed on the rotating tray to prevent the fixture from flying off during high-speed centrifugal rotation.

[0069] Set the heating rate and the temperature T at which centrifugal rotation starts 0, first speed, target temperature T, first speed stirring time at target temperature, second speed, first to second speed adjustment time, first speed stirring time at target temperature, cooling speed, third speed, second to third speed adjustment time, temperature when centrifugal rotation is stopped, etc., the centrifugal bending equipment is automatically controlled by the control system to bend the MCP blank; after stopping the centrifugal rotation, the heating is turned off, and the temperature is naturally lowered to below 50°C for optical processing to obtain a curved channel microchannel plate; the bending angle of the channel is detected. The process parameters and test results are shown in Table 1.

[0070] Table 1

[0071]

[0072] The positive ion feedback noise, electron transmission noise and bending angle of the curved channel microchannel plate prepared in the above embodiments were tested, and a straight channel MCP blank without bending processing was used as a control group. The results showed that the positive ion feedback noise of the curved channel microchannel plate prepared in the embodiments was reduced by more than 50% compared with the control group, the electron transmittance was reduced by one order of magnitude, and the channel aperture bending curvature was consistent.

[0073] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0074] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A centrifugal bending device, characterized in that: It includes: A high-temperature furnace, which is a cylindrical cavity structure including a chamber and a furnace wall; the high-temperature furnace is arranged with its axis in the vertical direction; A heating element is arranged inside the furnace wall; A centrifugal acceleration system, which includes a rotating tray; a centrifugal bending fixture is arranged on the rotating tray; the rotating tray and the centrifugal bending fixture can rotate around the axis of the high-temperature furnace in the horizontal plane; A control system, which is connected to the high-temperature furnace and the centrifugal acceleration system; the control system controls the temperature inside the high-temperature furnace and the rotation speed of the centrifugal bending fixture according to the set process parameters.

2. The centrifugal bending device according to claim 1, characterized in that: The maximum operating temperature of the high-temperature furnace is ≥800 °C, the temperature control accuracy is better than ±3 °C, and the fastest heating rate is ≥10 °C / min.

3. The centrifugal bending device according to claim 1, characterized in that: The rotating tray is an integral cylindrical structure made of high-temperature resistant stainless steel.

4. The centrifugal bending device according to claim 3, characterized in that: A number of hollow structures are symmetrically arranged on the bottom surface of the rotating tray.

5. The centrifugal bending device according to claim 1, characterized in that: The centrifugal acceleration system includes a main shaft of the centrifugal mechanism; the main shaft of the centrifugal mechanism drives the rotating tray to rotate; the material of the main shaft of the centrifugal mechanism is high-temperature alloy steel; a rubber O-ring seal is arranged at the joint of the main shaft of the centrifugal mechanism and the high-temperature furnace.

6. The centrifugal bending device according to claim 1, characterized in that: The maximum rotation speed of the centrifugal acceleration system is greater than 4000 r / min, the rotation speed control accuracy is better than ±60 r / min, and the spindle runout is less than 0.2 mm.

7. The centrifugal bending device according to claim 1, characterized in that: The material of the centrifugal bending fixture is high-temperature resistant stainless steel.

8. The centrifugal bending device according to claim 1, characterized in that: A groove is arranged on the diameter of the rotating tray; the centrifugal bending fixture includes a rod; the rod is clamped into the groove; the centrifugal bending device further includes a pressing device; the pressing device cooperates with the groove to fix the centrifugal bending fixture on the rotating tray.

9. A method for preparing a curved channel microchannel plate, characterized in that: It includes the following steps: 1) Place the straight-channel microchannel blank in the centrifugal bending fixture; the centrifugal bending fixture includes a curved surface with the same curvature as the target curvature of the bent-channel; when placing the blank, control the axis of the straight-channel microchannel to be in the vertical direction, and control the curved surface to face away from the rotation center; 2) Heat up and perform centrifugal rotation according to the process regime to make one side of the blank fit the curved surface; 3) Cool down and perform centrifugal rotation according to the process regime; perform optical processing to obtain a bent-channel microchannel plate.

10. The preparation method according to claim 9, characterized in that: The process regime in step 2) is as follows: heat up at a heating rate of 1-2 °C / min; start centrifugal rotation at the first speed when heating up to T0; continue centrifugal rotation at the first speed for 2-3 h when heating up to the target temperature T and keeping warm; adjust the centrifugal rotation speed so that it is adjusted to the second speed within 15-40 min; then perform centrifugal rotation at the second speed for 1.5-5 h; the first speed is 500-600 r / min; the second speed is 4000-4500 r / min; the blank includes skin glass and core glass; T0 is lower than the glass transition temperature of the skin glass; T1 < T < T2, where T is the target temperature, T1 is the glass transition temperature of the skin glass, and T2 is the glass transition temperature of the core glass; Step 3) The process system is as follows: cooling at a cooling rate of 0.5 to 1.0°C / min, adjusting the speed of centrifugal rotation during the cooling process to adjust it to the third speed within 15 to 30 minutes, and then centrifugally rotating at the third speed; stopping the centrifugal rotation after cooling to T3; cooling naturally; the third speed is 1000 to 1500r / min; the T3 is lower than the glass transition temperature of the leather glass; all the above temperature units are ℃.

11. The preparation method according to claim 9, characterized in that: The straight channel type microchannel blank has an outer shape of a rectangular parallelepiped, wherein the dimension along the axial direction of the straight channel type microchannel is the longest, which is 1.5 to 2.0 times the dimensions of the other two dimensions.

12. The preparation method according to claim 9, characterized in that: The target temperature T is 5 to 10° C. lower than the glass transition temperature T2 of the core glass.

13. The preparation method according to claim 9, characterized in that: The optical processing is to perform slicing, contour carving, optical grinding and / or optical polishing after the workpiece is cooled to below 50°C.

14. A curved channel microchannel plate, characterized in that: The channel in the microchannel plate has a preset target curvature.

15. The curved channel microchannel plate according to claim 14, characterized in that: It is prepared according to the preparation method according to any one of claims 9 to 13.

16. Use of the curved channel microchannel plate according to claim 14 or 15 in a low-light image intensifier, an ultraviolet detector, a streak tube or a time-of-flight mass spectrometer.

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