Energy dispersive spectrometer for measuring energy distribution of cold plasma

Abstract

The invention provides an energy disperse spectroscopy for measuring cold plasma energy distribution, which can be applied to the technical field of ionized layer plasma detection. According to the energy disperse spectroscopy, a first grounding shell is provided with an inlet channel; a first channel aperture is formed in the semispherical surface of the semispherical structure shell in the second grounding shell, and a second channel aperture is formed in the first circular ring structure shell; 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 grounding shell through the second channel aperture; a hole is formed in the center of the bottom of a hemispherical structure electrode in the second bias electrode, a third channel aperture is formed in the hemispherical surface, and 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 grounding shell through the first channel aperture; a field-free drift region is arranged in the semispherical structure electrode; the energy distribution determination system is used for determining energy distribution information of the received cold plasma.

Description

Technical Field

[0001] The invention relates to the technical field of ionospheric plasma detection, and in particular to an energy 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. The atmospheric molecules and atoms in this region are ionized by solar radiation and cosmic rays, generating free electrons and ions, thus forming a plasma state. Since the ionosphere of the Earth and other planets and satellites is closely related to daily life, it is very important to understand the energy and material activities in the ionosphere.

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

[0004] The 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 the detection of extremely low energy cold plasma in the ionosphere. Therefore, the complete detection of the energy distribution of cold plasma, the main component of the ionosphere, is a technical problem that needs to be solved in ionospheric detection. Summary of the invention

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

[0006] A first grounded housing is provided with an entryway;

[0007] The 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;

[0008] 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;

[0009] 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;

[0010] 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 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 pores and enter the above-mentioned energy distribution determination system meets the preset conditions.

[0011] According to the energy spectrometer for measuring the energy distribution of cold plasma provided by the present invention, the uniform electric field generated by the first bias electrode and the second bias electrode does not directly act on the path of the cold plasma, but acts on the path of the cold plasma injected into the energy spectrometer through the first edge overflow field and the second edge overflow field generated by the second channel aperture in the second grounded shell and the first channel aperture. Since the electric fields in the first edge overflow field and the second edge overflow field are very weak, the extremely low-energy cold plasma can be deflected so that the energy distribution determination system can collect the extremely low-energy cold plasma, so that the energy distribution of the extremely low-energy cold plasma can be determined based on the energy distribution determination system. Therefore, the energy spectrometer can be suitable for the extremely low-energy and high-density ionospheric cold plasma environment, and can achieve complete measurement of the energy magnitude and direction distribution of the cold plasma in the ionosphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 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:

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

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

[0015] Figure 3 A schematic diagram of the internal electric field area distribution of an energy spectrometer for measuring cold plasma energy distribution according to an embodiment of the present invention is shown.

[0016] Figure 4 A schematic diagram showing the distribution of molybdenum meshes in an energy spectrometer according to an embodiment of the present invention is shown.

[0017] Figure 5 A schematic diagram of the flight paths of cold plasmas with different energy levels inside an energy spectrometer is shown according to an embodiment of the present invention when a preset bias voltage is -5V.

[0018] Figure 6 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 is shown.

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

[0020] Figure 8 A schematic top view of the path of cold plasma according to an embodiment of the present invention is shown.

[0021] Fig. 9 A schematic diagram of an anode plate according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0022] 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.

[0023] 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.

[0024] 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.

[0025] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0026] In the process of realizing the present invention, it is found that there are many space in-situ detectors that can be used for ionosphere detection. Langmuir probes and retarding potential analyzers are the main means of detecting cold plasma in the ionosphere. They collect a large number of charged particles incident on cold plasma through metal collecting electrodes and output current signals, which can be called "integral type" detection instruments. However, these detectors can only measure the isotropy of the entire cold plasma block in a region, and cannot know the changes in the local anisotropy of cold plasma, such as the microcurrent of small-scale directional movement of ions, local heating of cold plasma, local instability of plasma 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 angle resolution, so that it can analyze the particle incident angle while performing energy analysis. It is the most commonly used instrument for measuring the size and direction distribution of ion energy. However, the cold plasma in the ionosphere has the characteristics of extremely low energy and high density. The limitation of the minimum voltage that the satellite power supply can provide is not suitable for detecting extremely low energy cold plasma in the ionosphere.

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

[0029] Figure 1 A diagram showing an application scenario of an energy spectrometer for measuring energy distribution of cold plasma according to an embodiment of the present invention is shown.

[0030] like Figure 1 As shown, the application scenario of this embodiment may include the energy spectrometer 101 for measuring the energy distribution of cold plasma and the on-orbit satellite 102. The energy spectrometer 101 for measuring the energy distribution of cold plasma and the on-orbit satellite 102 are located in a 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 a carrier, the spectrometer 101 is a payload, and the spectrometer 101 is used to measure the energy distribution of cold plasma in the ionosphere near the on-orbit satellite 102. The plasma environment may 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 on-orbit satellite 102 and the spin mode of the on-orbit satellite 102, that is, the spectrometer 101 moves along the orbital motion direction as the on-orbit satellite 102 rotates along the orbital axis while moving along the orbital motion direction of the on-orbit satellite 102, it is possible to achieve complete imaging of the energy size and direction of the cold plasma in the entire ionosphere space near the on-orbit satellite 102, thereby achieving the purpose of small-scale precise measurement of the ionospheric background cold plasma, and also helps to understand the local change mechanism of the ionosphere, such as plasma internal microcurrents, cold plasma heating, plasma local instability, etc., which plays an important role in order to make a deeper study on the behavior state of the cold plasma in the ionosphere.

[0033] The following will be based on Figure 1 The scene described by Figure 2~Figure 9 The energy spectrometer for measuring the energy distribution of cold plasma according to an embodiment of the present invention is described in detail.

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

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

[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 energy spectrometer can be displayed, that is, Figure 2 shown.

[0037] like Figure 2 As shown, the outside of the energy spectrometer is a first grounded shell, that is, the first grounded shell is a cylindrical structure, and an entrance channel is arranged on the first grounded shell, wherein the first grounded shell is mainly used to provide support and isolate external interference; the entrance channel is a circle of channels on the side of the first grounded shell, which is used for the cold plasma within 360° of the same plane to be injected into the energy spectrometer.

[0038] According to an embodiment of the present invention, the energy spectrometer for measuring cold plasma energy distribution also includes a second grounded shell, which may include three parts: a hemispherical structure shell, a first annular structure shell and a second annular structure shell.

[0039] According to an embodiment of the present invention, the entrance channel is arranged on the side of the first grounded shell corresponding to between the top of the first grounded shell and the first annular structure shell, and the entrance channel is an annular channel arranged on the side of the first grounded shell.

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

[0041] The thickness of the first grounded shell and the second grounded shell can be set between 1 mm and 1.5 mm to ensure that the grounded shell has a certain thickness and is light enough; the first grounded shell and the second grounded shell both maintain the ground potential or the potential of the satellite payload surface.

[0042] The thickness of the hemispherical structure shell in the second grounded shell may be, for example, 1 mm, and the inner and outer radii of the hemispherical structure shell may be 15 mm and 16 mm.

[0043] According to an embodiment of the present invention, the energy spectrometer for measuring the energy distribution of cold plasma further comprises 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 shell and the second circular ring structure shell, wherein the first bias electrode can be set to a circular ring structure with an inner circle radius of 20 mm, an outer circle 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 A schematic diagram of the internal electric field area distribution of an energy spectrometer for measuring cold plasma energy distribution 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, the first bias electrode generates a first uniform electric field between the first annular structure shell and the second annular structure shell. Figure 3 The first uniform electric field is generated in the region 310 shown in FIG. 3 . The first uniform electric field generated by the first bias electrode generates a first edge overflow field between the first annular structure shell and the top of the first grounded shell through the second channel aperture. Figure 3 A first edge overflow field is generated in the region 320 shown in FIG.

[0046] 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 may be, for example, 1 mm thick, gradually increasing from 1 mm in width on the lower surface to 2 mm in width on the upper surface.

[0047] According to an embodiment of the present invention, the second bias electrode may include a hemispherical structure electrode portion, wherein the hemispherical structure electrode may be configured 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 shell, that is, in the internal structure of the spectrometer, the hemispherical structure electrode is located directly below the hemispherical structure shell; a pore is arranged at the bottom center position of the hemispherical structure electrode, and a third channel aperture is arranged 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, the second bias electrode generates a second uniform electric field between the hemispherical structure electrode and the hemispherical structure shell. Figure 3 The 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, that is, Figure 3 The second edge overflow field is generated in the region 330 shown in FIG. 1 , and the interior of the hemispherical structure electrode is a field-free drift region, that is, Figure 3 The region 350 shown in FIG. 3 is a field-free drift region.

[0050] Based on the above content, it can be known that the second grounded shell inside the spectrometer can be used to adjust the electric field configuration inside the spectrometer, that is, based on the second grounded shell, the inside of 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.

[0051] The first grounding shell, the second grounding shell, the first bias electrode and the second bias electrode can all be made of aluminum alloy or titanium alloy, that is, materials with good conductivity and low density can be selected.

[0052] According to an embodiment of the present invention, the energy spectrometer for measuring the energy distribution of cold plasma further comprises an energy distribution determination system, such as Figure 2 As shown in the figure, the energy distribution determination system is located directly below the second bias electrode to determine the energy distribution information of the received cold plasma; wherein 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 zone and the pores and enter the energy distribution determination system meets the preset conditions.

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

[0054] like Figure 2 As shown in , the centers of the first grounded shell, the second grounded shell, the first bias electrode, the second bias electrode and the energy distribution determination system in the energy 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 field generated by the first bias electrode and the second bias electrode does not directly act on the path of the cold plasma, but acts on the path of the cold plasma injected into the energy spectrometer through the first edge overflow field and the second edge overflow field generated by the second channel aperture in the second grounded shell and the first channel aperture. Since the electric fields in the first edge overflow field and the second edge overflow field are very weak, the extremely low energy cold plasma can be deflected so that the energy distribution determination system can collect the extremely low energy cold plasma, so that the energy distribution of the extremely low energy cold plasma can be determined based on the energy distribution determination system. Therefore, the energy spectrometer can be suitable for the extremely low energy and high density ionospheric cold plasma environment, and can achieve complete measurement of the energy magnitude and direction distribution of the cold plasma in the ionosphere.

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

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

[0058] According to an embodiment of the present invention, Figure 2 As shown in , the cold plasma injected into the energy spectrometer needs to be able to pass through the first channel aperture, the third channel aperture and the pore in sequence before it can be collected by the energy distribution determination system. The microchannel plate collection system is used to collect the cold plasma passing through the pore 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 electron clouds, the anode plate counts the generated electron clouds and determines the angle of each electron cloud to determine the energy direction of the corresponding cold plasma, wherein the energy direction can characterize the direction in which the cold plasma enters the energy spectrometer.

[0060] The incident surface of the microchannel plate collection system can maintain a bias voltage of more than -2000V to accelerate the cold plasma to reach the energy of generating electron clouds. 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 cold plasma that sequentially passes through the first channel aperture, the third channel aperture and the aperture and enters the energy distribution determination system, the energy distribution determination system can achieve angle-resolved measurement of the energy direction of the cold plasma.

[0062] According to an embodiment of the present invention, the energy spectrometer also includes a first molybdenum mesh, which is located between the entrance 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 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.

[0063] According to an embodiment of the present invention, 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 third channel aperture, 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 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 zone inside the hemispherical structure electrode is not destroyed while ensuring that 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 spectrometer further includes a first molybdenum mesh, a second molybdenum mesh, a third molybdenum mesh and a fourth molybdenum mesh.

[0065] Figure 4 A schematic diagram showing the distribution of molybdenum meshes in an 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 shell and the first annular structure shell, such as Figure 4 The first molybdenum mesh is located in the middle; the first molybdenum mesh isolates the first edge overflow field and the second edge overflow field, that is, Figure 3 As shown in FIG. 3 , the first molybdenum mesh isolates region 330 and region 320 , so that the cold plasma needs to pass through the first molybdenum mesh from the first edge overflow field into the second edge overflow field.

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

[0068] According to an embodiment of the present invention, the third molybdenum mesh is located at the pores, such as Figure 4 The position of the third molybdenum mesh in the middle is to ensure that the cold plasma can pass through without destroying the field-free drift zone 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. Figure 4 The fourth molybdenum mesh is located in the middle; 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 improve the accuracy of the subsequently determined energy 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 spectrometer are located in multiple areas of the flight path of the cold plasma in the spectrometer. While allowing the cold plasma to pass smoothly, they also act as electrostatic shielding of the conductor 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 shell is a uniform electric field, ensure that the field-free drift zone inside the hemispherical structure electrode is not destroyed, 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 are all less than or equal to 0.1, which are used to weaken the ion flux of cold plasma.

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

[0073] Among them, ion flux refers to the number of ions passing through an area per square centimeter per unit time; the first molybdenum mesh, the second molybdenum mesh, the third molybdenum mesh and the fourth molybdenum mesh can all be selected from 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 are all 0.1, since the cold plasma needs to pass through four layers of molybdenum mesh from incident to collected by the energy distribution determination system, the flux of the cold plasma can be reduced by 10,000 times, thereby meeting the counting range of the energy distribution determination system.

[0075] According to an embodiment of the present invention, a first molybdenum mesh, a second molybdenum mesh, a third molybdenum mesh and a fourth molybdenum mesh with low transmittance are used to weaken the flux of cold plasma, so that the weakened ion flux can meet the counting range of the energy distribution determination system, avoid exceeding the counting upper limit of the energy distribution system to cause overload, and affect the accuracy of the energy distribution system counting and energy distribution information determination.

[0076] According to an embodiment of the present invention, an entrance channel is used to inject cold plasma of different energy sizes into the energy spectrometer; the first edge overflow field is used to cause the cold plasma passing through the entrance channel to undergo a first deflection to prevent 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 cause the cold plasma entering the second edge overflow field to undergo a second deflection 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.

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

[0078] According to an embodiment of the present invention, after cold plasmas of different energy sizes are injected into the spectrometer through the entrance channel from different incident directions, the cold plasma will undergo a first deflection in the first edge overflow field and a second bias in the second edge overflow field, so that the cold plasma meeting the preset energy range enters the second uniform electric field through the first channel aperture, wherein the preset energy range is related to the voltage applied to the first bias electrode and the second bias electrode.

[0079] According to an embodiment of the present invention, deflecting the cold plasma twice based on the first edge overflow field and the second edge overflow field can further block the cold plasma that does not meet the preset energy range, thereby avoiding missing the blocking of the 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 shell, and the hemispherical structure electrode generates a 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.

[0081] According to an embodiment of the present invention, the cold plasma entering the second uniform electric field will pass through the third channel aperture to the bottom of the hemispherical structure electrode. The cold plasma will deviate linearly in the second uniform electric field and the field-free drift region to expand the horizontal position bias caused by the double deflection of the cold plasma by the first edge overflow field and the second edge overflow field, wherein the horizontal position refers to the radial direction of the spectrometer.

[0082] Among them, cold plasma that meets the preset energy range will drift in a straight line to the bottom of the hemispherical structure electrode, but only cold plasma with a specific energy size in 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 drifts linearly in the second uniform electric field and field-free offset region to further expand the horizontal position offset caused 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, a double spherical structure composed of a hemispherical structure shell and a hemispherical structure electrode is used to converge cold plasma in the same direction in a horizontal direction.

[0085] According to the embodiment of the present invention, due to the double spherical structure formed by the hemispherical structure shell and the hemispherical structure electrode, cold plasma in the same direction can be converged in the horizontal direction, which is conducive to 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 preset bias voltage ranges from -5V to -2500V.

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

[0088] According to an embodiment of the present invention, the preset conditions can characterize 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 target energy range is 0.01eV~5eV.

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

[0090] According to an embodiment of the present invention, the energy of the cold plasma collected by the energy distribution determination system in the energy spectrometer of the present invention is linearly related to the bias voltages of the first bias electrode and the second bias electrode. The linear relationship is shown in the following formula (1).

[0091] (1);

[0092] in, It can be expressed as the energy of cold plasma, can be expressed as the charge number, It can be expressed as the absolute value of the bias voltage of the first bias electrode and the second bias electrode, .

[0093] Based on the above formula (1), on the basis of the negative bias voltage of -5V~-2500V that can be achieved on the satellite, the energy spectrometer of the present invention can measure cold plasma with energy of 0.01eV~5eV, where 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, the energy distribution can be determined by the above formula (1) to determine the energy of the cold plasma collected by the system at this moment.

[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 shell and the hemispherical structure electrode can be adjusted according to the path of the cold plasma inside the energy spectrometer to obtain Figure 4 The structure shown ensures that cold plasma with target energy can pass through the pores at the bottom of the hemispherical structure electrode by two deflections.

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

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

[0098] like Figure 5 As shown, taking incident cold plasmas of 1eV, 0.001eV, 0.02eV, 0.0103eV, 0.097eV, and 0.01eV as examples, when the preset bias voltage of the first bias electrode and the second bias electrode is -5V, the flight paths of cold plasmas of various energy levels inside the energy spectrometer. Figure 5 The voltage of each electrode has been marked, and the parts without electrodes marked are all grounded shells.

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

[0100] exist Figure 5 In the process, cold plasmas of various energy sizes are affected by the electric field and undergo a first deflection in the first edge overflow field, thereby blocking cold plasmas that do not meet the preset energy range from entering the second edge overflow field. That is, since the energy gap between cold plasmas of 1eV and 0.001eV and the target energy of 0.01eV is 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] The preset energy range may represent an energy range that is not much different from the target energy, such as Figure 5 The cold plasmas with energy levels of 1 eV and 0.001 eV shown in the figure do not meet the preset energy range, while the cold plasmas with energy levels of 0.02 eV, 0.0103 eV, 0.097 eV, and 0.01 eV meet the preset energy range.

[0102] exist Figure 5 In the process, the cold plasma entering the second edge overflow field will undergo a second deflection to further block the cold plasma that fails to be blocked and does not meet the preset energy range, so that only the cold plasma that meets the preset energy range enters 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 be different; the greater the energy of the cold plasma, the smaller the degree of deflection, such as Figure 5 As shown in , the cold plasma with an energy of 1 eV has a smaller deflection degree and thus hits the first grounded shell after deflection, and the cold plasma with an energy of 0.001 eV has a smaller deflection degree and thus hits the first circular ring structure shell after deflection.

[0104] like Figure 5 As shown in, the cold plasma with energy sizes of 0.02eV, 0.0103eV, 0.097eV, and 0.01eV entering the second uniform electric field drifts linearly in the second uniform electric field and the field-free drift zone, and the cold plasma with energy sizes of 0.02eV, 0.0103eV, and 0.097eV will be linearly offset to the bottom of the hemispherical structure electrode, and only the cold plasma with energy size of 0.01eV can pass through the pores to be collected by the energy distribution determination system.

[0105] Figure 6 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 is shown.

[0106] like Figure 6 As 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 loops shown in are equipotential lines around the flight path of the cold plasma.

[0107] 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 an achievable preset bias voltage range to deflect extremely low energy cold plasma, thereby enabling the measurement of extremely low energy cold plasma.

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

[0109] like Figure 7 As shown, taking the incident cold plasma of 5eV, 0.1eV, 0.01eV, 2.5eV, 1.03eV, 0.97eV, and 1eV as examples, when the preset bias voltage of the first bias electrode and the second bias electrode is -500V, the flight paths of the cold plasmas of various energy levels inside the energy spectrometer. Figure 7 The voltage of each electrode has been marked, and the parts without electrodes marked are all grounded shells.

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

[0111] exist Figure 7 In the process, cold plasmas of various energy sizes are affected by the electric field and undergo a first deflection in the first edge overflow field, thereby blocking cold plasmas that do not meet the preset energy range from entering the second edge overflow field. That is, since the energy gap between cold plasmas of 5eV, 0.1eV and 0.01eV and the target energy of 1eV is 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.

[0112] Among them, Figure 5 The cold plasmas with energy levels of 5 eV, 0.1 eV and 0.01 eV shown in the figure do not meet the preset energy range, while the cold plasmas with energy levels of 2.5 eV, 1.03 eV, 0.97 eV and 1 eV meet the preset energy range.

[0113] exist Figure 7 In the process, the cold plasma entering the second edge overflow field will undergo a second deflection to further block the cold plasma that fails to be blocked and does not meet the preset energy range, so that only the cold plasma that meets the preset energy range enters the second uniform electric field.

[0114] Among them, Figure 5 As shown in , the cold plasma with an energy of 5 eV has a smaller deflection degree and thus hits the first grounded shell after deflection, while the cold plasma with an energy of 0.1 eV and 0.01 eV has a smaller deflection degree and thus hits the first circular ring structure shell after deflection.

[0115] like Figure 7 As shown in, 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 zone, and the cold plasma with energy sizes of 2.5eV, 1.03eV, and 0.97eV will be linearly offset to the bottom of the hemispherical structure electrode, and only the cold plasma with energy size of 1eV can pass through the pores to be collected by the energy distribution determination system.

[0116] exist Figure 5 and Figure 7 In the example, after changing the preset bias voltage to -500V, Figure 7 The cold plasma path with 1eV energy is Figure 5The paths of the cold plasma with an energy of 0.01eV overlap, but the paths between the fourth molybdenum mesh and the energy distribution determination system do not overlap. 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] by Figure 5 and Figure 7 For example, cold plasma that does not meet the preset energy range cannot enter the second uniform electric field because of the two deflections in the first edge overflow field and the second edge field. The actual energy of the ions collected by the energy distribution determination system is between 0.097eV~0.013eV and 0.97eV~1.03eV, respectively. That is, the energy resolution of the energy spectrometer of the present invention can reach within 6%, so that it can have better energy resolution performance at extremely low energy; and the design of other geometric structures inside the energy spectrometer makes the electrodes in other regions except the deflection region directly act on the cold plasma as a uniform field, which will not affect the path deflection of the extremely low energy cold plasma, so it can achieve Figure 5 and Figure 7 energy resolution level.

[0118] Figure 8 A schematic top view of the path of cold plasma according to an embodiment of the present invention is shown.

[0119] like Figure 8 As shown, the flight paths of cold plasmas of the same energy at different incident angles are viewed from above inside the energy spectrometer, wherein only a portion of the cold plasma incident on a certain area can be collected by the microchannel plate collection system and converged to a point in the microchannel plate collection system, and the cold plasma incident on the certain area can be regarded as having the same incident angle; the microchannel plate collection system can also be called a microchannel plate.

[0120] Fig. 9 A schematic diagram of an anode plate according to an embodiment of the present invention is shown.

[0121] like Fig. 9 As shown, the anode plate can be a discrete anode plate, which includes a plurality of anode blocks, each of which corresponds to an angle range, and the anode plate has an angle resolution function to determine the energy direction of the cold plasma. The PCB insulating bracket is used to provide a 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 the cold plasma with different incident angles finally hits the microchannel plate collection system will also present an angle distribution, such as Figure 8 As shown; the anode plate at the rear end of the microchannel plate collection system can resolve the energy direction of the cold plasma in the horizontal direction based on the position where the cold plasma finally hits the microchannel plate collection system.

[0123] Based on the above content, it can be known that the energy spectrometer of the present invention can measure the minimum energy of 0.01eV within the achievable preset bias voltage range, has good energy resolution, and can perform angular resolution measurement of the energy direction. It is suitable for low-energy and high-density ionospheric plasma environments, and can achieve complete measurement of the energy size and direction distribution of the background cold plasma in the ionosphere in the horizontal plane.

[0124] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may 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 may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

[0125] 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 each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. 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

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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