Spectrometer for measuring the energy distribution of cold plasma

Abstract

The present invention provides a spectrometer for measuring the energy distribution of cold plasma, which can be applied to the field of ionospheric plasma detection technology. The spectrometer includes: a first grounded housing provided with an inlet channel; a hemispherical structure housing in the second grounded housing is provided with a first channel aperture on its hemispherical surface, and a first circular ring structure housing is provided with a second channel aperture; a first uniform electric field generated by a first bias electrode generates a first edge overflow field between the first circular ring structure housing and the top of the first grounded housing through the second channel aperture; a second bias electrode has a pore at the bottom center position of its hemispherical structure electrode, and a third channel aperture on its hemispherical surface. A second uniform electric field generated by the second bias electrode generates a second edge overflow field between the hemispherical structure housing and the top of the first grounded housing through the first channel aperture. The inside of the hemispherical structure electrode is a field-free drift region; an energy distribution determination system is used to determine the energy distribution information of the received cold plasma.

Description

Technical Field

[0001] The present invention relates to the technical field of ionospheric plasma detection, and particularly to a spectrometer for measuring the energy distribution of cold plasma. Background Art

[0002] The ionosphere exists in the upper atmosphere of the Earth and other planets and satellites. In this region, atmospheric molecules and atoms are ionized under the action of solar radiation and cosmic rays, generating free electrons and ions, thus forming a plasma state. Since the ionospheres of the Earth and other planets and satellites are closely related to daily life, it is crucial to understand the energy and material activities of the ionosphere.

[0003] Background cold plasma is the main component of the ionosphere, and its various data play an important role in understanding the state and activities of the ionosphere. Therefore, an important part of ionospheric measurement is the measurement of background cold plasma therein.

[0004] Cold plasma in the ionosphere has the characteristics of extremely low energy and high density, but the limitation of the minimum voltage provided by the available power supply on the satellite is not applicable to detecting extremely low-energy cold plasma in the ionosphere. Therefore, the complete detection of the energy distribution of cold plasma, the main component in the ionosphere, is a technical problem to be solved in ionospheric detection. Summary of the Invention

[0005] In view of the above problems, the present invention provides a spectrometer for measuring the energy distribution of cold plasma, including:

[0006] A first grounded housing provided with an inlet channel;

[0007] A second grounded housing including a hemispherical structure housing, a first circular ring structure housing, and a second circular ring structure housing. A first channel aperture is provided on the hemispherical surface of the hemispherical structure housing, and a second channel aperture is provided on the first circular ring structure housing;

[0008] A first bias electrode located between the first circular ring structure housing and the second circular ring structure housing. A first uniform electric field generated by the first bias electrode generates a first edge overflow field between the first circular ring structure housing and the top of the first grounded housing through the second channel aperture;

[0009] A second bias electrode including a hemispherical structure electrode. A pore is provided at the center of the bottom of the hemispherical structure electrode, and a third channel aperture is provided on the hemispherical surface of the hemispherical structure electrode. A second uniform electric field generated by the second bias electrode generates a second edge overflow field between the hemispherical structure housing and the top of the first grounded housing through the first channel aperture. The inside of the hemispherical structure electrode is a field-free drift region;

[0010] An energy distribution determination system for determining the energy distribution information of received cold plasma; among them, the energy of the cold plasma that can sequentially pass through the above-mentioned inlet channel, the above-mentioned first edge overflow field, the above-mentioned second edge overflow field, the above-mentioned second uniform electric field, the above-mentioned field-free drift region, and the above-mentioned pore and enter the energy distribution determination system meets a preset condition.

[0011] According to the spectrometer for measuring the energy distribution of cold plasma provided by the present invention, the uniform electric fields generated by the first bias electrode and the second bias electrode do not directly act on the path of the cold plasma, but act on the path of the cold plasma entering the spectrometer through the first edge overflow field and the second edge overflow field generated by the second channel aperture and the first channel aperture in the second grounded housing. Since the electric fields in the first edge overflow field and the second edge overflow field are very weak, it is possible to deflect extremely low-energy cold plasma so that the energy distribution determination system can collect extremely low-energy cold plasma. Thus, the energy distribution of extremely low-energy cold plasma can be determined based on the energy distribution determination system. Therefore, this spectrometer can be applied to the extremely low-energy and high-density ionospheric cold plasma environment and can achieve a complete measurement of the energy magnitude and direction distribution of cold plasma in the ionosphere. Description of the Drawings

[0012] Through the following description of the embodiments of the present invention with reference to the drawings, the above-mentioned content and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0013] Figure 1 Shows an application scenario diagram of a spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention.

[0014] Figure 2 Shows an internal structure diagram of a spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention.

[0015] Figure 3 Shows a schematic diagram of the internal electric field region distribution of a spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention.

[0016] Figure 4 Shows a schematic diagram of the distribution of molybdenum meshes in the spectrometer according to an embodiment of the present invention.

[0017] Figure 5 Shows a schematic diagram of the flight path of cold plasma with different energy magnitudes inside the spectrometer when the preset bias voltage is -5V according to an embodiment of the present invention.

[0018] Figure 6 Shows a schematic diagram of the potential distribution in the cold plasma deflection region when the preset bias voltage is -5V according to an embodiment of the present invention.

[0019] Figure 7 Shows a schematic diagram of the flight paths of cold plasmas with different energy levels inside the spectrometer when the preset bias voltage is -500V according to an embodiment of the present invention.

[0020] Figure 8 Shows a top-down schematic diagram of the path of the cold plasma according to an embodiment of the present invention.

[0021] Figure 9 Shows a schematic diagram of the anode plate according to an embodiment of the present invention. Detailed implementation manners

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth in order to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present invention.

[0023] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0024] All terms used herein (including technical and scientific terms) 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.

[0025] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0026] In the process of implementing the present invention, it is found that there are many in-situ space detectors that can be used to detect the ionosphere. Langmuir probes and retarding potential analyzers are the main means for detecting cold plasma in the ionosphere. By using a metal collector electrode, a large number of charged particles of incident cold plasma are collected, and a current signal is output, which can be called an "integral type" detection instrument. However, these detectors can only measure the overall isotropy of cold plasma blocks in a region, and cannot know the changes in the local anisotropy of cold plasma, such as small-scale directional movement microcurrents of ions, local heating of cold plasma, plasma local instability and other mechanisms.

[0027] The hemispherical top-hat electrostatic analyzer is also a commonly used ion detection payload with spatial resolution in space charged particle detection. It can simultaneously detect the distribution of charged particles within a 360° field of view, and has angular resolution, enabling the analysis of the incident angle of particles while performing energy analysis. It is the most commonly used instrument for measuring the energy magnitude and direction distribution of ions. However, the cold plasma in the ionosphere has the characteristics of extremely low energy and high density, and the limitation of the minimum voltage provided by the power supply on the satellite is not applicable to detecting the extremely low energy cold plasma in the ionosphere.

[0028] Therefore, a complete detection of the energy distribution of the main component cold plasma in the ionosphere is a major difficulty in ionosphere detection. For this reason, an embodiment of the present invention provides a spectrometer for measuring the energy distribution of cold plasma to detect the anisotropic energy distribution of extremely low energy cold plasma.

[0029] Figure 1 Fig. shows an application scenario diagram of a spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention.

[0030] As Figure 1 shown, the application scenario of this embodiment may include the spectrometer 101 for measuring the energy distribution of cold plasma and the on-orbit satellite 102. The spectrometer 101 for measuring the energy distribution of cold plasma and the on-orbit satellite 102 are located in the background plasma environment to measure the energy distribution of cold plasma in the background plasma environment.

[0031] According to an embodiment of the present invention, the on-orbit satellite 102 is used as a carrier, and the spectrometer 101 is used as a payload. The spectrometer 101 is used to measure the energy distribution of cold plasma in the ionosphere near the on-orbit satellite 102. Among them, the plasma environment can also be the earth's surface, planetary space, etc.

[0032] According to an embodiment of the present invention, the spectrometer 101 can measure a 360° plane at a fixed position. By coupling the position of the spectrometer 101 on the orbiting satellite 102 and the spinning mode of the orbiting satellite 102, that is, the spectrometer 101 moves along the orbital motion direction of the orbiting satellite 102 while rotating along the orbital axis of the orbiting satellite 102, a complete imaging of the energy magnitude and direction of the cold plasma in the entire ionospheric space near the orbiting satellite 102 can be achieved. Thus, the purpose of accurately measuring the cold plasma in the ionospheric background at a small scale can be achieved, and it is also helpful to understand the local change mechanism of the ionosphere, such as the microcurrent inside the plasma, cold plasma heating, plasma local instability, etc., which plays an important role in further studying the behavior state of the cold plasma in the ionosphere.

[0033] Based on the Figure 1 scenario described below, the spectrometer for measuring the energy distribution of cold plasma according to the embodiment of the present invention will be described in detail through Figures 2 - 9 the following.

[0034] Figure 2 FIG. shows the internal structure diagram of the spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention.

[0035] According to an embodiment of the present invention, the spectrometer for measuring the energy distribution of cold plasma can be a cylindrical structure. Among them, the size of the spectrometer can be a diameter of 50 mm and a height of 30 mm, and the size of the spectrometer can also be adjusted adaptively.

[0036] According to an embodiment of the present invention, by cutting along the height direction of the cylindrical structure and through the top surface diameter, the internal structure of the spectrometer can be shown, that is, as Figure 2 shown.

[0037] As Figure 2 shown, the outside of the spectrometer is a first grounded housing, that is, the first grounded housing is a cylindrical structure, and an inlet channel is provided on the first grounded housing. Among them, the first grounded housing is mainly used to provide support and isolate external interference; the inlet channel is a circle of channels on the side of the first grounded housing, and is used for cold plasma within a 360° range in the same plane to enter the spectrometer.

[0038] According to an embodiment of the present invention, the spectrometer for measuring the energy distribution of cold plasma further includes a second grounded housing inside. The second grounded housing can include three parts: a hemispherical structure housing, a first circular ring structure housing, and a second circular ring structure housing.

[0039] According to an embodiment of the present invention, an inlet channel is disposed on the side surface of the first grounded housing corresponding to the top of the first grounded housing and the first circular ring structure housing, and the inlet channel is an annular channel disposed on the side surface of the first grounded housing.

[0040] Among them, in the order from top to bottom of the internal structure of the spectrometer, the first circular ring structure housing is located above the second circular ring structure housing; a first channel aperture is provided on the hemispherical surface of the hemispherical structure housing, and the first channel aperture is between the top of the first grounded housing and the first circular ring structure housing, and the first circular ring structure housing is provided with a second channel aperture.

[0041] Among them, the thickness of the first grounded housing and the second grounded housing can be set between 1 mm and 1.5 mm to be light enough while ensuring a certain thickness of the grounded housing; both the first grounded housing and the second grounded housing maintain the ground potential or the potential of the satellite payload surface.

[0042] Among them, for example, the thickness of the hemispherical structure housing in the second grounded housing can be 1 mm, and the inner and outer radii of the hemispherical structure housing can be 15 mm and 16 mm.

[0043] According to an embodiment of the present invention, the spectrometer for measuring the energy distribution of cold plasma further includes a first bias electrode and a second bias electrode. The first bias electrode is a circular ring structure, and the first bias electrode is located between the first circular ring structure housing and the second circular ring structure housing. Among them, the first bias electrode can be set as a circular ring structure with an inner radius of 20 mm, an outer radius of 22 mm, and a thickness of 1 mm; the thickness of the hemispherical structure electrode in the second bias electrode can be set to 0.5 mm, and the inner and outer radii of the hemispherical structure electrode can be 10.5 mm and 11 mm.

[0044] Figure 3 The schematic diagram of the internal electric field region distribution of the spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention is shown.

[0045] According to an embodiment of the present invention, by applying a voltage to the first bias electrode, a first uniform electric field is generated by the first bias electrode between the first circular ring structure housing and the second circular ring structure housing, that is, a first uniform electric field is generated in the region 310 shown in Figure 3 The first uniform electric field generated by the first bias electrode will generate a first edge overflow field between the first circular ring structure housing and the top of the first grounded housing through the second channel aperture, that is, a first edge overflow field is generated in the region 320 shown in Figure 3 the first edge overflow field is generated in the region 320 shown in

[0046] Among them, the second channel aperture above the first bias electrode is used to control the overflow of the first uniform electric field. The size of the second channel aperture can be, for example, a thickness of 1 mm, a width of 1 mm from the lower surface, and gradually increasing to a width of 2 mm at the upper surface.

[0047] According to an embodiment of the present invention, the second bias electrode may include a hemispherical structure electrode portion. Among them, the hemispherical structure electrode may be set as a hemispherical structure with a thickness of 0.5 mm.

[0048] According to an embodiment of the present invention, the diameter of the hemispherical structure electrode is smaller than the diameter of the hemispherical structure housing, that is, in the internal structure of the spectrometer, the hemispherical structure electrode is located directly below the hemispherical structure housing; a pore is provided at the bottom center position of the hemispherical structure electrode, and a third channel aperture is provided on the hemispherical surface of the hemispherical structure electrode.

[0049] According to an embodiment of the present invention, by applying a voltage to the second bias electrode, a second uniform electric field is generated between the hemispherical structure electrode and the hemispherical structure housing by the second bias electrode, that is, Figure 3 a second uniform electric field is generated in the region 340 shown in, and the second uniform electric field generated by the second bias electrode will generate a second edge overflow field between the hemispherical structure housing and the top of the first grounded housing through the first channel aperture, that is, Figure 3 a second edge overflow field is generated in the region 330 shown in, and the inside of the hemispherical structure electrode is a field-free drift region, that is, Figure 3 the region 350 shown in is a field-free drift region.

[0050] Based on the above content, it can be seen that the second grounded housing in the spectrometer can be used to adjust the electric field configuration inside the spectrometer, that is, the spectrometer is divided into a first uniform electric field, a second uniform electric field, a first edge overflow field, and a second edge overflow field based on the second grounded housing.

[0051] Among them, the first grounded housing, the second grounded housing, the first bias electrode, and the second bias electrode can all be made of aluminum alloy material, and can also be made of titanium alloy material, that is, materials with good electrical conductivity and relatively small density can all be selected.

[0052] According to an embodiment of the present invention, the spectrometer for measuring the energy distribution of cold plasma further includes an energy distribution determination system. As Figure 2 shown, the energy distribution determination system is located directly below the second bias electrode to determine the energy distribution information of the received cold plasma; among them, the energy of the cold plasma that can sequentially pass through the entrance channel, the first edge overflow field, the second edge overflow field, the second uniform electric field, the field-free drift region, and the pore and enter the energy distribution determination system satisfies a preset condition.

[0053] Among them, the energy distribution information may include the energy magnitude and energy direction of the cold plasma.

[0054] As Figure 2 shown in , the centers of the first grounded housing, the second grounded housing, the first bias electrode, the second bias electrode, and the energy distribution determination system in the spectrometer for measuring the energy distribution of cold plasma are on the same straight line.

[0055] According to an embodiment of the present invention, the uniform electric fields generated by the first bias electrode and the second bias electrode do not directly act on the path of the cold plasma, but act on the path of the cold plasma entering the spectrometer through the first edge overflow field and the second edge overflow field generated by the second channel aperture and the first channel aperture in the second grounded housing. Since the electric fields in the first edge overflow field and the second edge overflow field are very weak, it is possible to deflect extremely low-energy cold plasma so that the energy distribution determination system can collect extremely low-energy cold plasma. Thus, the energy distribution of the extremely low-energy cold plasma can be determined based on the energy distribution determination system. Therefore, this spectrometer can be applied to the ionospheric cold plasma environment with extremely low energy and high density, and can achieve a complete measurement of the energy magnitude and direction distribution of cold plasma in the ionosphere.

[0056] According to an embodiment of the present invention, the energy distribution determination system includes a microchannel plate collection system and an anode plate; the microchannel plate collection system is used to collect the cold plasma passing through the pores and accelerate the collected cold plasma to generate an electron cloud; the anode plate is used to count the electron cloud and determine the energy direction of the cold plasma corresponding to the electron cloud; among them, the energy distribution information includes the energy direction and energy magnitude of the cold plasma.

[0057] According to an embodiment of the present invention, the energy distribution determination system may include a microchannel plate collection system and an anode plate, where the anode plate may be a discrete anode plate.

[0058] According to an embodiment of the present invention, as Figure 2 shown in , the cold plasma entering the spectrometer needs to pass through the first channel aperture, the third channel aperture, and the pores in sequence before being collected by the energy distribution determination system. The microchannel plate collection system is used to collect the cold plasma passing through the pores and accelerate the collected cold plasma to generate an electron cloud.

[0059] According to an embodiment of the present invention, after the microchannel plate collection system generates an electron cloud, the anode plate counts the generated electron cloud and determines the angles of each electron cloud to determine the energy direction of the corresponding cold plasma, where the energy direction may characterize the direction in which the cold plasma enters the spectrometer.

[0060] Among them, the incident surface of the microchannel plate collection system can maintain a bias voltage of more than -2000V to accelerate the cold plasma to the energy for generating an electron cloud. For example, the incident surface of the microchannel plate collection system can maintain a bias voltage of -4000V.

[0061] According to an embodiment of the present invention, for the cold plasma that sequentially passes through the first channel aperture, the third channel aperture, and the pore and enters the energy distribution determination system, the energy distribution determination system can perform angular resolution measurement on the energy direction of the cold plasma.

[0062] According to an embodiment of the present invention, the energy spectrometer further includes a first molybdenum mesh, which is located between the inlet channel and the first channel aperture and is used to isolate the first edge overflow field and the second edge overflow field; wherein, the first molybdenum mesh is connected to the first grounded housing and the first circular ring structure housing to ensure that the potential of the first molybdenum mesh is consistent with that of the grounded housing, and the cold plasma enters the second edge overflow field from the first edge overflow field through the first molybdenum mesh.

[0063] According to an embodiment of the present invention, the energy spectrometer further includes a second molybdenum mesh, a third molybdenum mesh, and a fourth molybdenum mesh; the second molybdenum mesh is located at the third channel aperture and is used to ensure that the spherical gap electric field between the hemispherical structure electrode and the hemispherical structure housing is a uniform electric field to obtain a second uniform electric field; the third molybdenum mesh is located at the pore and is used to ensure that the field-free drift region inside the hemispherical structure electrode is not damaged while ensuring that the cold plasma passes through; the fourth molybdenum mesh is located between the bottom of the hemispherical structure electrode and the microchannel plate collection system and is used to isolate the voltage of the microchannel plate collection system.

[0064] According to an embodiment of the present invention, the internal structure of the energy spectrometer further includes a first molybdenum mesh, a second molybdenum mesh, a third molybdenum mesh, and a fourth molybdenum mesh.

[0065] Figure 4 The distribution schematic diagram of the molybdenum mesh in the energy spectrometer according to an embodiment of the present invention is shown.

[0066] According to an embodiment of the present invention, the first molybdenum mesh is located between the inlet channel and the first channel aperture and is connected to the first grounded housing and the first circular ring structure housing, as Figure 4 the position of the first molybdenum mesh is located; the first molybdenum mesh isolates the first edge overflow field and the second edge overflow field, that is, as Figure 3 shown, the first molybdenum mesh isolates region 330 and region 320, so that the cold plasma needs to pass through the first molybdenum mesh to enter the second edge overflow field from the first edge overflow field.

[0067] According to an embodiment of the present invention, the second molybdenum mesh is located at the third channel aperture, as Figure 4 the position of the second molybdenum mesh is located, to ensure that the spherical gap electric field between the hemispherical structure electrode and the hemispherical structure housing is a uniform electric field, that is, to ensureFigure 3 The electric field generated by the region 350 shown is a uniform electric field.

[0068] According to an embodiment of the present invention, the third molybdenum mesh is located at the pore, as Figure 4 the position of the third molybdenum mesh shown, to ensure that the cold plasma can pass through while not damaging the field-free drift region inside the hemispherical structure electrode in the second bias electrode.

[0069] According to an embodiment of the present invention, the fourth molybdenum mesh is located between the bottom of the hemispherical structure electrode and the microchannel plate collection system, as Figure 4 the position of the fourth molybdenum mesh shown; since the incident surface of the microchannel plate collection system maintains a bias voltage of more than -2000V, the fourth molybdenum mesh can be used to isolate the voltage of the microchannel plate collection system, so that the cold plasma passing through the third molybdenum mesh has a longer drift distance, which is beneficial to improving the accuracy of the subsequent determined ability direction.

[0070] According to an embodiment of the present invention, the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh, and the fourth molybdenum mesh in the internal structure of the energy spectrometer are located in multiple regions of the flight path of the cold plasma inside the energy spectrometer, and act as electrostatic shielding of the conductor while allowing the cold plasma to pass smoothly, so as to isolate the first edge overflow field and the second edge overflow field, ensure that the spherical gap electric field between the hemispherical structure electrode and the hemispherical structure housing is a uniform electric field, ensure that the field-free drift region inside the hemispherical structure electrode is not damaged, and isolate the voltage of the microchannel plate collection system.

[0071] According to an embodiment of the present invention, the transmittance of the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh, and the fourth molybdenum mesh is less than or equal to 0.1, which is used to weaken the ion flux of the cold plasma.

[0072] According to an embodiment of the present invention, after the cold plasma passes through the pore, it will be collected by the energy distribution determination system. However, considering that the ion flux of the ionosphere can reach 10 10 ions / (cm 2 ·s), which is higher than the counting upper limit of the energy distribution determination system, it is necessary to use a molybdenum mesh with a low transmittance to reach the counting range of the energy distribution determination system by weakening the ion flux.

[0073] Among them, the ion flux refers to the number of ions passing through per square centimeter area per unit time; the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh, and the fourth molybdenum mesh can all select molybdenum meshes with a transmittance less than or equal to 0.1.

[0074] For example, when the transmittance of the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh, and the fourth molybdenum mesh is 0.1, since the cold plasma needs to pass through four layers of molybdenum meshes from incidence to being collected by the energy distribution determination system, the flux of the cold plasma can be reduced by 10,000 times, thus being able to meet the counting range of the energy distribution determination system.

[0075] According to an embodiment of the present invention, by using the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh, and the fourth molybdenum mesh with low transmittance, the flux of the cold plasma can be weakened, so that the weakened ion flux can meet the counting range of the energy distribution determination system, avoiding exceeding the counting upper limit of the energy distribution system to cause overuse and affecting the accuracy of counting and energy distribution information determination of the energy distribution system.

[0076] According to an embodiment of the present invention, the inlet channel is used for cold plasma with different energy levels to enter the spectrometer; the first edge overflow field is used to deflect the cold plasma passing through the inlet channel for the first time to block the cold plasma that does not meet the preset energy range from entering the second edge overflow field; the second edge overflow field is used to deflect the cold plasma entering the second edge overflow field for the second time to block the cold plasma that does not meet the preset energy range from passing through the first channel aperture and entering the second uniform electric field.

[0077] According to an embodiment of the present invention, the inlet channel can be set to have an aperture diameter of 50 microns to collect the cold plasma in the ionosphere; since the aperture of the inlet channel is relatively small, the cold plasma at a certain angle with the horizontal plane cannot pass through the inlet channel, and only the cold plasma incident along the horizontal plane can pass through the inlet channel.

[0078] According to an embodiment of the present invention, after cold plasma with different energy levels enters the spectrometer from different incident directions through the inlet channel, the cold plasma will deflect for the first time in the first edge overflow field and deflect for the second time in the second edge overflow field, so that the cold plasma that meets the preset energy range can pass through the first channel aperture and enter the second uniform electric field, where the preset energy range is related to the voltages applied to the first bias electrode and the second bias electrode.

[0079] According to an embodiment of the present invention, by deflecting the cold plasma twice based on the two edge overflow fields of the first edge overflow field and the second edge overflow field, cold plasma that does not meet the preset energy range can be further blocked, avoiding the omission of blocking cold plasma that does not meet the preset energy range due to only one deflection.

[0080] According to an embodiment of the present invention, the diameter of the hemispherical structure electrode is smaller than the diameter of the hemispherical structure housing, and the hemispherical structure electrode generates a second uniform electric field between the hemispherical structure electrode and the hemispherical structure housing; the second uniform electric field and the field-free drift region are used to enable cold plasma within a preset energy range to linearly drift through the third channel aperture to the bottom of the hemispherical structure electrode and expand the horizontal position offset brought about by the two deflections of the cold plasma.

[0081] According to an embodiment of the present invention, the cold plasma entering the second uniform electric field will then pass through the third channel aperture to the bottom of the hemispherical structure electrode. The cold plasma will linearly shift in the second uniform electric field and the field-free drift region to expand the horizontal position offset brought about by the two deflections of the cold plasma by the first edge overflow electric field and the second edge overflow electric field, where the horizontal position refers to the radial direction of the spectrometer.

[0082] Among them, the cold plasma within the preset energy range will linearly drift to the bottom of the hemispherical structure electrode, but only the cold plasma with a specific energy magnitude within the preset energy range will pass through the pores in the bottom of the hemispherical structure electrode, so that the energy distribution determination system can determine the energy distribution information of the collected cold plasma passing through the pores.

[0083] According to an embodiment of the present invention, the cold plasma deflected twice linearly drifts in the second uniform electric field and the field-free offset region to further expand the horizontal position offset brought about by the deflection, thereby improving the accuracy of the energy direction of the cold plasma determined by the energy distribution determination system.

[0084] According to an embodiment of the present invention, the double-spherical structure formed by the hemispherical structure housing and the hemispherical structure electrode is used to converge cold plasma in the same direction in the horizontal direction.

[0085] According to an embodiment of the present invention, due to the double-spherical structure formed by the hemispherical structure housing and the hemispherical structure electrode, it is possible to converge cold plasma in the same direction in the horizontal direction, which is beneficial for distinguishing the energy direction of the cold plasma.

[0086] According to an embodiment of the present invention, the voltages of the first bias electrode and the second bias electrode are both set to a preset bias voltage; the range of the preset bias voltage is -5V to -2500V.

[0087] According to an embodiment of the present invention, both the first bias electrode and the second bias electrode can generate a scanning negative bias voltage of 5V to 2500V relative to the grounded housing, and the first bias electrode and the second bias electrode are conducted and maintained at the same negative bias voltage.

[0088] According to an embodiment of the present invention, the preset condition may characterize that the energy of the cold plasma is the target energy, and the target energy is determined according to a preset bias voltage; an energy spectrometer for measuring the energy distribution of cold plasmas with different energy magnitudes by performing voltage scanning within a range of the preset bias voltage, wherein the range of the target energy is 0.01 eV to 5 eV.

[0089] According to an embodiment of the present invention, cold plasmas satisfying the preset energy range can linearly drift to the bottom of the hemispherical structure electrode in the second uniform electric field and the field-free drift region, but only cold plasmas with the target energy magnitude can be collected by the energy distribution determination system through the pores.

[0090] According to an embodiment of the present invention, the energy magnitude of the cold plasma collected by the energy distribution determination system in the energy spectrometer of the present invention has a linear relationship with the bias voltage between the first bias electrode and the second bias electrode, and this linear relationship is shown in the following formula (1).

[0091] (1);

[0092] Wherein, can represent the energy magnitude of the cold plasma, can represent the charge number, can represent the absolute value magnitude of the bias voltage between the first bias electrode and the second bias electrode, .

[0093] Based on the above formula (1), on the basis of the negative bias voltage achievable on the satellite being -5V to -2500V, the energy spectrometer of the present invention can measure cold plasmas with an energy magnitude of 0.01 eV to 5 eV, wherein the unit of E is eV (electron volt).

[0094] According to an embodiment of the present invention, based on the preset bias voltage applied to the first bias electrode and the second bias electrode, through the above formula (1), the energy magnitude of the cold plasma collected by the energy distribution determination system at this moment can be obtained.

[0095] According to an embodiment of the present invention, based on the internal structure of the energy spectrometer, the height and position of the first molybdenum mesh and the size and position of the first channel aperture and the second channel aperture on the hemispherical structure housing and the hemispherical structure electrode can be adjusted according to the path of the cold plasma inside the energy spectrometer, so as to obtain the structure as Figure 4 shown, thereby ensuring that the cold plasma with the target energy can pass through the pores at the bottom of the hemispherical structure electrode through two deflections.

[0096] Among them, since the smaller the radius of the pores at the bottom of the hemispherical structure electrode, the lower the energy resolution that can be achieved by the energy spectrometer, the radius of the pores at the bottom of the hemispherical structure electrode can be set to 0.4 mm, which is the minimum radius that can be achieved by processing.

[0097] Figure 5 Fig. shows a schematic diagram of the flight path of cold plasma with different energy levels inside the energy spectrometer when the preset bias voltage is -5V according to an embodiment of the present invention.

[0098] As Figure 5 shown, taking cold plasma with incident energy levels of 1 eV, 0.001 eV, 0.02 eV, 0.0103 eV, 0.097 eV, and 0.01 eV as examples, when the preset bias voltage of the first bias electrode and the second bias electrode is -5V, the flight paths of cold plasma with different energy levels inside the energy spectrometer. Among them, Figure 5 the voltages of each electrode have been marked in, and the unmarked electrode parts are all grounded enclosures.

[0099] Based on the above formula (1), when the preset bias voltage of the first bias electrode and the second bias electrode is -5V, it can be determined that the energy spectrometer is measuring cold plasma with an energy level of 0.01 eV.

[0100] In Figure 5 , cold plasma with different energy levels is first deflected under the influence of the electric field in the first edge overflow field, blocking cold plasma that does not meet the preset energy range from entering the second edge overflow field. That is, since the energy gaps between cold plasma with energy levels of 1 eV and 0.001 eV and the target energy of 0.01 eV are too large, they cannot pass through the first molybdenum mesh into the second edge overflow field after being deflected in the first edge overflow field.

[0101] Among them, the preset energy range can represent an energy range that is not much different from the target energy level. As Figure 5 shown, cold plasma with energy levels of 1 eV and 0.001 eV does not meet the preset energy range, while cold plasma with energy levels of 0.02 eV, 0.0103 eV, 0.097 eV, and 0.01 eV meets the preset energy range.

[0102] In Figure 5 , the cold plasma that enters the second edge overflow field will undergo a second deflection to further block cold plasma that does not meet the preset energy range and has not been successfully blocked, allowing only cold plasma that meets the preset energy range to enter the second uniform electric field.

[0103] Among them, in the first edge overflow field and the second edge field, the deflection angles of cold plasmas with different energy levels will vary; the greater the energy of the cold plasma, the smaller the degree of deflection. As Figure 5 shown in

[0104] As Figure 5 shown, the cold plasmas with energy levels of 0.02eV, 0.0103eV, 0.097eV, and 0.01eV that enter the second uniform electric field drift linearly in the second uniform electric field and the field-free drift region. The cold plasmas with energy levels of 0.02eV, 0.0103eV, and 0.097eV will linearly shift to the bottom of the hemispherical structure electrode. Only the cold plasma with an energy level of 0.01eV can pass through the pores and be collected by the energy distribution determination system.

[0105] Figure 6 shows a schematic diagram of the potential distribution in the cold plasma deflection region when the preset bias voltage is -5V according to an embodiment of the present invention.

[0106] As Figure 6 shown, the deflection region refers to the region where the first edge overflow field and the second edge overflow field are located. Figure 6 The loop shown in

[0107] is an equipotential line around the flight path of the cold plasma. According to an embodiment of the present invention, the electric fields of the first edge overflow field and the second edge overflow field are very weak, so that a sufficiently small electric field can be generated within the achievable preset bias voltage range to deflect the extremely low-energy cold plasma, thereby enabling the measurement of the extremely low-energy cold plasma.

[0108] Figure 7 shows a schematic diagram of the flight paths of cold plasmas with different energy levels inside the spectrometer when the preset bias voltage is -500V according to an embodiment of the present invention.

[0109] As Figure 7 shown, taking the incident cold plasmas with energy levels of 5eV, 0.1eV, 0.01eV, 2.5eV, 1.03eV, 0.97eV, and 1eV as examples, when the preset bias voltages of the first bias electrode and the second bias electrode are -500V, the flight paths of the cold plasmas with different energy levels inside the spectrometer are shown. Among them, Figure 7 the voltages of each electrode have been marked, and the unmarked electrode parts are all grounded enclosures.

[0110] Based on the above formula (1), when the preset bias voltages of the first bias electrode and the second bias electrode are -500V, it can be determined that the spectrometer is measuring cold plasma with an energy of 1eV.

[0111] In Figure 7 , cold plasma of each energy size is first deflected by the electric field in the first edge overflow field, blocking cold plasma that does not meet the preset energy range from entering the second edge overflow field. That is, due to the large energy gap between the cold plasma with energy sizes of 5eV, 0.1eV, and 0.01eV and the target energy of 1eV, it cannot pass through the first molybdenum mesh into the second edge overflow field after being deflected in the first edge overflow field.

[0112] Among them, as Figure 5 shows, the cold plasma with energy sizes of 5eV, 0.1eV, and 0.01eV does not meet the preset energy range, while the cold plasma with energy sizes of 2.5eV, 1.03eV, 0.97eV, and 1eV meets the preset energy range.

[0113] In Figure 7 , the cold plasma entering the second edge overflow field will undergo a second deflection to further block the cold plasma that does not meet the preset energy range and has not been successfully blocked, allowing only the cold plasma that meets the preset energy range to enter the second uniform electric field.

[0114] Among them, as Figure 5 shows, the cold plasma with an energy size of 5eV has a small deflection degree and thus hits the first grounded outer shell after deflection, and the cold plasma with energy sizes of 0.1eV and 0.01eV has a small deflection degree and thus hits the first ring structure outer shell after deflection.

[0115] As Figure 7 shows, the cold plasma with energy sizes of 2.5eV, 1.03eV, 0.97eV, and 1eV entering the second uniform electric field drifts linearly in the second uniform electric field and the field-free drift region. The cold plasma with energy sizes of 2.5eV, 1.03eV, and 0.97eV will linearly shift to the bottom of the hemispherical structure electrode, and only the cold plasma with an energy size of 1eV can pass through the pores to be collected by the energy distribution determination system.

[0116] In Figure 5 and Figure 7 , after changing the preset bias voltage to -500V, Figure 7 the path of the cold plasma with an energy size of 1eV in Figure 5The path of the cold plasma with an energy of 0.01 eV coincides, but the path between the fourth molybdenum mesh and the energy distribution determination system does not coincide. The path of the cold plasma between the fourth molybdenum mesh and the energy distribution determination system depends on the energy of the cold plasma itself.

[0117] Take Figure 5 and Figure 7 as an example. The cold plasma that does not meet the preset energy range cannot enter the second uniform electric field due to two deflections in the first edge overflow field and the second edge field. The actual energies of the ions collected by the energy distribution determination system are between 0.097 eV and 0.013 eV and between 0.97 eV and 1.03 eV respectively. That is, the energy resolution of the spectrometer of the present invention can reach within 6%, enabling good energy resolution performance at extremely low energies. Moreover, the design of other geometric structures inside the spectrometer makes the direct action of the electrodes on the cold plasma in other regions except the deflection region a uniform field, which will not affect the path deflection of the cold plasma with extremely low energy. Therefore, it can achieve Figure 5 and Figure 7 energy resolution level.

[0118] Figure 8 FIG. shows a top view schematic diagram of the path of the cold plasma according to an embodiment of the present invention.

[0119] As Figure 8 shown, it is a top view flight path of cold plasmas with the same energy at different incident angles inside the spectrometer. Among them, for the cold plasmas incident in a certain area range, only a part can be collected by the microchannel plate collection system and converge to a point in the microchannel plate collection system. Then, the cold plasmas incident in this area range can be regarded as having the same incident angle. The microchannel plate collection system can also be called a microchannel plate.

[0120] Figure 9 FIG. shows a schematic diagram of the anode plate according to an embodiment of the present invention.

[0121] As Figure 9 shown, the anode plate can be a discrete anode plate. The anode plate includes a plurality of anode blocks, and each anode block corresponds to an angular range. The anode plate has an angular resolution function to determine the energy direction of the cold plasma. The PCB insulating bracket is used to provide stable mechanical support for the anode plate to ensure that the anode plate is fixed in the spectrometer.

[0122] According to an embodiment of the present invention, the positions where cold plasmas with different incident angles finally hit on the microchannel plate collection system will also show an angular distribution, as Figure 8 shown; the anode plate at the back end of the microchannel plate collection system can achieve the resolution of the energy direction of the cold plasma in the horizontal direction based on the positions where the cold plasma finally hits on the microchannel plate collection system.

[0123] Based on the above, it can be seen that the energy spectrometer of the present invention can measure the lowest energy of 0.01 eV within the achievable preset bias voltage range, has good energy resolution, and can perform angular resolution measurement in the energy direction. It is applicable to the ionospheric plasma environment with low energy and high density, and can achieve a complete measurement of the energy magnitude and direction distribution of the background cold plasma in the ionosphere in the horizontal plane direction.

[0124] Those skilled in the art can understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

[0125] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. A spectrometer for measuring the energy distribution of cold plasma, characterized in that: The energy spectrometer comprises: A first grounded housing is provided with an entryway; A second grounded shell comprises a hemispherical structure shell, a first annular structure shell and a second annular structure shell, wherein the hemispherical surface of the hemispherical structure shell is provided with a first channel aperture, and the first annular structure shell is provided with a second channel aperture; A first bias electrode is located between the first circular ring structure shell and the second circular ring structure shell, and a first uniform electric field generated by the first bias electrode generates a first edge overflow field between the first circular ring structure shell and the top of the first grounded shell through the second channel aperture; A second bias electrode, comprising a hemispherical structure electrode, a pore is provided at the bottom center of the hemispherical structure electrode, a third channel aperture is provided on the hemispherical surface of the hemispherical structure electrode, a second uniform electric field generated by the second bias electrode generates a second edge overflow field between the hemispherical structure shell and the top of the first grounded shell through the first channel aperture, and the interior of the hemispherical structure electrode is a field-free drift region; An energy distribution determination system is used to determine the energy distribution information of the received cold plasma; wherein the energy of the cold plasma that can sequentially pass through the inlet channel, the first edge overflow field, the second edge overflow field, the second uniform electric field, the field-free drift region and the pore and enter the energy distribution determination system meets preset conditions.

2. The energy spectrometer according to claim 1, characterized in that: The inlet channel is used for cold plasmas of different energy levels to be injected into the spectrometer through the inlet channel; The first edge overflow field is used to cause the cold plasma passing through the inlet channel to undergo a first deflection so as to prevent the cold plasma that does not meet a preset energy range from entering the second edge overflow field; The second edge overflow field is used to cause the cold plasma entering the second edge overflow field to undergo a second deflection, so as to prevent the cold plasma that does not meet the preset energy range from entering the second uniform electric field through the first channel aperture.

3. The spectrometer according to claim 2, characterized in that: The diameter of the hemispherical structure electrode is smaller than the diameter of the hemispherical structure shell, and the hemispherical structure electrode generates the second uniform electric field between the hemispherical structure electrode and the hemispherical structure shell; the second uniform electric field and the field-free drift zone are used to make the cold plasma that meets the preset energy range drift linearly to the bottom of the hemispherical structure electrode through the third channel aperture, and expand the horizontal position offset of the cold plasma caused by the two deflections.

4. The spectrometer according to claim 1, characterized in that: The energy distribution determination system includes a microchannel plate collection system and an anode plate; The microchannel plate collection system is used to collect the cold plasma passing through the pores and accelerate the collected cold plasma to generate an electron cloud; The anode plate is used to count the electron cloud clusters and determine the energy direction of the cold plasma corresponding to the electron cloud clusters; The energy distribution information includes the energy direction and energy magnitude of the cold plasma.

5. The spectrometer according to claim 4, characterized in that: The energy spectrometer further comprises a first molybdenum mesh, the first molybdenum mesh being located between the inlet channel and the first channel aperture and being used for isolating the first edge overflow field and the second edge overflow field; Among them, the first molybdenum mesh is connected to the first grounded shell and the first circular ring structure shell to ensure that the potential of the first molybdenum mesh is consistent with that of the grounded shell, and the cold plasma enters the second edge overflow field from the first edge overflow field through the first molybdenum mesh.

6. The energy spectrometer according to claim 5, characterized in that: The energy spectrometer also includes a second molybdenum mesh, a third molybdenum mesh and a fourth molybdenum mesh; The second molybdenum mesh is located at the aperture of the third channel, and is used to ensure that the spherical gap electric field between the hemispherical structure electrode and the hemispherical structure shell is a uniform electric field, so as to obtain the second uniform electric field; The third molybdenum mesh is located at the pores, and is used to ensure that the field-free drift region inside the hemispherical structure electrode is not destroyed while ensuring that the cold plasma passes through; The fourth molybdenum mesh is located between the bottom of the hemispherical structure electrode and the microchannel plate collection system, and is used to isolate the voltage of the microchannel plate collection system.

7. The energy spectrometer according to claim 6, characterized in that: The transmittances of the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh and the fourth molybdenum mesh are all less than or equal to 0.1, and are used to weaken the ion flux of cold plasma.

8. The energy spectrometer according to claim 1, characterized in that: The double spherical structure formed by the hemispherical structure shell and the hemispherical structure electrode is used to converge cold plasma in the same direction in the horizontal direction.

9. The energy spectrometer according to any one of claims 1 to 8, characterized in that: The voltages of the first bias electrode and the second bias electrode are both set to a preset bias voltage; the range of the preset bias voltage is -5V~-2500V.

10. The energy spectrometer according to claim 9, characterized in that: The preset condition characterizes the energy size of the cold plasma as the target energy, and the target energy is determined according to the preset bias voltage; the energy spectrometer is used to measure the energy distribution of cold plasmas of different energy sizes by performing voltage scanning within the range of the preset bias voltage, wherein the range of the target energy is 0.01eV~5eV.

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