Electron detectors and charged particle detectors

Abstract

To provide an electron detector and a charged particle detector that can improve the quality of electrical signals. [Solution] The electron detector 5 comprises an electron detection unit 53 including a first electrode 52, a resin sheet 59 positioned on one side in the Z direction relative to the first electrode 52, a second electrode 54 facing the first electrode 52 via the resin sheet 59, an insulating substrate 61 positioned on one side in the Z direction relative to the second electrode 54 and supporting the electron detection unit 53, the resin sheet 59 and the second electrode 54, an output unit 55 positioned on one side in the Z direction relative to the insulating substrate 61, electrically connected to the second electrode 54 and outputting an electrical signal, and a support unit 62 supporting the output unit 55 such that the output unit 55 and the second electrode 54 face each other via the insulating substrate 61 and a space SP1 is formed between the output unit 55 and the insulating substrate 61.

Description

Technical Field

[0001] The present invention relates to an electron detector and a charged particle detector.

Background Art

[0002] As a charged particle detector applicable to a mass spectrometry device, etc., Patent Document 1 describes an ion detector including a microchannel plate (hereinafter referred to as "MCP") that emits electrons upon incidence of ions, an anode electrode that detects electrons emitted from the MCP, a coaxial cable including an internal conductor electrically connected to the anode electrode, and a ground electrode electrically connected to an outer conductor of the coaxial cable. In the ion detector described in Patent Document 1, the anode electrode is configured by arranging a dielectric member between the collector electrode and the conductive plate. As a result, the collector electrode and the conductive plate function as a capacitor, and the DC component is removed from the electrical signal output via the coaxial cable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ion detector described in Patent Document 1, since the conductive plate included in the anode electrode serving as the electron detection unit and the ground electrode face each other, a parasitic capacitance occurs between the anode electrode and the ground electrode, and as a result, ringing may occur in the electrical signal output via the coaxial cable. When the ion detector is applied to a mass spectrometry device, if ringing occurs in the electrical signal output from the ion detector, the accuracy of mass spectrometry may decrease.

[0005] The present invention aims to provide an electron detector and a charged particle detector that can improve the quality of electrical signals. [Means for solving the problem]

[0006] The electron detector of the present invention is an electron detector comprising: [1] an electron detection unit including a first electrode for detecting incident electrons; a resin sheet disposed on one side in a first direction with respect to the first electrode; a second electrode disposed on the one side in a first direction with respect to the resin sheet and facing the first electrode via the resin sheet; an insulating substrate disposed on the one side in a first direction with respect to the second electrode and supporting the electron detection unit, the resin sheet and the second electrode; an output unit disposed on the one side in a first direction with respect to the insulating substrate, electrically connected to the second electrode and outputting the electrical signal; and a support unit that supports the output unit such that the output unit and the second electrode face each other via the insulating substrate and a space is formed between the output unit and the insulating substrate.

[0007] In the electron detector described in [1] above, the first and second electrodes, which face each other via a resin sheet, function as a capacitor that removes the DC component from the electrical signal detected in the electron detection unit. As a result, the electrical signal from which the DC component has been removed is output from the output unit. Furthermore, a resin sheet is used for the capacitor, and the electron detection unit, the resin sheet, and the second electrode are supported by an insulating substrate. This ensures sufficient voltage resistance for the capacitor and sufficient mechanical strength for the electron detector. In addition, the output unit is supported by a support unit such that a space is formed between the output unit and the insulating substrate. This reduces the parasitic capacitance generated between the output unit and the second electrode, and suppresses ringing in the electrical signal caused by parasitic capacitance. As a result, the quality of the electrical signal can be improved with the electron detector described above.

[0008] The electron detector of the present invention may also be [2] "the electron detector according to [1] above, wherein the width of the space in the first direction is greater than 1 / 3 times the thickness of the insulating substrate." According to the electron detector according to [2], the parasitic capacitance generated between the output unit and the second electrode can be sufficiently reduced.

[0009] The electron detector of the present invention may also be [3] "a charged particle detector according to [1] or [2] above, wherein the support portion is fixed to the insulating substrate." According to the electron detector described in [3], the output portion can be stably supported at a desired position relative to the insulating substrate.

[0010] The electron detector of the present invention may also be [4] "an electron detector according to any one of [1] to [3] above, further comprising: a third electrode disposed on the other side of the resin sheet in the first direction and spaced apart from the first electrode in a second direction intersecting the first direction; and a fourth electrode disposed on the one side of the resin sheet in the first direction and spaced apart from the second electrode in a second direction and facing the third electrode via the resin sheet, wherein the output unit includes an internal conductor electrically connected to one of the second electrode and the fourth electrode; and an external conductor surrounding the internal conductor in a state of being electrically insulated from the internal conductor and electrically connected to the other electrode of the second electrode and the fourth electrode." According to the electron detector described in [4], just as the first and second electrodes facing each other via the resin sheet function as capacitors, the third and fourth electrodes facing each other via the resin sheet also function as capacitors. One of these capacitors functions as a capacitor that removes the DC component from the electrical signal detected by the electron detection unit. As a result, the electrical signal from which the DC component has been removed is output from the internal conductor of the output section via the second or fourth electrode. Meanwhile, the other capacitor among these capacitors functions as a return capacitor placed on the return path through which the return current from the external conductor flows. This suppresses the degradation of the electrical signal waveform due to ringing and other factors.

[0011] The electron detector of the present invention may also be [5] "the electron detector according to [4] above, further comprising a spring connector, wherein the insulating substrate includes wiring electrically connected to the second electrode or the fourth electrode, and the spring connector is disposed between the wiring and the internal conductor or the external conductor." According to the electron detector according to [5], even if a space is formed between the output unit and the insulating substrate, electrical connection between the wiring and the internal conductor or the external conductor can be reliably achieved.

[0012] The electron detector of the present invention may also be [6] "the electron detector according to [4] above, further comprising a spring connector, wherein the insulating substrate includes a first wiring electrically connected to the second electrode or the fourth electrode, the support portion includes a second wiring electrically connected to the internal conductor or the external conductor, and the spring connector is disposed between the first wiring and the second wiring." According to the electron detector according to [6], even if a space is formed between the output portion and the insulating substrate, electrical connection between the first wiring and the second wiring can be reliably achieved.

[0013] The electron detector of the present invention may also be [7] "an electron detector according to any one of [4] to [6] above, further comprising a resistor electrically connected between the other electrode of the second and fourth electrodes and the outer conductor." According to the electron detector described in [7], the resistor absorbs the high-frequency components of the electrical signal, thereby more reliably suppressing ringing that occurs in the electrical signal.

[0014] The electron detector of the present invention may also be [8] "the electron detection unit further includes an avalanche diode electrically connected to the first electrode, and the avalanche diode detects the electrons, as described in any one of [1] to [7] above." According to the electron detector described in [8], electrons can be detected with high sensitivity by the avalanche effect of the avalanche diode.

[0015] The electron detector of the present invention may also be [9] "an electron detector according to any one of [1] to [7] above, wherein the first electrode detects the electrons." According to the electron detector described in [9], the first electrode serves as both an electrode for electron detection and an electrode for a coupling capacitor, thus simplifying the configuration of the electron detection unit.

[0016] The electron detector of the present invention may also be

[10] "an electron detector according to any one of [1] to

[11] above, further comprising an insulating layer that covers the second electrode on one side in the first direction relative to the resin sheet and covers the first electrode on the other side in the first direction relative to the resin sheet." According to the electron detector according to

[10] , deterioration of the first electrode and the second electrode can be suppressed.

[0017] The charged particle detector of the present invention may also be

[11] "a charged particle detector comprising an electron detector according to any one of [1] to

[10] above, and an electron emission unit that emits electrons upon the incidence of charged particles." According to the charged particle detector described in

[11] , the quality of the electrical signal can be improved in the electron detector.

[0018] The charged particle detector of the present invention may also be the charged particle detector described in

[11] above, wherein the electron emission unit includes a microchannel plate. According to the charged particle detector described in

[12] , the electrons emitted from the electron emission unit are amplified as secondary electrons, thereby increasing the electrical signal output from the electron detector. Furthermore, emission of secondary electrons with a high amplification factor can be achieved.

[0019] The charged particle detector of the present invention may also be the charged particle detector described in

[11] above, wherein the electron emission unit includes a plurality of dynodes. According to the charged particle detector described in

[13] , the electrons emitted from the electron emission unit are amplified as secondary electrons, so the electrical signal output from the electron detector can be made larger. Furthermore, emission of secondary electrons with a high amplification factor can be achieved. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide an electron detector and a charged particle detector that can improve the quality of electrical signals. [Brief explanation of the drawing]

[0021] [Figure 1] This is a diagram showing the circuit configuration of a charged particle detector according to an embodiment. [Figure 2] This is a cross-sectional view of the electron detector shown in FIG. 1. [Figure 3] This is a front view of the electron detector shown in FIG. 1. [Figure 4] This is a rear view of the electron detector shown in FIG. 1. [Figure 5] This is a cross-sectional view of the electron detector of the first modification. [Figure 6] This is a graph showing an example of the behavior of an electrical signal output from the electron detector shown in FIG. 5. <00,00095>This is a cross-sectional view of the electron detector of the second modification. [Figure 8] This is a cross-sectional view of the electron detector of the third modification. [Figure 9] This is a cross-sectional view of the electron detector of the fourth modification. [Figure 10] This is a cross-sectional view of the charged particle detector of the modification. [Embodiments of the Invention]

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. [Configuration of Charged Particle Detector]

[0023] The electron detector of the present invention outputs incident electrons as an electron signal. The electron detector of the present invention can be applied to, for example, charged particle detectors, photomultiplier tubes, or hybrid photodetectors. In this embodiment, an example in which the electron detector is applied to a charged particle detector will be described. As shown in Figure 1, the charged particle detector 1 comprises an electron emission unit 2, an accelerating electrode 3, a focusing electrode 4, and an electron detector 5. In the charged particle detector 1, the electron emission unit 2, the accelerating electrode 3, the focusing electrode 4, and the electron detection unit 53 of the electron detector 5 are arranged in this order. The charged particle detector 1 is, for example, an ion detector that detects bipolar ions. The charged particle detector 1 can be applied to, for example, a mass spectrometer. The charged particle detector 1 may also detect charged particles other than ions (for example, electrons, etc.).

[0024] The electron emission unit 2 emits electrons upon incidence of ion IN. The polarity of ion IN may be negative or positive. The electron emission unit 2 includes a microchannel plate (hereinafter referred to as "MCP") 21. The MCP 21 is an electron multiplier element that emits electrons in response to incidence of ion IN. The MCP 21 has an input surface 21a and an output surface 21b. The sides of the MCP 21 are surrounded by an insulating ring made of an insulating material. When ion IN is incident on the input surface 21a of the MCP 21, it generates electrons in response to the incidence of ion IN, multiplies those electrons, and emits them from the output surface 21b. In other words, the MCP 21 also functions as an electron multiplier unit. The MCP 21 has a plurality of through holes (channels) formed along the thickness direction (the direction in which the input surface 21a and the output surface 21b face each other). Electrodes are formed on the outer edge of the input surface 21a and the outer edge of the output surface 21b. Furthermore, the electron emission unit 2 may independently include an electron emission unit that emits electrons upon incidence of ion IN, and an electron multiplication unit that emits electrons multiplied by multiples. For example, the electron emission unit 2 may include an ion-electron conversion unit provided upstream of the MCP21 as the electron emission unit, and the MCP21 as the electron multiplication unit.

[0025] The accelerating electrode 3 accelerates electrons emitted from the output surface 21b of the MCP 21. The focusing electrode 4 focuses the electrons accelerated by the accelerating electrode 3 onto the electron detection unit 53 of the electron detector 5.

[0026] The electron detector 5 outputs electrons emitted from the MCP 21 as an electrical signal. The electron detector 5 includes an electron detection unit 53 containing an avalanche diode (hereinafter referred to as "AD") 51 and a first electrode 52, a second electrode 54, an output unit 55, a signal output terminal 56, a third electrode 57, and a fourth electrode 58.

[0027] AD51 receives electrons focused by the focus electrode 4 and outputs them as an electrical signal. The anode electrode 511 of AD51 faces the focus electrode 4. That is, electrons focused by the focus electrode 4 are incident on the anode electrode 511.

[0028] The first electrode 52 is electrically connected to the cathode electrode 512 of AD51. The first electrode 52 and the second electrode 54 constitute a signal capacitor C1. The signal capacitor C1 functions as a coupling capacitor that removes the DC component from the electrical signal output from AD51.

[0029] The output section 55 is electrically connected to the second electrode 54 and outputs an electrical signal toward the signal output terminal 56. The output section 55 includes an inner conductor 551 and an outer conductor 552. The inner conductor 551 is electrically connected to the second electrode 54. The outer conductor 552 surrounds the inner conductor 551. There may be an air gap between the inner conductor 551 and the outer conductor 552, or an insulating member may be placed between them. The outer conductor 552 is connected to a reference potential GND. The output section 55 is, for example, an SMA connector. In this case, the inner conductor 551 is a signal line that transmits an electrical signal, and the outer conductor 552 is an outer conductor that covers the signal line.

[0030] The third electrode 57 is electrically connected to the anode electrode 511 of AD51. The fourth electrode 58 is electrically connected to the reference potential GND and the outer conductor 552. The third electrode 57 and the fourth electrode 58 are arranged on a return path formed from the outer conductor 552 to the anode electrode 511, and constitute a return capacitor C2. The arrangement of the return capacitor C2 suppresses the degradation of the electrical signal waveform due to ringing, etc. Ringing is a high-frequency component superimposed on an electrical signal when the magnitude of the electrical signal changes, such as during the rising or falling edge of the electrical signal.

[0031] Parasitic capacitance Cp may occur between the second electrode 54 and the outer conductor 552. Parasitic capacitance Cp is a parasitic component that arises when the second electrode 54 and the outer conductor 552 face each other. Parasitic capacitance Cp may cause ringing in the electrical signal output from the signal output terminal 56. If, for example, a mass spectrometer is connected downstream of the electron detector 5, ringing in the electrical signal may prevent the mass spectrometer from accurately reading the magnitude of the electrical signal, potentially affecting the accuracy of the mass spectrometry. Therefore, it is extremely important to minimize parasitic capacitance Cp as much as possible to suppress the effects of ringing.

[0032] The input surface 21a of the MCP21 is electrically connected to the power supply 71 and set to a potential Va (e.g., +10kV or -10kV). A potential difference Vb (e.g., 0V to 1kV) is supplied between the input surface 21a and the output surface 21b by the power supply 72. One end of resistor Ra is electrically connected to the node between the cathode electrode 512 and the first electrode 52. A potential difference Vc (e.g., 0V to 6kV) is supplied between the output surface 21b and the other end of resistor Ra by the power supply 73. The potential difference (voltage) Vc is divided by resistor Rb (e.g., 40MΩ), resistor Rc (e.g., 20MΩ), and Zener diode 74. The Zener diode 74 ensures a potential difference of 300V between resistor Rc and resistor Ra. The accelerating electrode 3 is electrically connected to the node located between resistor Ra and resistor Rb. The focus electrode 4 is set to the same potential as the output surface 21b. A resistor Rd is electrically connected between the node between resistor Rc and Zener diode 74 and the anode electrode 511.

[0033] When measuring negative ions IN, a potential Va of, for example, +10kV is applied. In this case, if the potential difference Vb is +1kV and the potential difference Vc is +6kV, the potential at the other end of resistor Ra will be +17kV. When measuring positive ions IN, a potential Va of, for example, -10kV is applied. In this case, if the potential difference Vb is +1kV and the potential difference Vc is +6kV, the potential at the other end of resistor Ra will be -3kV. In both the measurement of negative and positive ions IN, the potential increases as you move from the input surface 21a of MCP21 toward the anode electrode 511 of AD51. Furthermore, the potential applied to the cathode electrode 512 of AD51 is greater than the potential applied to the anode electrode 511. Therefore, a reverse bias voltage is applied between the anode electrode 511 and the cathode electrode 512 of AD51, causing AD51 to operate in a floating state. [Electron detector configuration]

[0034] As shown in Figures 2, 3, and 4, the electron detector 5 further comprises a resin sheet 59, an insulating substrate 61, a support portion 62, and an insulating layer 63. Hereinafter, the thickness direction of the insulating substrate 61 will be referred to as the Z direction (first direction), one direction perpendicular to the Z direction will be referred to as the X direction (second direction), and the direction perpendicular to both the Z and X directions will be referred to as the Y direction. In the electron detector 5, AD 51, the first electrode 52, the resin sheet 59, the second electrode 54, the insulating substrate 61, and the output unit 55 are arranged in this order in the Z direction. In the following description, "arranged on one side" means that each component is arranged on the opposite side of AD 51 (the output unit 55 side) from adjacent components on the AD 51 side. "Arranged on the other side" means that each component is arranged on the opposite side of the output unit 55 (the AD 51 side) from adjacent components on the output unit 55 side.

[0035] AD51 is positioned, for example, at the location where electrons emitted from MCP21 arrive. The first electrode 52 is positioned on the opposite side of AD51 from MCP21 and is electrically connected to AD51. In the electron detector 5, the first electrode 52 is in contact with the cathode electrode 512 of AD51.

[0036] The resin sheet 59 is positioned on one side of the first electrode 52 in the Z direction. The resin sheet 59 is in contact with the first electrode 52. The material of the resin sheet 59 is a resin such as liquid crystal polymer (LCP), polyester film, polyimide, or polyamide. The second electrode 54 is positioned on one side of the resin sheet 59 in the Z direction. The second electrode 54 is in contact with the resin sheet 59. The second electrode 54 faces the first electrode 52 through the resin sheet 59. The area of ​​the first electrode 52 and the area of ​​the second electrode 54 may be the same, and the outer edges of the first electrode 52 and the outer edges of the second electrode 54 may coincide when viewed from the Z direction.

[0037] The first electrode 52, the resin sheet 59, and the second electrode 54 constitute a signal capacitor C1. The first electrode 52 and the second electrode 54 are a pair of electrode plates of the signal capacitor C1, and the resin sheet 59 is the dielectric of the signal capacitor C1. The capacitance required for the signal capacitor C1 to function as a coupling capacitor is, for example, 50 pF or more. In addition, the resin sheet 59 is required to withstand high voltages with an absolute value of 10 kV or more. Based on the above, the thickness of the resin sheet 59 is preferably 25 μm or more and 200 μm or less, and the area of ​​the first electrode 52 and the second electrode 54 is preferably 5 mm × 5 mm or more and 30 mm × 30 mm or less.

[0038] The third electrode 57 is positioned on the other side of the resin sheet 59 in the Z direction. The third electrode 57 is spaced apart from the first electrode 52 in the X direction. When viewed from the Z direction, the third electrode 57 is spaced apart from the first electrode 52 and is aligned with the first electrode 52 in the X direction. The third electrode 57 is in contact with the resin sheet 59. In the electron detector 5, the third electrode 57 is electrically connected to the anode electrode 511 via wiring WR.

[0039] The fourth electrode 58 is positioned on one side of the resin sheet 59 in the Z direction. The fourth electrode 58 is spaced apart from the second electrode 54 in the X direction. When viewed from the Z direction, the fourth electrode 58 is spaced apart from the second electrode 54 and is aligned with the second electrode 54 in the X direction. The fourth electrode 58 is in contact with the resin sheet 59. The fourth electrode 58 faces the third electrode 57 through the resin sheet 59. The area of ​​the third electrode 57 and the area of ​​the fourth electrode 58 may be the same, and when viewed from the Z direction, the outer edges of the third electrode 57 and the outer edges of the fourth electrode 58 may coincide.

[0040] The third electrode 57, the resin sheet 59, and the fourth electrode 58 constitute the return capacitor C2. The third electrode 57 and the fourth electrode 58 are a pair of electrode plates of the return capacitor C2, and the resin sheet 59 is the dielectric of the return capacitor C2. That is, the dielectric of the return capacitor C2 is the same as the dielectric of the signal capacitor C1. The capacitance of the return capacitor C2 is the same as that of the signal capacitor C1, for example, 50 pF or less. The thickness of the resin sheet 59 is preferably 25 μm or more and 200 μm or less, and the area of ​​the first electrode 52 and the second electrode 54 is preferably 5 mm × 5 mm or more and 30 mm × 30 mm or less.

[0041] The insulating substrate 61 is positioned on one side in the Z direction relative to the second electrode 54 and the fourth electrode 58. The insulating substrate 61 supports AD 51, the first electrode 52, the resin sheet 59, the second electrode 54, the third electrode 57, and the fourth electrode 58.

[0042] The insulating substrate 61 includes an insulating substrate body 613. The material of the insulating substrate body 613 is, for example, an insulating material such as FR-4. FR-4 is a composite material based on a glass fiber-reinforced epoxy resin. The thickness of the insulating substrate body 613 is, for example, 0.5 mm to 3 mm. The signal capacitor C1 and the return capacitor C2 are, for example, sheet-like structures with a thickness of several hundred μm. Therefore, the insulating substrate 61 functions as a reinforcing plate that reinforces the first electrode 52, the resin sheet 59 and the second electrode 54, as well as the third electrode 57, the resin sheet 59 and the fourth electrode 58.

[0043] The insulating substrate 61 further includes wiring (first wiring) 611 and wiring (first wiring) 612. Wiring 611 and wiring 612 are wirings that pass through the insulating substrate body 613. Wiring 611 is electrically connected to the second electrode 54. One end of wiring 611 is physically connected to the second electrode 54, and the other end of wiring 611 is exposed on one side in the Z direction relative to the insulating substrate body 613. In the electron detector 5, the other end of wiring 611 constitutes an electrode pad 611a on the surface of the insulating substrate body 613 opposite to the second electrode 54. Wiring 612 is electrically connected to the fourth electrode 58. One end of wiring 612 is physically connected to the fourth electrode 58, and the other end of wiring 612 is exposed on one side in the Z direction relative to the insulating substrate body 613. In the electron detector 5, the other end of the wiring 611 forms an electrode pad 612a on the surface of the insulating substrate body 613 opposite to the fourth electrode 58. When viewed from the Z direction, the electrode pad 612a is spaced apart from the electrode pad 611a, and in the X direction, it is aligned with the electrode pad 611a.

[0044] The insulating substrate 61 is circular when viewed from the Z direction, for example. For example, if the MCP210 is circular, the circular shape of the insulating substrate 61 facilitates alignment between the MCP210 and the AD51 in the X and Y directions. The first electrode 52, second electrode 54, third electrode 57, and fourth electrode 58 may be circular in shape to match the shape of the insulating substrate 61. However, the shapes of the insulating substrate 61 and each electrode are not limited to circular; they may be rectangular, elliptical, or polygonal. Also, when viewed from the Z direction, the first electrode 52 and the third electrode 57 may be positioned with the center of the insulating substrate 61 in between. That is, the first electrode 52 and the third electrode 57 may be positioned point-symmetrically from the center of the insulating substrate 61. Similarly, when viewed from the Z direction, the second electrode 54 and the fourth electrode 58 may be positioned with the center of the insulating substrate 61 in between. In other words, the second electrode 54 and the fourth electrode 58 may be arranged point-symmetrically with respect to the center of the insulating substrate 61.

[0045] The support portion 62 is positioned on one side of the insulating substrate 61 in the Z direction. The support portion 62 is fixed to the insulating substrate 61. The output portion 55 is positioned on one side of the support portion 62 in the Z direction. Therefore, in the Z direction, the insulating substrate 61, the support portion 62, and the output portion 55 are arranged in this order.

[0046] The support portion 62 supports the output unit 55 such that the output unit 55 and the second electrode 54 face each other via the insulating substrate 61, and a space SP1 is formed between the output unit 55 and the insulating substrate 61. When viewed from the Z direction, the output unit 55 faces the second electrode 54 via the insulating substrate 61, and also faces the fourth electrode 58 via the insulating substrate 61. The outer conductor 552 of the output unit 55 includes an enclosing portion 552A that surrounds the inner conductor 551, and a protruding portion 552B that protrudes outward from the enclosing portion 552A. In the electron detector 5, the inner conductor 551 and the enclosing portion 552A overlap with the second electrode 54. The protruding portion 552B surrounds the enclosing portion 552A so as to be in direct contact with it. The protruding portion 552B extends in the X direction so as to straddle the space between the second electrode 54 and the fourth electrode 58. As a result, the protruding portion 552B overlaps with the second electrode 54 in the portion closer to the second electrode 54 than the internal conductor 551, and overlaps with the fourth electrode 58 in the portion closer to the fourth electrode 58 than the internal conductor 551.

[0047] The support portion 62 includes a fixing portion 621 and an intermediate board 622. The fixing portion 621 fixes the intermediate board 622 to the insulating board 61. The fixing portion 621 also functions as a spacer. The support portion 62 adjusts the width L1 of the space SP1 between the insulating board 61 and the output portion 55 by the thickness of the fixing portion 621. The width L1 of the space SP1 is the distance in the Z direction between the insulating board 61 and the intermediate board 622. The width L1 of the space SP1 is greater than 1 / 3 times the thickness of the insulating board 61. Alternatively, the width L1 may be greater than 1 / 2 times the thickness of the insulating board 61. For example, the width L1 is 0.5 mm or more and 10 mm or less.

[0048] The relay board 622 includes wiring (second wiring) 622c that is electrically connected to the protruding portion 552B. Electrode pads are formed on the surface 622a of the relay board 622 on the side facing the output section 55 and on the surface 622b opposite to surface 622a. The electrode pad 622d formed on surface 622b may be electrically connected to the electrode pad formed on surface 622a via wiring 622c. The output section 55 is fixed to surface 622a. The protruding portion 552B of the output section 55 may be fixed to the relay board 622 by soldering to the electrode pad formed on surface 622a.

[0049] The relay substrate 622 has a through hole 622e that penetrates the relay substrate 622 in the Z direction. The position of the through hole 622e coincides with the position of the internal conductor 551 of the output section 55 in the X and Y directions. In the electron detector 5, the internal conductor 551 protrudes toward the insulating substrate 61 side than the external conductor 552 in the Z direction. The internal conductor 551 passes through the through hole 622e. The position of the tip of the internal conductor 551 in the Z direction coincides with the surface 622b.

[0050] The electron detector 5 further has a plurality of spring connectors 641, 642. Spring connector 641 electrically connects the output unit 55 and the second electrode 54. Spring connector 641 is located, for example, between wiring 611 and internal conductor 551. In the electron detector 5, one end of spring connector 641 is physically connected to electrode pad 611a, and the other end of spring connector 641 is physically connected to the tip of internal conductor 551. As a result, the electrical signal from AD 51 is transmitted from the second electrode 54 to the internal conductor 551 via wiring 611 and spring connector 641. Spring connector 642 electrically connects the output unit 55 and the fourth electrode 58. Spring connector 642 is located, for example, between wiring 612 and wiring 622c. In the electron detector 5, one end of spring connector 642 is physically connected to electrode pad 612a, and the other end of spring connector 642 is physically connected to electrode pad 622d. As a result, the current flowing through the return path is transmitted from the protruding portion 552B to the fourth electrode 58 via the wiring 622c, the spring connector 642, and the wiring 612.

[0051] Each spring connector 641, 642 is a flexible conductive connector. Spring connector 641 maintains contact pressure between electrode pad 611a and the tip of the internal conductor 551. Spring connector 642 maintains contact pressure between electrode pad 612a and electrode pad 622d.

[0052] As mentioned above, parasitic capacitance Cp is generated when the second electrode 54 and the outer conductor 552 face each other. Parasitic capacitance Cp can be expressed, for example, by "Cp = ε × (S / L1)". Here, the dielectric constant ε represents the dielectric constant of the dielectric of the parasitic capacitance Cp. In this case, the dielectric is the insulating substrate 61, the relay substrate 622, and the space SP1 interposed between the second electrode 54 and the output section 55. Note that if the electron detector 5 is placed under vacuum, the dielectric constant of space SP1 is the dielectric constant of vacuum. Area S is the area where the outer conductor 552 overlaps with the second electrode 54. If area S is a fixed value, the parasitic capacitance Cp decreases as the width L1 of space SP1 increases. However, if the width L1 is too large, while the parasitic capacitance Cp decreases, the parasitic inductance increases, which may result in increased ringing. Also, the size of the electron detector 5 will increase. Therefore, the width L1 may be adjusted so that both the parasitic capacitance Cp and the parasitic inductance are reduced to an extent that does not affect the waveform of the electrical signal. Alternatively, the width L1 may be adjusted considering the trade-off between the parasitic capacitance Cp and the size of the electron detector 5.

[0053] The insulating layer 63 includes a first insulating layer 631 and a second insulating layer 632. The first insulating layer 631 covers the first electrode 52 and the third electrode 57 on the other side in the Z direction relative to the resin sheet 59. The first insulating layer 631 is in contact with the resin sheet 59, except for the areas in contact with the first electrode 52 and the third electrode 57 on the resin sheet 59. However, the first insulating layer 631 does not cover the connection points between the anode electrode 511 and the third electrode 57 of AD 51 and the wiring WR. The connection points between the anode electrode 511 and the third electrode 57 and the wiring WR are exposed to the outside. The second insulating layer 632 covers the second electrode 54 and the fourth electrode 58 on one side in the Z direction relative to the resin sheet 59. The second insulating layer 632 is in contact with the resin sheet 59, except for the areas in contact with the second electrode 54 and the fourth electrode 58 on the resin sheet 59. Furthermore, the second insulating layer 632 is in contact with the AD51 side surface of the insulating substrate 61. The material of the insulating layer 63 is, for example, an insulating material such as an insulating resin. [Mechanism of Action and Effects]

[0054] In the electron detector 5, the first electrode 52 and the second electrode 54, which face each other via a resin sheet 59, function as a signal capacitor C1 that removes the DC component from the electrical signal detected by the electron detection unit 53, for example. As a result, the electrical signal from which the DC component has been removed is output from the output unit 55. Furthermore, the resin sheet 59 is used for the signal capacitor C1, and the electron detection unit 53, the resin sheet 59, and the second electrode 54 are supported by an insulating substrate 61. This ensures sufficient voltage resistance for the signal capacitor C1 and sufficient mechanical strength for the electron detector 5. In addition, the output unit 55 is supported by a support unit 62 so that a space SP1 is formed between the output unit 55 and the insulating substrate 61. This reduces the parasitic capacitance Cp generated between the output unit 55 and the second electrode 54, and suppresses ringing generated in the electrical signal due to the parasitic capacitance Cp. As a result, the quality of the electrical signal can be improved with the electron detector 5.

[0055] In the electron detector 5, the width L1 of the space SP1 in the Z direction is greater than 1 / 3 times the thickness of the insulating substrate 61. This makes it possible to sufficiently reduce the parasitic capacitance Cp generated between the output unit 55 and the second electrode 54.

[0056] In the electron detector 5, the support portion 62 is fixed to the insulating substrate 61. This allows the output portion 55 to be stably supported at a desired position relative to the insulating substrate 61.

[0057] The electron detector 5 is positioned on the other side of the resin sheet 59 in the Z direction and has a third electrode 57 spaced apart from the first electrode 52 in the X direction intersecting the Z direction, and a fourth electrode 58 positioned on the one side of the resin sheet 59 in the Z direction and spaced apart from the second electrode 54 in the X direction and facing the third electrode 57 via the resin sheet 59. The output unit 55 includes an internal conductor 551 electrically connected to the second electrode 54, and an external conductor 552 that surrounds the internal conductor 551 in a state of being electrically insulated from the internal conductor 551 and is electrically connected to the fourth electrode 58. Thus, just as the first electrode 52 and the second electrode 54 facing each other via the resin sheet 59 function as capacitors, the third electrode 57 and the fourth electrode 58 facing each other via the resin sheet 59 also function as capacitors. The first electrode 52 and the second electrode 54 function as signal capacitors C1 that remove the DC component from the electrical signal detected by the electron detection unit 53. As a result, the electrical signal from which the DC component has been removed is output from the internal conductor 551 of the output unit 55 via the second electrode 54. Meanwhile, the third electrode 57 and the fourth electrode 58 function as a return capacitor C2 positioned on the return path through which the return current from the external conductor 552 flows. This suppresses the degradation of the electrical signal waveform due to ringing and other factors.

[0058] In the electron detector 5, the insulating substrate 61 includes wiring 611 electrically connected to the second electrode 54, and the electron detector 5 further includes a spring connector 641 positioned between the wiring 611 and the internal conductor 551. This ensures that an electrical connection between the wiring 611 and the internal conductor 551 can be reliably achieved even if a space SP1 is formed between the output unit 55 and the insulating substrate 61.

[0059] In the electron detector 5, the insulating substrate 61 includes wiring 612 electrically connected to the fourth electrode 58, the support portion 62 includes wiring 622c electrically connected to the protruding portion 552B of the outer conductor 552, and the electron detector 5 further includes a spring connector 642 positioned between the wiring 612 and the wiring 622c. This ensures that an electrical connection between the wiring 612 and the wiring 622c is reliably achieved even if a space SP1 is formed between the output portion 55 and the insulating substrate 61.

[0060] In the electron detector 5, the electron detection unit 53 further includes an AD51 electrically connected to the first electrode 52, and the AD51 detects electrons emitted from the MCP21. According to this configuration, electrons can be detected with high sensitivity due to the avalanche effect of the AD51.

[0061] The electron detector 5 further has an insulating layer 63 that covers the second electrode 54 and the fourth electrode 58 on one side in the Z direction relative to the resin sheet 59, and the first electrode 52 and the third electrode 57 on the other side in the Z direction relative to the resin sheet 59. This makes it possible to suppress the deterioration of each electrode.

[0062] The charged particle detector 1 comprises an electron detector 5 and an electron emission unit 2 that emits electrons upon the incidence of charged particles. This configuration allows for improved electrical signal quality in the electron detector 5.

[0063] In the charged particle detector 1, the electron emission unit 2 includes an MCP 21. This allows the electrons emitted from the electron emission unit 2 to be amplified as secondary electrons, thereby increasing the electrical signal output from the electron detector 5. Furthermore, it enables the emission of secondary electrons with a high amplification factor. [Differentiation]

[0064] The present invention is not limited to the embodiments described above. As shown in Figure 5, the first modified electron detector 5A differs from electron detector 5 in that it further has a resistor 65 electrically connected between the fourth electrode 58 and the outer conductor 552. The resistor 65 connects, for example, the electrode pad formed on the surface 622a to the protruding portion 552B. The resistor 65 functions as a damping resistor to suppress ringing of the electrical signal output from the signal output terminal 56.

[0065] Figure 6 is a graph showing an example of the behavior of an electrical signal when the resistance value of resistor 65 is changed. In Figure 6, the electrical signal is displayed as the output voltage. The horizontal axis of Figure 6 represents time, and the vertical axis of Figure 6 represents the normalized output voltage with the peak of the output voltage matched to -100%. Ringing occurs in the output voltage when the output voltage changes from -100% to 0%. It can be seen that the ringing is largest when the resistance value of resistor 65 is 0Ω, and decreases as the resistance value of resistor 65 increases. It can also be seen that as the resistance value of resistor 65 increases, the amount of fluctuation from 0% after the output voltage changes to 0% is suppressed. On the other hand, it can be seen that as the resistance value of resistor 65 increases, the time it takes for the output voltage to reach 0% increases. In the electron detector 5A, resistor 65 absorbs the high-frequency components of the electrical signal, so ringing generated in the electrical signal can be suppressed more reliably.

[0066] As shown in Figure 7, the second modified electron detector 5B differs from the electron detector 5 in the configuration of the support portion 62. The support portion 62A of the electron detector 5B includes fixing portions 625 and 626. The fixing portions 625 and 626 fix the output portion 55 to the insulating substrate 61. The fixing portions 625 and 626 are connectors with the Z direction as their longitudinal direction. One end of the fixing portions 625 and 626 is physically connected to the electrode pads on the insulating substrate 61. Of these, the fixing portion 626 is physically connected to the electrode pad 612a. The other end of the fixing portions 625 and 626 is physically connected to the protruding portion 552B. The support portion 62A adjusts the width L1 of the space SP1 between the insulating substrate 61 and the output portion 55 by the thickness of the fixing portions 625 and 626. In addition, the internal conductor 551 protrudes towards the insulating substrate 61 in the Z direction more than the external conductor 552. The length of the protruding portion of the internal conductor 551 is, for example, the same as the thickness of the fixing portions 625 and 626. The tip of the internal conductor 551 is physically connected to the electrode pad 611a.

[0067] The fixed parts 625 and 626 are conductive connectors. Fixed part 626 electrically connects the fourth electrode 58 and the outer conductor 552 via wiring 612. As a result, the current flowing through the return path is transmitted from the protruding part 552B to the fourth electrode 58 via fixed part 626 and wiring 612.

[0068] The internal conductor 551 is electrically connected to one of the second electrode 54 and the fourth electrode 58, and the external conductor 552 is electrically connected to the other of the second electrode 54 and the fourth electrode 58. In the embodiments and modifications described above, an example was given in which one electrode is the second electrode 54, that is, an example in which the internal conductor 551 is electrically connected to the second electrode 54, but the internal conductor 551 may also be electrically connected to the fourth electrode 58. Also, in the embodiments and modifications described above, an example was given in which the other electrode is the fourth electrode 58, that is, an example in which the external conductor 552 is electrically connected to the fourth electrode 58, but the external conductor 552 may also be electrically connected to the second electrode 54. As shown in Figure 8, the electron detector 5C of the third modification differs from the electron detector 5 in that the internal conductor 551 is electrically connected to the fourth electrode 58 and the external conductor 552 is electrically connected to the second electrode 54.

[0069] The tip of the internal conductor 551 is electrically connected to the electrode pad 612a via a spring connector 642. In the electronic detector 5C, the electrical signal from AD 51 flows through the wiring WR and is transmitted to the third electrode 57. The electrical signal is then transmitted from the fourth electrode 58 to the internal conductor 551 via the wiring 612 and the spring connector 642. In other words, in the electronic detector 5C, the third electrode 57, the resin sheet 59, and the fourth electrode 58 constitute a signal capacitor C1. The protruding portion 552B is electrically connected to the electrode pad 611a via the wiring 622c, the electrode pad 622d, and the spring connector 641. As a result, the current flowing through the return path is transmitted from the protruding portion 552B to the second electrode 54 via the wiring 622c, the spring connector 641, and the wiring 611. In other words, in the electronic detector 5C, the first electrode 52, the resin sheet 59, and the second electrode 54 constitute a return capacitor C2.

[0070] The insulating substrate 61 may include wiring (first wiring) electrically connected to the second electrode 54 or the fourth electrode 58. In the embodiment described above, an example was given in which the insulating substrate 61 includes wiring (first wiring) 611 and wiring (first wiring) 612, but for example, the insulating substrate 61 may not include either wiring 611 or wiring 612. In this case, instead of wiring 612, a through hole that penetrates the insulating substrate 61 in the Z direction may be further provided. A conductive wire may be inserted through this through hole. One end of the conductive wire may be physically connected to the spring connector 642, and the other end of the conductive wire may be physically connected to the fourth electrode 58.

[0071] The relay board 622 may include wiring (second wiring) electrically connected to the internal conductor 551 or the external conductor 552. In the embodiment described above, an example was described in which the relay board 622 includes wiring (second wiring) 622c electrically connected to the external conductor 552, but the relay board 622 may also include wiring electrically connected to the internal conductor 551. For example, the relay board 622 may be further provided with wiring in place of the through hole 622e at a position that coincides with the internal conductor 551 in the X and Y directions. This wiring is a second wiring different from wiring 622c and is formed within the relay board 622 from surface 622b to surface 622a. The internal conductor 551 may be electrically connected to spring connector 641 or spring connector 642 via the wiring.

[0072] The electron detector 5 only needs to have a spring connector positioned between the first wiring and the internal conductor 551 or the external conductor 552. In the embodiment described above, an example was given in which the spring connector 641 is positioned between the wiring 611 (first wiring) and the internal conductor 551, but the spring connectors 641 and 642 may also be positioned between the wiring 611 and the external conductor 552. For example, the spring connectors 641 and 642 may be electrically connected to the external conductor 552 without the wiring. As an example, the relay board 622 may be further provided with a through hole that penetrates the relay board 622 in the Z direction, instead of the wiring 622c. A conductive wire may be inserted through this through hole. One end of the conductive wire may be physically connected to the protruding portion 552B, and the other end of the conductive wire may be physically connected to the spring connector 641 or the spring connector 642.

[0073] The electron detection unit 53 does not necessarily have to include AD51. In this case, for example, the electron detection unit 53 is composed of a first electrode 52. The first electrode 52 may also serve as the signal capacitor C1. As shown in Figure 9, the electron detector 5D of the fourth modified example differs from the electron detector 5 in that it does not have AD51. In the charged particle detector 1A including the electron detector 5D, the electron emission unit 2 may also include an MCP unit 22 composed of two MCPs. In the charged particle detector 1A, the wiring WR electrically connects the third electrode 57 and the MCP unit 22. This forms a return path from the outer conductor 552 to the MCP unit 22. The first electrode 52 functions as an anode electrode, which is an electron capture electrode. For example, the first electrode 52 detects electrons emitted from the MCP unit 22. In this case, unlike AD51, the first electrode 52 does not have an amplification function. The electron incident surface of the first electrode 52 is not covered by the first insulating layer 631 and is exposed to the outside. In the charged particle detector 1A, the first electrode 52 serves as both the electrode for electron detection and the electrode for the coupling capacitor, thus simplifying the configuration of the electron detection unit 53.

[0074] The electron emission unit 2 may include other electron multiplier elements in place of or together with the MCP21. As shown in Figure 10, the modified charged particle detector 1B differs from the charged particle detector 1A in that the electron emission unit 2 includes a dynode unit 23 instead of the MCP21. The dynode unit 23 includes multiple dynodes. In the dynode unit 23, each stage of dynodes emits electrons as secondary electrons and passes them to the next stage, thereby increasing the number of electrons in steps. In Figure 10, only the final stage dynode is shown. In the charged particle detector 1B, the wiring WR connects the third electrode 57 and the dynode unit 23. This forms a return path from the outer conductor 552 to the dynode unit 23. With the charged particle detector 1B, since the electrons emitted from the electron emission unit 2 are multiplied as secondary electrons, the electrical signal output from the electron detector 5 can be made larger. In addition, secondary electron emission with a high amplification factor can be achieved.

[0075] Any combination is possible in the various modifications described above. For example, the outer conductor 552 may be electrically connected to the second electrode 54 via a resistor 65, and the inner conductor 551 may be electrically connected to the fourth electrode 58. Also, for example, in the electron detector 5B shown in Figure 7, the resistor 65 may be physically connected between the fixed part 626 and the electrode pad 612a, or between the fixed part 626 and the protruding part 552B. Also, for example, in the electron detector 5D shown in Figure 9 or the electron detector 5E shown in Figure 10, the inner conductor 551 may be electrically connected to the fourth electrode 58, or the outer conductor 552 may be electrically connected to the second electrode 54. Also, for example, in the electron detector 5D or the electron detector 5E, the relay board 622 may include wiring electrically connected to the inner conductor 551, or the spring connectors 641, 642 may be physically connected to the inner conductor 551 or the outer conductor 552 without wiring.

[0076] In the embodiments and modifications described above, an example was given in which the electron detector 5 is applied to the charged particle detector 1. However, the electron detector 5 may also be applied to an electron tube that includes a photocathode that converts photons into photoelectrons. The electron detector 5 may be applied to, for example, a photomultiplier tube or a hybrid photodetector (HPD). A photomultiplier tube includes an electron multiplier unit that multiplies photoelectrons emitted from the photocathode to emit secondary electrons. This electron multiplier unit corresponds to the electron emission unit 2 in the charged particle detector 1. An HPD does not include a configuration corresponding to the electron emission unit 2. In an HPD, photoelectrons emitted from the photocathode directly enter the electron detector 5.

[0077] Based on the embodiments and modifications described above, the charged particle detector of the present invention can also be described as follows.

[0078] The charged particle detector of the present invention is [1] "an electron emission unit that emits electrons upon incidence of charged particles, and an electron detector that outputs the electrons emitted from the electron emission unit as an electrical signal, wherein the electron detector includes a first electrode and an electron detection unit that detects the electrons emitted from the electron emission unit, a resin sheet disposed on one side in a first direction with respect to the first electrode, a second electrode disposed on the one side in a first direction with respect to the resin sheet and facing the first electrode via the resin sheet, an insulating substrate disposed on the one side in a first direction with respect to the second electrode and supporting the electron detection unit, the resin sheet and the second electrode, an output unit disposed on the one side in a first direction with respect to the insulating substrate and electrically connected to the second electrode and outputting the electrical signal, and a support unit that supports the output unit such that the output unit and the second electrode face each other via the insulating substrate and a space is formed between the output unit and the insulating substrate, the charged particle detector."

[0079] The charged particle detector of the present invention may also be [2] "the charged particle detector according to [1] above, wherein the width of the space in the first direction is greater than 1 / 3 times the thickness of the insulating substrate."

[0080] The charged particle detector of the present invention may also be the charged particle detector according to [1] or [2] above, wherein the support portion is fixed to the insulating substrate.

[0081] The charged particle detector of the present invention may also be [4] "the charged particle detector according to any one of [1] to [3] above, wherein the electron detector further comprises a third electrode disposed on the other side in the first direction with respect to the resin sheet and spaced apart from the first electrode in a second direction intersecting the first direction, and a fourth electrode disposed on the one side in the first direction with respect to the resin sheet and spaced apart from the second electrode in a second direction and facing the third electrode through the resin sheet, and the output unit comprises an internal conductor electrically connected to one of the second electrode and the fourth electrode, and an external conductor surrounding the internal conductor in a state of being electrically insulated from the internal conductor and electrically connected to the other electrode of the second electrode and the fourth electrode."

[0082] The charged particle detector of the present invention may also be the charged particle detector according to [4] above, wherein the insulating substrate includes wiring electrically connected to the second electrode or the fourth electrode, and the electron detector further includes a spring connector disposed between the wiring and the inner conductor or the outer conductor.

[0083] The charged particle detector of the present invention may also be the charged particle detector according to [4] above, wherein the insulating substrate includes a first wiring electrically connected to the second electrode or the fourth electrode, the support includes a second wiring electrically connected to the internal conductor or the external conductor, and the electron detector further includes a spring connector disposed between the first wiring and the second wiring.

[0084] The charged particle detector of the present invention may also be the charged particle detector according to any one of the above [4] to [6], wherein the electron detector further has a damping resistor electrically connected between the other electrode of the second electrode and the fourth electrode and the outer conductor.

[0085] The charged particle detector of the present invention may also be the charged particle detector according to any one of the above [1] to [7], wherein the electron detection unit further includes an avalanche diode electrically connected to the first electrode, and the avalanche diode detects the electrons emitted from the electron emission unit.

[0086] The charged particle detector of the present invention may also be [9] "a charged particle detector according to any one of [1] to [7] above, wherein the first electrode detects the electrons emitted from the electron emission unit."

[0087] The charged particle detector of the present invention may also be

[10] "a charged particle detector according to any one of [1] to [9] above, wherein the electron emission unit includes a microchannel plate."

[0088] The charged particle detector of the present invention may also be

[11] "a charged particle detector according to any one of [1] to [9] above, wherein the electron emission unit includes a plurality of dynodes."

[0089] The charged particle detector of the present invention may also be

[12] "the charged particle detector according to any one of [1] to

[11] above, wherein the electron detector further has an insulating layer that covers the second electrode on one side in the first direction with respect to the resin sheet and covers the first electrode on the other side in the first direction with respect to the resin sheet." [Explanation of Symbols]

[0090] 1, 1A, 1B... Charged particle detector, 2... Electron emission unit, 23... Multiple dynodes (dynode units), 5, 5A, 5B, 5C, 5D, 5E... Electron detector, 51... AD (avalanche diode), 52... First electrode, 53... Electron detection unit, 54... Second electrode, 55... Output unit, 57... Third electrode, 58... Fourth electrode, 59... Resin sheet, 61... Insulating substrate, 62, 62A... Support unit, 63... Insulating layer, 65... Resistor, 551... Internal conductor, 552... External conductor, 611, 612... Wiring (first wiring), 622c... Wiring (second wiring), 641, 642... Spring connector, L1... Width, SP1... Space.

Claims

1. An electron detection unit including a first electrode for detecting incident electrons, A resin sheet disposed on one side in the first direction relative to the first electrode, A second electrode is positioned on one side in the first direction relative to the resin sheet and faces the first electrode via the resin sheet, An insulating substrate is positioned on one side in the first direction relative to the second electrode and supports the electron detection unit, the resin sheet, and the second electrode. An output unit is provided, which is positioned on one side in the first direction with respect to the insulating substrate, is electrically connected to the second electrode, and outputs an electrical signal. An electron detector comprising a support portion that supports the output portion such that the output portion and the second electrode face each other via the insulating substrate and a space is formed between the output portion and the insulating substrate.

2. The electron detector according to claim 1, wherein the width of the space in the first direction is greater than 1 / 3 the thickness of the insulating substrate.

3. The electron detector according to claim 1 or 2, wherein the support portion is fixed to the insulating substrate.

4. A third electrode is positioned on the other side in the first direction relative to the resin sheet, and is spaced apart from the first electrode in a second direction intersecting the first direction, The system further comprises a fourth electrode which is positioned on one side of the resin sheet in the first direction, spaced apart from the second electrode in the second direction, and facing the third electrode via the resin sheet, The output unit is, An internal conductor electrically connected to one of the second electrode and the fourth electrode, The electron detector according to claim 1 or 2, comprising an outer conductor that surrounds the inner conductor in a state of being electrically insulated from the inner conductor and is electrically connected to the other electrode of the second electrode and the fourth electrode.

5. It also features a spring connector, The insulating substrate includes wiring electrically connected to the second electrode or the fourth electrode. The electron detector according to claim 4, wherein the spring connector is disposed between the wiring and the internal conductor or the external conductor.

6. It also features a spring connector, The insulating substrate includes a first wiring that is electrically connected to the second electrode or the fourth electrode. The electronic detector according to claim 4, wherein the support portion includes a second wiring electrically connected to the internal conductor or the external conductor, and the spring connector is disposed between the first wiring and the second wiring.

7. The electron detector according to claim 4, further comprising a resistor electrically connected between the other electrode of the second and fourth electrodes and the outer conductor.

8. The electron detection unit further includes an avalanche diode electrically connected to the first electrode, The avalanche diode detects the electrons, as described in claim 1 or 2.

9. The electron detector according to claim 1 or 2, wherein the first electrode detects the electron.

10. The electron detector according to claim 1 or 2, further comprising an insulating layer that covers the second electrode on one side of the resin sheet in the first direction and covers the first electrode on the other side of the resin sheet in the first direction.

11. The electron detector according to claim 1 or 2, A charged particle detector comprising an electron emission unit that emits electrons upon the incidence of charged particles.

12. The charged particle detector according to claim 11, wherein the electron emission unit includes a microchannel plate.

13. The charged particle detector according to claim 11, wherein the electron emission unit includes a plurality of dynodes.

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