CN118068391B - Ion beam divergence angle measuring device and ion beam divergence angle measuring method - Google Patents

Abstract

The invention provides an ion beam divergence angle measuring device, which comprises: an ion source for generating a beam of ions. The aperture baffle comprises a plurality of apertures for limiting the path of the ion beam, and the position of the ion beam passing through the apertures is a first position. And the microchannel plate is used for amplifying ions in the ion beam current to generate an electron cloud signal. The location where the ion beam hits the microchannel plate is the second location. The anode plate comprises a plurality of anode strips which are distributed at equal intervals and is used for collecting electronic cloud signals and converting the electronic cloud signals into electric signals. And a processing module that generates ion beam divergence angle information based on the first distance and the second distance of the ion beam current in the electrical signal. The first distance is obtained based on the distance between the micro-channel plate and the small hole baffle plate, and the second distance is obtained based on the distance between the horizontal projection position of the first position on the micro-channel plate and the second position. The invention also provides a measuring method of the ion beam divergence angle.

Description

Ion beam divergence angle measuring device and ion beam divergence angle measuring method

Technical Field

The present invention relates to the technical field of ion beam divergence angle measurement, and more specifically to an ion beam divergence angle measurement device and an ion beam divergence angle measurement method.

Background technique

The precise measurement of the ion beam divergence angle is crucial to evaluating the resolution and sensitivity of the ground-based calibration system. The ion beam divergence angle reflects the spatial distribution and directionality of the ion beam. By accurately measuring the ion beam divergence angle, the measurement range and accuracy of the ground-based calibration system for the ion beam can be determined, and the performance of the space plasma detection instrument can be evaluated.

The related technology uses traditional optical imaging methods to image the spot of the ion beam on a fluorescent screen or a photodetector based on an optical system, and then estimates the angle of the divergence angle of the ion beam by analyzing the shape and size of the spot.

In the process of realizing the concept of the present invention, the inventors found that there are at least the following problems in the related technology: the related technology relies on external equipment to detect and analyze the physical properties of the ion beam, and it is difficult to further process the collected data and to extract information on the ion beam divergence angle therefrom, resulting in low measurement accuracy of the ion beam divergence angle.

Summary of the invention

In view of the above problems, the present invention provides an ion beam divergence angle measuring device and an ion beam divergence angle measuring method.

According to a first aspect of the present invention, an ion beam divergence angle measuring device is provided, comprising: an ion source for generating an ion beam. A pinhole baffle, comprising a plurality of pinholes for limiting the path of the ion beam, wherein the position where the ion beam passes through the pinholes is the first position. A microchannel plate, for amplifying ions in the ion beam to generate an electron cloud signal. The position where the ion beam hits the microchannel plate is the second position. An anode plate, comprising a plurality of anode strips distributed at equal intervals, for collecting the electron cloud signal and converting the electron cloud signal into an electrical signal. And a processing module, for generating ion beam divergence angle information based on the first distance and the second distance of the ion beam in the electrical signal. The first distance is obtained based on the spacing between the microchannel plate and the pinhole baffle, and the second distance is obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position.

According to an embodiment of the present invention, the spacing between the plurality of anode strips of the anode plate is 100-500 μm.

According to an embodiment of the present invention, the small hole baffle comprises four small holes, the four small holes are equally spaced and symmetrically distributed on the small hole baffle, the shape of the small holes comprises a circle, and the diameter of the small holes is 0.1-10 mm.

According to an embodiment of the present invention, the microchannel plate comprises a first microchannel plate and a second microchannel plate, and the first microchannel plate and the second microchannel plate are stacked.

According to an embodiment of the present invention, the processing module includes a discrimination submodule, and the discrimination submodule is used to distinguish between a noise event and an event in which an electron cloud signal formed by the ion beam passing through the microchannel plate hits the anode plate.

According to an embodiment of the present invention, the processing module further includes a signal amplifying circuit and a filtering circuit, wherein the signal amplifying circuit is used to amplify the electrical signal, and the filtering circuit is used to shape and filter the amplified electrical signal.

According to an embodiment of the present invention, the processing module further comprises a power module, and the power module is used to generate power required by the microchannel plate and power required by the processing module.

According to an embodiment of the present invention, the ion beam divergence angle measurement device further includes an interaction module, and the interaction module is used to display the ion beam divergence angle information generated by the processing module.

According to an embodiment of the present invention, the energy of the ion beam generated by the ion source is 250-5000 eV.

The second aspect of the present invention provides a method for measuring the divergence angle of an ion beam, comprising: obtaining an ion beam through an ion source. Obtaining a first position where the ion beam passes through a pinhole through a pinhole baffle. Amplifying ions in the ion beam through a microchannel plate to generate an electron cloud signal, and obtaining a second position based on the position where the ion beam hits the microchannel plate. Collecting the electron cloud signal through an anode plate and converting the electron cloud signal into an electrical signal. And generating ion beam divergence angle information based on the first distance and the second distance of the ion beam in the electrical signal through a processing module. The first distance is obtained based on the spacing between the microchannel plate and the pinhole baffle, and the second distance is obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position.

According to the embodiments of the present invention, the present invention directly measures the interaction between the ion beam and the microchannel plate, reduces the measurement error of the ion beam divergence angle caused by the external device resolution and data processing, and realizes the rapid measurement of the ion beam divergence angle. In addition, the present invention is based on the pinhole baffle to limit the propagation path of the ion beam, the microchannel plate amplifies the secondary electrons generated by the ion impact to form an electron cloud signal, the anode plate can convert the electron cloud signal into an electrical signal, and based on a plurality of anode strips distributed at equal intervals, the measurement accuracy of the ion beam divergence angle is improved. In addition, the processing module can receive the electrical signal and generate the ion beam divergence angle information, which reduces the complexity of human intervention and data processing and improves the measurement accuracy of the ion beam divergence angle.

BRIEF DESCRIPTION OF THE DRAWINGS

The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG1 is a schematic structural diagram of an ion beam divergence angle measuring device according to an embodiment of the present invention;

FIG2 is a schematic diagram showing the position distribution of small holes on a small hole baffle according to an embodiment of the present invention;

FIG3 is a schematic diagram showing a flight trajectory of an ion beam according to an embodiment of the present invention;

FIG4 is a schematic diagram showing the structure of an anode strip according to an embodiment of the present invention;

FIG5 shows a schematic structural diagram of a processing module according to an embodiment of the present invention; and

FIG. 6 shows a flow chart of a method for measuring an ion beam divergence angle according to an embodiment of the present invention.

Detailed ways

Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and/or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

The ground calibration system of space plasma detection instruments mainly tests and calibrates space plasma detection instruments by using an ion source to generate an ion beam with similar plasma parameters to those in the space environment. The ground calibration system can be used to calibrate the sensitivity, response characteristics and energy resolution of space plasma detection instruments to ensure the normal operation and accurate measurement of space plasma detection instruments in space. By accurately measuring known plasmas on the ground, the measurement errors of space plasma detection instruments can be evaluated, and data correction can be performed to improve the accuracy and credibility of the data.

In the ground calibration system, the quality of the ion beam is a key factor affecting the calibration accuracy. If the parameter information of the ion beam cannot be accurately measured, the ground calibration system cannot be effectively calibrated, which may lead to large errors in the final measurement results. By comparing the ion beam information measured by the ground calibration system with the known ion beam information, the sensitivity, resolution and accuracy of the ground calibration system can be evaluated, providing an important basis for further optimizing the performance of space plasma detection instruments.

The accurate measurement of ion beam divergence angle is crucial to evaluate the resolution and sensitivity of the ground calibration system. The ion beam divergence angle reflects the spatial distribution and directionality of the ion beam. By accurately measuring the ion beam divergence angle, it is helpful to determine the measurement range and accuracy of the ground calibration system for the ion beam, and then evaluate the performance of the space plasma detection instrument.

The related technology uses traditional optical imaging methods to image the spot of the ion beam on a fluorescent screen or a photodetector based on an optical system, and then estimates the divergence angle of the ion beam by analyzing the shape and size of the spot.

In the process of realizing the concept of the present invention, the inventors found that there are at least the following problems in the related technology: the related technology relies on external equipment to detect and analyze the physical properties of the ion beam, and it is difficult to further process the collected data and to extract information on the ion beam divergence angle therefrom, resulting in low measurement accuracy of the ion beam divergence angle.

In view of this, an embodiment of the present invention provides an ion beam divergence angle measurement device.

FIG. 1 shows a schematic structural diagram of an ion beam divergence angle measuring device according to an embodiment of the present invention.

As shown in FIG1 , the ion beam divergence angle measuring device includes an ion source 110, a pinhole baffle 120, a microchannel plate 130, an anode plate 140 and a processing module 150. The ion source 110 is used to generate an ion beam. The pinhole baffle 120 includes a plurality of pinholes for limiting the path of the ion beam, and the position where the ion beam passes through the pinhole is the first position. The microchannel plate 130 is used to amplify the ions in the ion beam to generate an electron cloud signal. The position where the ion beam hits the microchannel plate 130 is the second position. The anode plate 140 includes a plurality of anode strips distributed at equal intervals for collecting the electron cloud signal and converting the electron cloud signal into an electrical signal. And the processing module 150 generates ion beam divergence angle information based on the first distance and the second distance of the ion beam in the electron cloud electrical signal. Among them, the first distance is obtained based on the spacing between the microchannel plate 130 and the pinhole baffle 120, and the second distance is obtained based on the spacing between the position of the horizontal projection of the first position on the microchannel plate 130 and the second position.

According to an embodiment of the present invention, the ion beam divergence angle measuring device may further include an ion accelerator and a focusing module. The ion source 110 may convert atoms or molecules into charged ions and generate an ion beam. The generated ion beam may pass through an ion accelerator, which may accelerate the ions in the ion beam through an electric field or a magnetic field, and accelerate the ions to a desired energy range. After the ions in the ion beam are accelerated, it is necessary to focus the ions using a focusing module to focus the ions within a desired spatial range and reduce the diameter of the ion beam to a desired size, thereby ensuring that the ion beam has a uniform and symmetrical shape and highly consistent directionality.

According to an embodiment of the present invention, the ion beam passes through the small hole on the small hole baffle 120, and the position where the ion beam passes through the small hole is marked as the first position. The small hole on the small hole baffle 120 can limit the propagation path of the ion beam.

According to an embodiment of the present invention, the ion beam passing through the small hole on the small hole baffle 120 will hit the microchannel plate 130, and the position where the ion beam hits the microchannel plate 130 is the second position. The first distance can be obtained based on the spacing between the microchannel plate 130 and the small hole baffle 120, and the second distance can be obtained based on the spacing between the position of the horizontal projection of the first position on the microchannel plate 130 and the second position. The microchannel plate 130 will amplify the secondary electrons generated by the ion impact and generate an electron cloud signal.

According to an embodiment of the present invention, the anode plate 140 can collect electron cloud signals and convert the electron cloud signals into electrical signals. The anode plate 140 includes a plurality of anode strips, and the position where the ion beam passes through the small hole and the position where the ion beam hits the microchannel plate 130 can be accurately distinguished based on the plurality of anode strips evenly spaced on the anode plate 140, that is, the first position and the second position can be distinguished.

According to an embodiment of the present invention, the processing module 150 may be used to receive an electrical signal, and generate ion beam divergence angle information based on a first distance and a second distance of the ion beam in the electrical signal.

According to the embodiments of the present invention, the present invention directly measures the interaction between the ion beam and the microchannel plate, reduces the measurement error of the ion beam divergence angle caused by the external device resolution and data processing, and realizes the rapid measurement of the ion beam divergence angle. In addition, the present invention is based on the pinhole baffle to limit the propagation path of the ion beam, the microchannel plate amplifies the secondary electrons generated by the ion impact to form an electron cloud signal, the anode plate can convert the electron cloud signal into an electrical signal, and based on a plurality of anode strips distributed at equal intervals, the measurement accuracy of the ion beam divergence angle is improved. In addition, the processing module can receive the electrical signal and generate the ion beam divergence angle information, which reduces the complexity of human intervention and data processing and improves the measurement accuracy of the ion beam divergence angle.

According to an embodiment of the present invention, the energy of the ion beam generated by the ion source is 250-5000 eV.

According to an embodiment of the present invention, the ion source can be a low-energy ion source for emitting a low-energy ion beam with a predetermined energy. The low-energy ion source has the characteristics of high ion current density and high controllability, and can accurately control the energy and flow intensity of the ion beam. The predetermined energy of the ion beam can be 250-5000eV.

According to an embodiment of the present invention, the energy of the ion beam is 250-5000 eV, and the ion source can provide precise energy control, which is conducive to accurately measuring the divergence angle of the ion beam.

According to an embodiment of the present invention, the small hole baffle includes four small holes, which are equally spaced and symmetrically distributed on the small hole baffle, and the shape of the small holes includes a circle, and the diameter of the small holes is 0.1-10 mm.

According to an embodiment of the present invention, the diameter of the ion beam can be 15 mm, and the distance between two adjacent small holes can be 1 mm. The ion beam cannot pass through the rest of the small hole baffle, but can pass through the four small holes. That is, the ion beam will be blocked by the small hole baffle during propagation, and only the ion beam that passes through the small holes can continue to propagate.

According to an embodiment of the present invention, the pinhole baffle can limit the path of the ion beam flow, and is used to fix and determine the position where the ion beam flows through the pinhole, namely the first position, and provide comparative position information for the processing module to generate ion beam divergence angle information.

According to an embodiment of the present invention, the plate material of the small hole baffle may be a plate material of stainless steel. The stainless steel plate has the characteristics of low cost and it is easy to process small holes thereon.

FIG. 2 is a schematic diagram showing the position distribution of small holes on a small hole baffle according to an embodiment of the present invention.

As shown in FIG2 , based on a stainless steel plate, four symmetrical small holes 121 are processed on the small hole baffle 120 according to a square geometric configuration by using precision drilling technology, and each small hole is located at the vertex position of the square, so that the position where the ion beam passes through the small hole baffle can be intuitively determined. The position where the ion beam hits the microchannel plate (MCP) after passing through the small hole 2 is the second position a ₂ .

According to an embodiment of the present invention, by using the small holes that are equally spaced and symmetrically distributed on the small hole baffle, the position where the ion beam passes through the small hole, i.e., the first position, can be determined, thereby accurately controlling the path of the ion beam and ensuring that the ion beam can maintain a predetermined propagation direction after passing through the small hole.

According to an embodiment of the present invention, the microchannel plate has the advantages of high gain, fast response, low noise, high spatial resolution and small size, and can be used to multiply and amplify photoelectron signals and convert ion beam information into electron cloud signals, which can be received by the anode plate.

According to an embodiment of the present invention, the microchannel plate can be made of a solid material, such as a round glass sheet with a thickness of millimeters, and its surface is continuous and uniform, which can ensure the continuous transmission of electrons. Millions of microporous channels are evenly distributed on the microchannel plate, and each microporous channel can be regarded as an independent electron multiplication channel, which can independently amplify electrons. The diameter of the microporous channel can be in the micron level. The microchannel plate can have a large effective area to cover a larger spatial range, facilitate the reception and amplification of more electrons, and improve the signal intensity and detection sensitivity generated by the ion beam.

According to an embodiment of the present invention, when ions hit a microchannel plate, the ions will generate secondary electrons on the inner wall of the channel of the microchannel plate. These secondary electrons are accelerated by the electric field and collide with other channel walls in the channel to generate more secondary electrons, thereby achieving electron multiplication. This process is repeated in each channel, and finally an observable electron cloud signal is generated.

FIG. 3 is a schematic diagram showing a flight trajectory of an ion beam according to an embodiment of the present invention.

As shown in FIG3 , the first end point of the real flight trajectory j ₁ of the ion beam, i.e., the position where the ion beam passes through the small hole, is the first position a ₁ , and the second end point, i.e., the position where the ion beam hits the microchannel plate, is the second position a ₂ . Due to the divergence angle of the ion beam, the second position a ₂ does not coincide with the position a ₃ of the horizontal projection of the first position a ₁ on the microchannel plate. The second distance s ₂ is obtained based on the distance between the position a ₃ of the horizontal projection of the first position a ₁ on the microchannel plate and the second position a ₂ . The calculation formula of the second distance s ₂ can be shown in the following formula (1):

(1)

According to an embodiment of the present invention, a first distance s ₁ can be obtained based on the spacing between the microchannel plate and the small hole baffle plate. The first distance s ₁ can be 1-2 mm.

The calculation formula of the ion beam divergence angle can be shown as follows (2):

(2)

Where: θ is the ion beam divergence angle.

According to an embodiment of the present invention, the microchannel plate includes a first microchannel plate and a second microchannel plate, and the first microchannel plate and the second microchannel plate are stacked.

As shown in Fig. 3, according to an embodiment of the present invention, the microchannel plate 130 includes a first microchannel plate 131 and a second microchannel plate 132, and the stacking manner between the first microchannel plate 131 and the second microchannel plate 132 is a "V"-shaped stacking. Based on the first microchannel plate 131 and the second microchannel plate 132, the gain of the microchannel plate 130 can be ¹⁰⁶ ~ ¹⁰⁷ .

According to an embodiment of the present invention, due to the angular divergence problem of the ion beam, the position where the ion beam hits the microchannel plate after passing through the small hole of the small hole baffle, i.e., the second position, deviates from the position where the ion beam passes through the small hole, i.e., the horizontal projection of the first position on the microchannel plate. The second distance can be obtained based on the spacing between the position of the horizontal projection of the first position on the microchannel plate and the second position.

According to the embodiment of the present invention, based on the stacked first microchannel plate and the second microchannel plate, the electron multiplication gain can be improved, thereby enhancing the signal strength, and improving the sensitivity and signal-to-noise ratio of the ion beam divergence angle measurement device. Moreover, the stacked first microchannel plate and the second microchannel plate can simplify the structure of the ion beam divergence angle measurement device, making the entire device more compact and easy to integrate into various ion beam divergence angle measurement systems.

According to an embodiment of the present invention, the spacing between the plurality of anode strips of the anode plate is 100-500 μm.

According to the embodiment of the present invention, the anode surface can be manufactured based on the gold immersion process to obtain an anode plate. The anode plate has the characteristics of good conductivity, high reliability and low cost.

According to an embodiment of the present invention, the anode plate can be used to collect electron cloud signals and convert the electron cloud signals into electrical signals. The anode plate can include a plurality of anode strips that are equally spaced and horizontally arranged in parallel, and the number of anode strips can be 32, 64 or 128.

According to an embodiment of the present invention, the spacing between the anode strips can be 100-500 μm, so that the anode plate can achieve a position resolution of 100-500 μm. For example, the electron cloud signals of two ion events 200 μm apart on the anode plate fall on two adjacent anode strips respectively, and the anode plate can recognize that the two ion events are independent and come from different ion impact points. The ion event can be a single or a series of events in which ions in the ion beam hit the anode plate and generate electron cloud signals.

FIG. 4 shows a schematic structural diagram of an anode strip according to an embodiment of the present invention.

As shown in Fig. 4, a plurality of anode strips may be arranged at equal intervals on the anode plate 140 in a single dimension, for example, a plurality of anode strips may be arranged at equal intervals along the length direction of the anode plate. The number of anode strips 141 may be 32, 64 or 128.

According to an embodiment of the present invention, a plurality of anode strips may also be arranged on the anode plate at equal intervals in a two-dimensional dimension. A plurality of anode strips are divided into a first group of anode strips and a second group of anode strips. The two groups of anode strips form an orthogonal anode strip array. Among them, the first group of anode strips may be arranged at equal intervals along the X-axis direction, and the number of anode strips in the first group may be 64. The second group of anode strips may be arranged at equal intervals along the Y-axis direction, and the number of anode strips in the second group may also be 64. The spacing between the plurality of anode strips in the first group of anode strips and the spacing between the plurality of anode strips in the second group of anode strips may be 300-500 μm, so that the anode plate achieves a position resolution of 100-200 μm.

According to an embodiment of the present invention, the anode plate may transmit the electrical signal to the processing module via an electronic connector, wherein the electronic connector may include a high-density connector.

According to the embodiment of the present invention, the measurement accuracy of the ion beam divergence angle and the position resolution that can be achieved by the anode plate have a positive correlation. The anode plate of the embodiment of the present invention can achieve a high position resolution of micrometer level, thereby improving the measurement accuracy of the ion beam divergence angle to within 0.1 degree.

FIG5 shows a schematic structural diagram of a processing module according to an embodiment of the present invention.

As shown in FIG. 5 , the processing module 150 includes a multi-channel ASIC (Application-Specific Integrated Circuit) 151 , an FPGA (Field-Programmable Gate Array) 152 and a power supply module 153 .

According to an embodiment of the present invention, a multi-channel ASIC is an integrated circuit designed for a specific application or task. Compared with a traditional general-purpose integrated circuit, a multi-channel ASIC can provide higher performance and efficiency in a specific application, and has the characteristics of high counting rate, large number of channels, small size, high integration, etc.

According to an embodiment of the present invention, the multi-channel ASIC may be a MaPMT_v20 chip, which may convert optical signals into electrical signals. In an ion beam divergence angle measurement device, the MaPMT_v20 chip may receive secondary electron cloud signals generated by the ion beam impacting the anode plate, and convert these signals into electrical signals.

According to an embodiment of the present invention, the processing module includes a power module, and the power module is used to generate power required by the microchannel plate and power required by the processing module.

According to the embodiment of the present invention, the power module can be integrated into the processing module, and the power module has the characteristics of small size and high integration.

According to an embodiment of the present invention, the power module may be composed of a high voltage chip and a DC power chip. The power module may provide the negative high voltage power required by the microchannel plate, and may also provide the DC power required by the processing module.

According to the embodiment of the present invention, the power module can provide stable and accurate power, which is conducive to the microchannel plate to achieve high gain and the processing module to achieve accurate data processing. In addition, the design of the power module can reduce additional external connections and space occupation, making the processing module compact and easy to install and maintain.

According to an embodiment of the present invention, the processing module further includes a signal amplifying circuit and a filtering circuit, wherein the signal amplifying circuit is used to amplify the electrical signal, and the filtering circuit is used to shape and filter the amplified electrical signal.

According to an embodiment of the present invention, the signal amplification circuit and the filtering circuit may be integrated in a multi-channel ASIC.

According to the embodiments of the present invention, based on the signal amplification circuit and the filtering circuit, the electrical signal can be processed quickly and effectively, and the loss and delay of the electrical signal during the transmission process can be reduced. Moreover, the filtering circuit can shape and filter the amplified electrical signal, which helps to remove noise and irregular signals, thereby improving the quality and reliability of the signal.

According to an embodiment of the present invention, the processing module includes a discrimination submodule, which is used to distinguish between noise events and events in which electron cloud signals formed by the ion beam passing through the microchannel plate hit the anode plate.

According to an embodiment of the present invention, the identification submodule may also be integrated into a multi-channel ASIC.

According to an embodiment of the present invention, in the measurement process of the ion beam divergence angle, in addition to the signal generated by the event of the electron cloud signal formed by the ion beam passing through the microchannel plate hitting the anode plate, there will also be a noise signal generated by the noise event. The discrimination submodule can judge whether the signal is a valid event of the electron cloud signal formed by the ion beam passing through the microchannel plate hitting the anode plate by comparing the signal strength with a preset threshold. Only when the signal strength exceeds the threshold, the event will be considered a valid event, otherwise it will be judged as a noise event.

According to an embodiment of the present invention, the processing module may further include a digital-to-analog converter DAC, which may be controlled by an FPGA to output a threshold voltage and provide the threshold voltage to a discrimination submodule. Based on the threshold voltage, the discrimination submodule may determine whether the received signal exceeds a specific intensity level, that is, whether it exceeds the threshold voltage, and perform subsequent processing. For example, the discrimination submodule determines that the voltage of the received signal is greater than or equal to the threshold voltage provided by the DAC, and outputs a digital signal 1, corresponding to an event in which an electron cloud signal formed by the ion beam passing through the microchannel plate hits the anode plate. The discrimination submodule determines that the voltage of the received signal is less than the threshold voltage provided by the DAC, and outputs a digital signal 0, corresponding to a noise event.

According to an embodiment of the present invention, a threshold voltage can be set through a discrimination submodule so that the ion beam divergence angle measuring device can effectively identify the signal generated by the electron cloud signal formed by the ion beam passing through the microchannel plate hitting the anode plate, thereby improving the accuracy of signal recognition.

According to an embodiment of the present invention, the FPGA is pre-burned with a pre-written hardware logic code, which can generate ion beam divergence angle information based on the signal output by the multi-channel ASIC, the count rate of the event of the electron cloud signal formed by the ion beam passing through the microchannel plate hitting the anode plate, the first distance and the second distance of the ion beam in the electrical signal, based on formula (2).

According to an embodiment of the present invention, the ion beam divergence angle measurement device further includes an interaction module, and the interaction module is used to display the ion beam divergence angle information generated by the processing module.

According to an embodiment of the present invention, the interaction module may include a communication submodule. The communication submodule may be a serial communication interface module using the RS-485 standard. The communication submodule may transmit the received ion beam divergence angle information data packet sent by the FPGA to the interaction module based on the serial communication protocol.

According to an embodiment of the present invention, after the interactive module receives the ion beam divergence angle information data packet sent by the FPGA, it can further interact with the data based on the processor or single-chip microcomputer, as well as the on-chip system such as the programmable logic device, so as to display the divergence angle information of the ion beam in real time on the interactive interface, that is, to visualize the divergence angle information of the ion beam. Moreover, the user can modify the parameters of the multi-channel ASIC based on the interactive module through the interactive interface, control the FPGA, select the working mode, set the threshold voltage required for the discrimination submodule, control the gain of the signal amplification circuit, and adjust the filtering parameters of the filtering circuit.

According to an embodiment of the present invention, ion beam divergence angle information can be displayed in real time on an interactive interface based on an interactive module, and multi-channel ASIC and other circuit parameters can be modified directly on the interactive interface based on the interactive module, thereby improving the use flexibility of the ion beam divergence angle measurement device.

FIG. 6 shows a flow chart of a method for measuring an ion beam divergence angle according to an embodiment of the present invention.

As shown in FIG. 6 , the ion beam divergence angle measurement method of this embodiment includes operations S610 to S650 .

In operation S610, an ion beam is obtained through an ion source.

In operation S620, a first position of a position where an ion beam passes through an aperture is obtained by an aperture baffle.

In operation S630, ions in the ion beam are amplified by the microchannel plate to generate an electron cloud signal, and a second position is obtained based on a position where the ion beam hits the microchannel plate.

In operation S640, the electron cloud signal is collected through the anode plate and converted into an electrical signal.

In operation S650, the processing module generates ion beam divergence angle information based on the first distance and the second distance of the ion beam in the electrical signal, wherein the first distance is obtained based on the spacing between the microchannel plate and the pinhole baffle, and the second distance is obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position.

According to an embodiment of the present invention, an ion source may be started to generate an ion beam, and the ion source is activated to generate charged particles to form a directional ion beam.

According to an embodiment of the present invention, a plurality of evenly distributed small holes are designed on the small hole baffle, and the small hole baffle is used to obtain the position where the ion beam passes through the small hole, that is, the first position.

According to an embodiment of the present invention, the ion beam passing through the small hole on the small hole baffle will hit the microchannel plate, and the position where the ion beam hits the microchannel plate is the second position. The first distance can be obtained based on the spacing between the microchannel plate and the small hole baffle, and the second distance can be obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position. The microchannel plate will amplify the secondary electrons generated by the ion impact to form an electron cloud signal.

According to an embodiment of the present invention, the anode plate includes a plurality of anode strips, and electron cloud signals can be collected based on the anode plate and converted into electrical signals.

According to an embodiment of the present invention, the processing module receives the electrical signals collected by the anode plate, and generates the divergence angle information of the ion beam based on the first distance and the second distance information of the ion beam in these signals.

According to the embodiments of the present invention, based on the initial position of the ion beam flow limited by the pinhole baffle, the electron amplification effect of the microchannel plate and the precise signal acquisition capability of the anode plate, the measurement accuracy of the ion beam divergence angle can be improved. Based on the data processing function of the processing module, the ion beam divergence angle information is generated, which reduces the complexity of human intervention and data processing, and is conducive to improving the measurement accuracy of the ion beam divergence angle.

It will be appreciated by those skilled in the art that the features described in the various embodiments and/or claims of the present invention may be combined and/or combined in various ways, even if such combinations and/or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and/or claims of the present invention may be combined and/or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and/or combinations fall within the scope of the present invention.

The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims (9)

1. An ion beam divergence angle measuring device, comprising: An ion source for generating an ion beam; A small hole baffle, comprising a plurality of small holes, for limiting the path of the ion beam, wherein the position where the ion beam passes through the small holes is a first position; A microchannel plate is used to amplify ions in the ion beam to generate an electron cloud signal; the position where the ion beam hits the microchannel plate is the second position; an anode plate, comprising a plurality of anode strips distributed at equal intervals, wherein the intervals between the plurality of anode strips are 100-500 μm; the anode plate is used to collect the electron cloud signal and convert the electron cloud signal into an electrical signal; and A processing module, generating ion beam divergence angle information based on the first distance and the second distance of the ion beam in the electrical signal; The first distance is obtained based on the spacing between the microchannel plate and the pinhole baffle, and the second distance is obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position. 2. The ion beam divergence angle measuring device according to claim 1 is characterized in that the pinhole baffle comprises 4 pinholes, the 4 pinholes are equidistant and symmetrically distributed on the pinhole baffle, the shape of the pinholes comprises a circle, and the diameter of the pinholes is 0.1-10 mm. 3 . The ion beam divergence angle measuring device according to claim 1 , wherein the microchannel plate comprises a first microchannel plate and a second microchannel plate, and the first microchannel plate and the second microchannel plate are stacked. 4. The ion beam divergence angle measuring device according to claim 1 is characterized in that the processing module includes a discrimination submodule, and the discrimination submodule is used to distinguish between noise events and events in which the electron cloud signal formed by the ion beam passing through the microchannel plate hits the anode plate. 5. The ion beam divergence angle measuring device according to claim 4 is characterized in that the processing module also includes a signal amplification circuit and a filtering circuit, wherein the signal amplification circuit is used to amplify the electrical signal, and the filtering circuit is used to shape and filter the amplified electrical signal. 6 . The ion beam divergence angle measuring device according to claim 1 , wherein the processing module further comprises a power module, and the power module is used to generate power required by the microchannel plate and power required by the processing module. 7 . The ion beam divergence angle measuring device according to claim 1 , further comprising an interaction module, wherein the interaction module is used to display the ion beam divergence angle information generated by the processing module. 8 . The ion beam divergence angle measuring device according to claim 1 , wherein the energy of the ion beam generated by the ion source is 250-5000 eV. 9. A method for measuring an ion beam divergence angle, comprising: An ion beam current is obtained through an ion source; Obtaining a first position of the ion beam passing through the aperture through a small aperture baffle; amplifying ions in the ion beam through a microchannel plate to generate an electron cloud signal, and obtaining a second position based on a position where the ion beam hits the microchannel plate; Collecting the electron cloud signal through an anode plate and converting the electron cloud signal into an electrical signal; and Through the processing module, ion beam divergence angle information is generated based on the first distance and the second distance of the ion beam in the electrical signal; wherein the spacing between the multiple anode strips of the anode plate is 100-500 μm; the first distance is obtained based on the spacing between the microchannel plate and the pinhole baffle, and the second distance is obtained based on the spacing between the horizontal projection position of the first position on the microchannel plate and the second position.