Quantum current combination measurement device and method based on high-precision vacuum pressure control

Abstract

This invention provides a quantum current combined measurement device and method based on high-precision vacuum pressure control. The device includes: a vacuum chamber; a vacuum pump connected to the vacuum chamber; a vacuum pressure control component connected to the vacuum chamber; a high-current measurement component disposed within the high-current chamber; and a low-current measurement component disposed within the vacuum chamber. This invention regulates the vacuum level within the vacuum chamber through the vacuum pressure control component. When measuring extremely weak currents in a single electron stage, the vacuum level is reduced, and the signal is guided and collected by the low-current measurement component, enabling signal ion multiplication detection. When the current increases to the nanoampere level or above, the vacuum level is increased, switching to the high-current measurement component for direct charge collection measurement. This quantum current combined measurement device uses vacuum level as a key control variable, integrating the high sensitivity of the low-current measurement component to weak signals with the high-precision measurement capability of the high-current measurement component to strong signals into a single system.

Description

Technical Field

[0001] This invention relates to the field of quantum current measurement technology, and more specifically, to a quantum current combined measurement device and method based on high-precision vacuum pressure control. Background Technology

[0002] Currently, the definition of ampere has been traced back to the fundamental physical constant: the electron charge. This shift marks a milestone in the quantization of electric current. Measuring the electron beam that constitutes the quantum current is a crucial step in constructing a quantum current standard device.

[0003] In this step, the photocathode electron gun first generates an electron beam consisting of multiple electrons. This electron beam is then drawn out and directed into a pre-designed vacuum tube to form a quantum current. Completing a counting measurement of the electron beam constitutes the measurement of the quantum current. Achieving high accuracy in counting electron beams from single-electron to ampere levels is one of the core objectives of realizing quantum current standards.

[0004] Among the many traditional electron beam detection techniques, intercept measurement is the one with relatively high accuracy. (1) For extremely weak electron beams ranging from single electron level to nanoampere, the typical measurement method is the microchannel plate. Its principle can be simply described as follows: the electrons to be measured enter a small channel with a special surface material, and then collide with the inner wall of the channel multiple times to generate an electron multiplication effect, eventually forming a detectable signal. Its disadvantage is that when the intensity of the electron beam reaches the milliampere level, its gain is prone to saturation and nonlinearity, affecting the measurement accuracy. (2) For electron beams of picoampere level and above, the Faraday cup is the most commonly used detection method. It is a cup-shaped collector that directly measures the intensity of the electron beam by absorbing the charge of the electron beam. Its disadvantage is that it needs to work under high vacuum, and electron beams with a single electron level intensity are below the lower limit of the signal detected by the Faraday cup and cannot be effectively read out. Summary of the Invention

[0005] In view of this, the present invention proposes a quantum current combined measurement device and method based on high-precision vacuum pressure control, aiming to solve the problem that existing traditional single measurement techniques cannot cover the current intensity range from single electrons to ampere levels.

[0006] On one hand, this invention proposes a quantum current combined measurement device based on high-precision vacuum pressure control. The device includes: a vacuum chamber; a vacuum pump connected to the vacuum chamber for evacuating the vacuum chamber; a vacuum pressure control component connected to the vacuum chamber for adjusting and controlling the vacuum level of the vacuum chamber to a low or high vacuum level; a high-current-intensity measurement component disposed within the high-vacuum chamber for measuring the charge collection intensity of the quantum current under high vacuum conditions to obtain the corresponding current signal; and a low-current-intensity measurement component disposed within the vacuum chamber for guiding and collecting signal ions generated by the ionization of gas with single electrons down to the nA level under low vacuum conditions, multiplying the signal ions, and converting them into corresponding current signals.

[0007] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, the low-current-strength measurement component includes: an electric field guiding component and a microchannel plate; wherein, an injection connection port is provided on the side wall of the vacuum chamber for connecting an electron gun to inject the quantum current along a preset injection direction; the microchannel plate is arranged perpendicular to the preset injection direction, and the guiding electric field component is used to form a guiding electric field, which guides the signal ions generated by the ionization of quantum currents from single electrons to nA levels under low vacuum to the microchannel plate, and then the microchannel plate receives and multiplies the signal ions and converts them into corresponding current signals.

[0008] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, the electric field guiding component includes an upper electrode plate and a lower electrode plate; wherein the upper electrode plate and the lower electrode plate are spaced apart and arranged in parallel to form an electrostatic field, applying Coulomb force to charged signal ions to change their trajectory and guide them to the microchannel plate that serves as a collector.

[0009] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, the microchannel plate is disposed on the wall surface of the upper electrode plate facing the lower electrode plate, or the microchannel plate is disposed on the wall surface of the lower electrode plate facing the upper electrode plate.

[0010] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, the side wall of the vacuum chamber is provided with an injection connection port for connecting an electron gun to inject the quantum current along a preset injection direction; the high-current measurement component is a Faraday cup, which is disposed in the vacuum chamber and in the preset injection direction, with the Faraday cup arranged opposite to the injection connection port.

[0011] Furthermore, the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control further includes a signal readout component, which is connected to the high current intensity measurement component and the low current intensity measurement component respectively, for reading the current signals acquired by the high current intensity measurement component and the low current intensity measurement component.

[0012] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, a measurement connection port is provided on the side wall of the vacuum chamber, and the high current measurement component is connected to the vacuum chamber through an interface flange.

[0013] Furthermore, in the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control, when the vacuum chamber is in a low vacuum state, the vacuum pressure inside the vacuum chamber is 10. -2 ~1000Pa.

[0014] On the other hand, the present invention also proposes a quantum current combined measurement method based on high-precision vacuum pressure control. This method uses the aforementioned quantum current combined measurement device based on high-precision vacuum pressure control and includes the following steps: evacuating the vacuum chamber using the vacuum pump of the measurement device to adjust the vacuum level of the vacuum chamber to a high vacuum level; performing charge collection measurement on the quantum current injected into the vacuum chamber using the high-current-intensity measurement component to obtain a first current signal corresponding to the quantum current current intensity; determining whether the maximum value of the first current signal is greater than the lower limit of the measurement range of the high-current-intensity measurement component, and whether the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within a preset measurement period; if the maximum amplitude of the first current signal is greater than the lower limit of the high-current-intensity measurement range, and the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period, the first current signal is used as the current data of the quantum current, completing the measurement of the quantum current.

[0015] Furthermore, in the above-mentioned quantum current combined measurement method based on high-precision vacuum pressure control, if the maximum amplitude of the first current signal is less than or equal to the lower limit of the high current intensity measurement range, or the fluctuation range of the first current signal is greater than or equal to 0.1% of the average value of the first current signal within a preset measurement period, the vacuum pressure control component adjusts the vacuum level in the vacuum chamber to a low vacuum level; the low current intensity measurement component guides and collects signal ions generated by the ionization of gas by the quantum current under low vacuum, multiplies the signal ions and converts them into a corresponding second current signal, which serves as the current data of the quantum current.

[0016] This invention provides a quantum current combined measurement device and method based on high-precision vacuum pressure control. By adjusting the vacuum level within the vacuum chamber through a vacuum pressure control component, it adapts to and switches between two different quantum current measurement mechanisms. Specifically, when measuring extremely weak currents at the single-electron level, the vacuum level is reduced. Utilizing the characteristic that the number of ionized signal ions generated by the electron beam in the gas is proportional to the vacuum level and current intensity, the signal is guided and collected by a low-current-intensity measurement component, and the signal ions are multiplied for detection. When the current increases to the nanoampere level or above, the vacuum level is increased to switch to a high-current-intensity measurement component for direct charge collection measurement. This quantum current combined measurement device uses vacuum level as a key control variable, integrating the high sensitivity of the low-current-intensity measurement component to weak signals with the high-precision measurement capability of the high-current-intensity measurement component to strong signals into a single system. This achieves high-accuracy measurement of quantum currents across the entire range from the single-electron level to the ampere level, effectively overcoming the shortcomings of traditional interceptor measurement devices, such as narrow measurement range, gain saturation under strong currents, or inability to detect weak currents. It addresses the problem that traditional single-measurement techniques cannot cover the current intensity range from single electrons to amperes. Therefore, this quantum current combined measurement device and method is suitable for quantum current measurement from single electrons to ampere-level current intensity, and can be further extended to current intensity detection in various electron beam transport devices. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of a quantum current combined measurement device based on high-precision vacuum pressure control provided in an embodiment of the present invention;

[0019] Figure 2 A cross-sectional view of a quantum current combined measurement device based on high-precision vacuum pressure control provided in an embodiment of the present invention;

[0020] Figure 3 A cross-sectional rendering of a quantum current combination measurement device based on high-precision vacuum pressure control provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the structure of the quantum current combined measurement device based on high-precision vacuum pressure control for high-vacuum measurement provided in an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the structure of the quantum current combined measurement device based on high-precision vacuum pressure control for measuring under low vacuum conditions, provided in an embodiment of the present invention;

[0023] Figure 6 A flowchart illustrating a quantum current combination measurement method based on high-precision vacuum pressure control, provided in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Vacuum chamber, 11-Injection connection port, 12-Measurement connection port, 2-Vacuum pump, 3-Vacuum pressure control component, 4-High flow rate measurement component, 5-Low flow rate measurement component, 51-Electric field guiding component, 511-Upper electrode plate, 512-Lower electrode plate, 52-Microchannel plate, 53-Insulating support plate, 6-Signal readout component, 7-Interface flange. Detailed Implementation

[0026] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Device Example:

[0028] See Figures 1 to 5 The figure illustrates a preferred structure of a quantum current combined measurement device based on high-precision vacuum pressure control provided by an embodiment of the present invention. As shown, the quantum current combined measurement device includes: a vacuum chamber 1, a vacuum pump 2, a vacuum pressure control component 3, a high current intensity measurement component 4, a low current intensity measurement component 5, and a signal readout component 6.

[0029] Vacuum pump 2 is connected to vacuum chamber 1 and is used to evacuate vacuum chamber 1. Specifically, vacuum chamber 1 can be a vertically arranged columnar structure, providing a vacuum environment for the main measuring devices, i.e., providing a sealed environment for the entire measurement process, especially when combined with vacuum pressure control component 3 to form a sealed chamber with adjustable vacuum level. Vacuum pump 2 can be a combination of dry backing pump and molecular pump, i.e., including dry backing pump and molecular pump, which can generate, maintain and control the vacuum environment required by vacuum chamber 1 over a wider vacuum pressure range. In this embodiment, vacuum pump 2 is connected to vacuum chamber 1 through a pipe and is responsible for evacuating and maintaining the required basic vacuum environment within vacuum chamber 1. In this embodiment, the sidewall of vacuum chamber 1 (e.g., Figure 3An injection connection port 11 may be provided on the left side wall (as shown) for connecting an electron gun to inject the quantum current along a preset injection direction. Figure 4 and Figure 5 In the diagram, the large black arrow indicates the preset injection direction, which is the direction of quantum current injection and the direction of quantum current movement. It can move from left to right.

[0030] The vacuum pressure control component 3 is connected to the vacuum chamber 1 and is used to adjust and control the vacuum level of the vacuum chamber 1 to adjust the vacuum level in the vacuum chamber 1 to a low vacuum level or a high vacuum level.

[0031] Specifically, to achieve precise and dynamic control of the vacuum level, the vacuum pressure control component 3 can be a high-precision vacuum pressure control system, which is then installed on the vacuum chamber 1. By adjusting the gas flow rate, the vacuum pressure within the chamber is changed, i.e., the vacuum level within the vacuum chamber 1 is adjusted to a low or high vacuum level. The vacuum pressure control component 3 can be the microenvironment pressure control system disclosed in Chinese Publication No. CN110797278A. In this embodiment, the vacuum pressure within the vacuum chamber 1 corresponding to a low vacuum level can be 10... -2 ~1000Pa, the vacuum pressure corresponding to high vacuum is 10 -2 ~10 -5 Pa.

[0032] The high current intensity measurement component 4 is installed in the vacuum chamber and is used to perform charge collection measurement of quantum current intensity under high vacuum to obtain the current signal corresponding to the quantum current intensity, especially to perform charge collection measurement of quantum current intensity at the nA level and above under high vacuum to obtain the current signal corresponding to the quantum current intensity.

[0033] Specifically, the high-current-intensity measurement component 4 can be a Faraday cup. The Faraday cup is positioned within a vacuum chamber and along a preset injection direction, meaning it is placed on the quantum current injection path. As a cup-shaped collector, it directly measures the electron beam intensity by absorbing electron beam charge, i.e., performing direct charge collection measurement. In this embodiment, the Faraday cup is arranged opposite to the injection connection port 11 to facilitate charge collection measurement. Since the Faraday cup needs to operate under high vacuum, and the intensity of an electron beam with a single-electron-level intensity is below the lower limit of the signal detected by the Faraday cup, it cannot effectively read the intensity of the electron beam. Therefore, the Faraday cup primarily performs charge collection measurement for quantum current intensities of nA and above. For extremely weak electron beams from the single-electron-level to the nanoampere level, the corresponding current signal will fluctuate significantly, resulting in unstable data. In such cases, the low-current-intensity measurement component 5 is needed for current measurement. In other words, when the electron beam intensity reaches the high-precision measurement range of the Faraday cup, the vacuum level is increased, and the Faraday cup is used to measure the current intensity under high electron beam intensities. In this embodiment, the sidewall of the vacuum chamber 1 (e.g. Figure 3 The right side wall shown is provided with a measurement connection port 12. The high current intensity measurement component 4 is connected to the vacuum chamber 1 through the interface flange 7. The interface flange 7 serves as the end cover of the vacuum chamber 1, which encapsulates the internal structure and leads out the electrical connection.

[0034] To obtain the intensity of the extremely weak electron beam, preferably, the vacuum chamber 1 is also equipped with a low current intensity measurement component 5, which is used to guide and collect signal ions generated by the quantum current ionization of gas from single electrons to the nA level under low vacuum, multiply the signal ions and convert them into corresponding current signals.

[0035] Specifically, vacuum level and signal gain are linearly related. Therefore, when the measured electron beam is at a very weak current intensity of a single electron level, the vacuum level can be reduced to increase the number of ionized signal ion pairs generated by the electron beam passing through the target region. This number is proportional to the vacuum level and the quantum current intensity. Therefore, when the measured electron beam is at a very weak current intensity of a single electron level, the vacuum level in the vacuum chamber 1 is adjusted to a low vacuum level by the vacuum pressure control component 3 in conjunction with the vacuum pump 2 to increase the number of ionized signal ion pairs generated by the electron beam passing through the target region. The low current intensity measurement component 5 guides and collects the signal ions generated by the quantum current ionization of the gas from a single electron level to the nA level, multiplies the signal ions, and converts them into corresponding current signals.

[0036] In this embodiment, the signal readout component 6 is connected to the high-current measurement component 4 and the low-current measurement component 5 respectively, and is used to read the current signals acquired by the high-current measurement component 4 and the low-current measurement component 5. Specifically, the signal readout component 6 can be a signal receiver, and is connected to the high-current measurement component 4 and the low-current measurement component 5 respectively through a signal shielding wire. The shielding wire is used for electromagnetic shielding and signal transmission. The signal receiving component is used to receive the current signals output by the high-current measurement component 4 and the low-current measurement component 5. That is, the electrical signals detected by the high-current measurement component 4 and the low-current measurement component 5 are transmitted and processed through the signal readout component 6, thereby completing the full-range quantum current measurement from single electron to ampere level.

[0037] See also Figures 2 to 5 The low current intensity measurement component 5 includes an electric field guiding component 51 and a microchannel plate 52. The microchannel plate 52 is arranged perpendicular to the preset injection direction. The guiding electric field component is used to form a guiding electric field. The guiding electric field guides the signal ions generated by the ionization of quantum currents from single electrons to nA level under low vacuum to the microchannel plate 52. The microchannel plate 52 then receives and multiplies the signal ions and converts them into corresponding current signals.

[0038] Specifically, the electric field guiding component 51 is disposed within the vacuum chamber 1 to generate a guiding electric field that guides signal ions generated by the ionization of quantum currents ranging from single electrons to nA to the microchannel plate 52. In this embodiment, the guiding electric field is directed downwards (e.g., ...). Figure 5 The microchannel plate 52 is arranged (as indicated by the black arrow) to guide the signal ions generated by the ionization of a single electron to the nA level of the quantum current downwards, guiding them to the microchannel plate 52. In this embodiment, the electric field guiding component 51 can also support the microchannel plate 52, i.e., it is a support component that supports the microchannel plate 52. The microchannel plate 52 is arranged perpendicular to the quantum current injection path on one side of the quantum current injection path (e.g., as indicated by the black arrow). Figure 5 The lower side shown can be set on the electric field guiding component 51 to perform high-gain and high-sensitivity detection. That is, the electron to be measured enters a tiny channel with a special surface material, and then collides with the inner wall of the channel multiple times to generate an electron multiplication effect, and finally form a signal that can be detected, especially for measuring weak quantum current bundles from single electrons to nA level.

[0039] See also Figures 3 to 5 The electric field guiding component 51 includes an upper electrode 511 and a lower electrode 512; wherein the upper electrode 511 and the lower electrode 512 are arranged at intervals and in parallel to form an electrostatic field, applying a Coulomb force to the charged signal ions to change their trajectory and guide them to the microchannel plate 52, which serves as a collector. Specifically, the upper electrode 511 and the lower electrode 512 are respectively disposed on both sides of the quantum current injection path (e.g., Figure 5As shown on the upper and lower sides), 2n padding plates are evenly distributed on the upper electrode 511 and lower electrode 512 to shape the edge shape of the guiding electric field, thereby reducing the lateral component of the guiding electric field and allowing the signal ions to move vertically downwards as much as possible. The upper electrode 511 and lower electrode 512 can be supported within the vacuum chamber 1 by insulating plates and insulating rods. In this embodiment, the microchannel plate 52 is disposed on the wall surface of the lower electrode 512 facing the upper electrode 511 (e.g., ...). Figure 5 The microchannel plate 52 is disposed on the upper wall surface shown. Of course, in other embodiments, the microchannel plate 52 may also be disposed on the wall surface of the upper electrode plate 511 facing the lower electrode plate 512. An insulating support plate 53 may also be provided between the microchannel plate 52 and the lower electrode plate 512 to achieve insulating support.

[0040] In this embodiment, the interface flange 7 encapsulates the main components such as the microchannel plate 52, the electric field guiding component 51, and the Faraday cup within the vacuum chamber 1, and is welded with a high-voltage interface and a signal interface for vacuum encapsulation, high voltage, and signal feeding.

[0041] In summary, the quantum current combined measurement device based on high-precision vacuum pressure control provided in this embodiment adjusts the vacuum level in the vacuum chamber 1 through the vacuum pressure control component 3, thereby adapting to and switching between two different quantum current measurement mechanisms. In particular, when measuring the extremely weak current of a single electron stage, by reducing the vacuum level, the signal is guided and collected by the low-current-intensity measurement component 5, taking advantage of the characteristic that the number of ionized signal ions generated by the electron beam in the gas is proportional to the vacuum level and the current intensity, and the signal ions are multiplied and detected. When the current is increased to the nanoampere level or above, the high-current-intensity measurement component 4 is switched to perform direct charge collection measurement by increasing the vacuum level. This quantum current combined measurement device uses vacuum degree as a key control variable, integrating the high sensitivity of the low-current measurement component 5 for weak signals with the high-current measurement capability of the high-current measurement component 4 for strong signals into a single system. This achieves high-accuracy measurement of quantum currents across the entire range, from the single-electron level to the ampere level. It effectively overcomes the shortcomings of traditional interceptor-type measurement devices, such as narrow measurement range, gain saturation under high current, or inability to detect weak currents. This addresses the problem that traditional single-measurement techniques cannot cover the current range from single electrons to amperes. Therefore, this quantum current combined measurement device is suitable for measuring quantum currents from single electrons to amperes and can be further extended to current detection in various electron beam transport devices.

[0042] Method Implementation Examples:

[0043] See Figure 6 The figure shows a flowchart of a quantum current combination measurement method based on high-precision vacuum pressure control provided in an embodiment of the present invention. As shown, this quantum current combination measurement method uses the aforementioned device to measure quantum current and may include the following steps:

[0044] Step S1: The vacuum chamber is evacuated by the vacuum pump of the measuring device to adjust the vacuum level of the vacuum chamber 1 to a high vacuum level.

[0045] Specifically, the vacuum chamber 1 is evacuated by the vacuum pump 2 to adjust the vacuum level of the vacuum chamber 1 to a high vacuum level. The vacuum level can also be adjusted in conjunction with the vacuum pressure control component 3.

[0046] Step S2: The quantum current injected into the vacuum chamber is charged and measured using a high current intensity measurement component to obtain the first current signal corresponding to the quantum current intensity.

[0047] Specifically, when the vacuum chamber is adjusted to a high vacuum level, the electron beam is directly captured by the high-current-intensity measurement component, i.e., the Faraday cup, and then read out by the signal readout component to obtain the first current signal corresponding to the quantum current intensity. This allows for real-time measurement of the first current signal corresponding to the quantum current intensity over a given period of time.

[0048] Step S3: Determine whether the maximum value of the first current signal within the preset measurement period is greater than the lower limit of the measurement range of the high current intensity measurement component, and whether the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period.

[0049] Specifically, it is determined whether the first current signal is stable, especially whether the maximum value of the first current signal is greater than the lower limit of the measurement range of the high current intensity measurement component, and whether the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period. The lower limit of the measurement range of the Faraday cup is 1 nA.

[0050] Step S4: If the maximum amplitude of the first current signal within the preset measurement period is greater than the lower limit of the high current intensity measurement range, and the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period, the first current signal is used as the current data of the quantum current to complete the measurement of the quantum current.

[0051] Specifically, if the maximum amplitude of the first current signal within the preset measurement period is greater than the lower limit of the high current intensity measurement range, and the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period, then the first current signal is relatively stable. In other words, the currently injected subcurrent to be measured is within the signal monitoring area of ​​the Faraday cup detection, which is higher than or equal to the lower limit of the Faraday cup detection signal. The current signal of the subcurrent to be measured is effectively read out. Therefore, the currently injected subcurrent to be measured is an electron beam cluster of nanoamperes or higher. The first current signal is used as the current data of the quantum current to complete the measurement of the quantum current of the electron beam cluster of nanoamperes or higher.

[0052] Step S5: If the maximum amplitude of the first current signal during the preset measurement period is less than or equal to the lower limit of the high current intensity measurement range, or the fluctuation range of the first current signal is greater than or equal to 0.1% of the average value of the first current signal during the preset measurement period, the vacuum level in the vacuum chamber is adjusted to a low vacuum level by the vacuum pressure control component.

[0053] Specifically, if the maximum amplitude of the first current signal is less than or equal to the lower limit of the high current intensity measurement range, or if the fluctuation range of the first current signal is greater than or equal to 0.1% of the average value of the first current signal within the preset measurement period, then the electron beam cluster with a single electron-level intensity is below the lower limit of the signal detected by the Faraday cup, and the Faraday cup cannot effectively read the current signal of the currently injected sub-current to be measured. To achieve the measurement of the currently injected sub-current to be measured, the vacuum degree in the vacuum chamber 1 is adjusted to a low vacuum degree by the vacuum pressure control component 3, that is, the vacuum pressure in the vacuum chamber 1 is adjusted to 10. -2 ~1000Pa.

[0054] Step S6: The signal ions generated by the ionization of gas by the quantum current are guided and collected under low vacuum by the low current intensity measurement component. The signal ions are multiplied and converted into the corresponding second current signal as the current data of the quantum current.

[0055] Specifically, the weak electron beam that makes up the quantum current ionizes the gas in the vacuum chamber 1, and the generated signal ions are guided to the microchannel plate 52 by the upper and lower electrode plates 512 located in the vacuum chamber 1. The microchannel plate 52 multiplies the signal ions and reads them out by the signal readout component 6 as the current data of the quantum current.

[0056] In summary, the quantum current combined measurement method based on high-precision vacuum pressure control provided in this embodiment adjusts the vacuum level in the vacuum chamber 1 through the vacuum pressure control component 3, thereby adapting to and switching between two different quantum current measurement mechanisms. In particular, when measuring the extremely weak current of a single electron stage, by reducing the vacuum level, the signal is guided and collected by the low-current-intensity measurement component 5, taking advantage of the characteristic that the number of ionized signal ions generated by the electron beam in the gas is proportional to the vacuum level and the current intensity, and the signal ions are multiplied and detected. When the current is increased to the nanoampere level or above, the high-current-intensity measurement component 4 is switched to perform direct charge collection measurement by increasing the vacuum level. This quantum current combined measurement device uses vacuum degree as a key control variable, integrating the high sensitivity of the low-current measurement component 5 for weak signals with the high-current measurement capability of the high-current measurement component 4 for strong signals into a single system. This achieves high-accuracy measurement of quantum currents across the entire range, from the single-electron level to the ampere level. It effectively overcomes the shortcomings of traditional interceptor-type measurement devices, such as narrow measurement range, gain saturation under high current, or inability to detect weak currents. This addresses the problem that traditional single-measurement techniques cannot cover the current range from single electrons to amperes. Therefore, this quantum current combined measurement device is suitable for measuring quantum currents from single electrons to amperes and can be further extended to current detection in various electron beam transport devices.

[0057] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0058] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A quantum current combination measurement method based on high-precision vacuum pressure control, characterized in that, The quantum current combined measurement device based on high-precision vacuum pressure control includes the following steps: The vacuum chamber of the measuring device is evacuated by the vacuum pump of the measuring device to adjust the vacuum level of the vacuum chamber to a high level. The high-current-intensity measurement component of the measurement device performs charge collection measurement on the quantum current injected into the vacuum chamber to obtain the first current signal corresponding to the quantum current intensity. Determine whether the maximum value of the first current signal is greater than the lower limit of the measurement range of the high current intensity measurement component, and whether the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within a preset measurement period; If the maximum amplitude of the first current signal is greater than the lower limit of the high current intensity measurement range, and the fluctuation range of the first current signal is less than 0.1% of the average value of the first current signal within the preset measurement period, the first current signal is used as the current data of the quantum current to complete the measurement of the quantum current. The quantum current combined measurement device based on high-precision vacuum pressure control includes: Vacuum chamber; A vacuum pump, which is connected to the vacuum chamber, is used to evacuate the vacuum chamber. A vacuum pressure control component, which is connected to the vacuum chamber, is used to adjust and control the vacuum level of the vacuum chamber to adjust the vacuum level inside the vacuum chamber to a low vacuum level or a high vacuum level. A high current intensity measurement component is disposed in the vacuum chamber and is used to perform charge collection measurement of quantum current intensity under high vacuum to obtain the current signal corresponding to the quantum current intensity. A low-current-intensity measurement component is disposed within the vacuum chamber to guide and collect signal ions generated by quantum current ionization of gas at the single-electron to nA level under low vacuum conditions, multiply the signal ions and convert them into corresponding current signals; The low-current measurement component includes: an electric field guiding component and a microchannel plate; wherein... The side wall of the vacuum chamber is provided with an injection connection port for connecting an electron gun to inject the quantum current along a preset injection direction; The microchannel plate is arranged perpendicular to the preset injection direction. The electric field guiding component is used to form a guiding electric field. The guiding electric field guides the signal ions generated by the ionization of quantum currents from single electrons to nA level to the microchannel plate under low vacuum. The microchannel plate then receives and multiplies the signal ions and converts them into corresponding current signals. The side wall of the vacuum chamber is provided with an injection connection port for connecting an electron gun to inject the quantum current along a preset injection direction; The high-current-intensity measurement component is a Faraday cup, which is disposed in the vacuum chamber and in the preset injection direction, with the Faraday cup arranged opposite to the injection connection port; The vacuum chamber is at a low vacuum degree, and a vacuum pressure in the vacuum chamber is 10 -2 1000 Pa; The vacuum chamber is at a high vacuum degree, and a vacuum pressure in the vacuum chamber is 10 -2 ~10 -5 Pa.

2. The quantum current combination measurement method based on high-precision vacuum pressure control according to claim 1, characterized in that, If the maximum amplitude of the first current signal is less than or equal to the lower limit of the high current intensity measurement range, or if the fluctuation range of the first current signal is greater than or equal to 0.1% of the average value of the first current signal within the preset measurement period, the vacuum level in the vacuum chamber is adjusted to a low vacuum level by the vacuum pressure control component. The low-current-strength measurement component guides and collects signal ions generated by the ionization of gas by the quantum current under low vacuum. The signal ions are multiplied and converted into a corresponding second current signal, which serves as the current data of the quantum current.

3. The quantum current combination measurement method based on high-precision vacuum pressure control according to claim 1, characterized in that, The electric field guiding component includes: an upper electrode plate and a lower electrode plate; wherein... The upper and lower electrodes are arranged at intervals and in parallel to form an electrostatic field, which applies Coulomb force to charged signal ions to change their trajectory and guide them to the microchannel plate that serves as a collector.

4. The quantum current combination measurement method based on high-precision vacuum pressure control according to claim 3, characterized in that, The microchannel plate is disposed on the wall surface of the upper electrode plate facing the lower electrode plate, or the microchannel plate is disposed on the wall surface of the lower electrode plate facing the upper electrode plate.

5. The quantum current combination measurement method based on high-precision vacuum pressure control according to claim 1, characterized in that, Also includes: A signal readout component is connected to the high current intensity measurement component and the low current intensity measurement component, respectively, and is used to read the current signals acquired by the high current intensity measurement component and the low current intensity measurement component.

6. The quantum current combination measurement method based on high-precision vacuum pressure control according to claim 1, characterized in that, The vacuum chamber has a measurement connection port on its side wall, and the high current intensity measurement component is connected to the vacuum chamber through an interface flange.

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