A multiplication acquisition device for weak analog signals from low-energy ion detectors

Abstract

The present invention belongs to the technical field of low-energy ion detection and relates to a multiplication acquisition device for weak analog signals of a low-energy ion detector, which is used to perform square root or cube root operations on current signals collected by the low-energy ion detector. The device includes: a current-voltage conversion circuit, a subtraction proportional operation circuit, and a square root operation circuit or a cube root operation circuit connected in series in sequence, wherein the current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal; the subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector; the square root operation circuit is used to perform nonlinear conversion according to the output analog signal intensity of the subtraction proportional operation circuit, enhance weak signals with high gain, and enhance strong signals with lower gain to achieve a square root function; the cube root operation circuit is used to perform nonlinear conversion according to the output signal intensity of the subtraction proportional operation circuit to achieve a cube root function.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-energy ion detection, and in particular relates to a multiplication acquisition device for weak analog signals of a low-energy ion detector. Background Art

[0002] Accurate detection of low-energy ions is crucial in today's low-energy particle physics research and applications. Low-energy ion detectors are particularly useful in fields such as plasma physics, astrophysics, and space physics, where they are widely used to obtain particle parameters and study plasma environment characteristics. However, low-energy ion signals are typically weak, especially in vacuum environments or space plasmas. Current signals often range from microamperes to picoamperes, and can often vary by more than 40dB within a single acquisition. Stable and precise acquisition of these weak signals is a key challenge in ensuring detector performance.

[0003] The difficulties in acquiring weak current signals mainly lie in the low signal intensity, rapid rate of change, and susceptibility to external interference, which requires the acquisition device to have extremely high sensitivity and signal-to-noise ratio. In addition, the stable acquisition of microcurrent signals requires not only a high-precision amplification device, but also a large dynamic range to cope with complex and changing experimental environments and application requirements. When faced with extremely low currents, traditional signal acquisition systems often have problems such as excessive noise, insufficient sensitivity, and limited dynamic range, resulting in data acquisition accuracy and reliability that cannot meet the requirements of high-precision detection. With the development of science and technology, analog multiplier technology has been widely used in the field of microcurrent signal enhancement and processing due to its high gain and low noise characteristics. This provides an effective solution for the acquisition of microcurrent signals in low-energy ion detectors.

[0004] Therefore, there is an urgent need to develop a micro-current acquisition device combined with an analog multiplier and related methods, which can not only greatly improve the sensitivity of the low-energy ion detector, but also expand its dynamic range and achieve stable and high-precision acquisition of weak current signals. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and propose a multiplication acquisition device for weak analog signals of low-energy ion detectors.

[0006] In order to achieve the above-mentioned object, the present invention proposes a multiplication acquisition device for weak analog signals of low-energy ion detectors, which is used to perform square root operation on the current signal collected by the low-energy ion detector. The device comprises: a current-voltage conversion circuit, a subtraction proportional operation circuit and a square root operation circuit connected in series, wherein:

[0007] The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal;

[0008] The subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector;

[0009] The square root operation circuit is used to perform nonlinear conversion according to the output analog signal strength of the subtraction proportional operation circuit, enhance weak signals with high gain and enhance strong signals with lower gain, thereby realizing the square root function.

[0010] Preferably, the current-voltage conversion circuit includes an operational amplifier and a jumper resistor, the reverse input terminal of the operational amplifier is connected to the low-energy ion detector and the jumper resistor, the tiny signal collected by the ion detector is converted into a voltage signal through the jumper resistor, and the positive input terminal is connected to the reference voltage V REF connected to ensure that the circuit operates in a stable state; a feedback capacitor is connected in parallel between the inverting input and output terminals of the operational amplifier to ensure the stability and linearity of the output signal at the output terminal of the operational amplifier.

[0011] Preferably, the subtraction proportional operation circuit includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the output terminal of the current-voltage conversion circuit through a series resistor, and the positive input terminal is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor. REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

[0012] Preferably, the square root operation circuit includes an operational amplifier and an analog multiplier, wherein:

[0013] The reverse input terminal of the operational amplifier is divided into two paths, one path is connected to the output terminal of the subtraction proportional operation circuit through a series resistor, and the other path is connected to the output terminal of the analog multiplier through a series resistor. The positive input terminal of the operational amplifier is grounded after passing through the series resistor, and the output terminal of the operational amplifier is connected to the two input terminals of the analog multiplier through a parallel diode and capacitor.

[0014] On the other hand, the present invention also proposes a multiplication acquisition device for weak analog signals of low-energy ion detectors, which is used to perform a cube root operation on the current signal collected by the low-energy ion detector. The device includes: a current-voltage conversion circuit, a subtraction proportional operation circuit and a cube root operation circuit connected in series, wherein:

[0015] The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal;

[0016] The subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector;

[0017] The cube root operation circuit is used to perform nonlinear conversion according to the output signal strength of the subtraction proportional operation circuit to realize the cube root function.

[0018] Preferably, the current-voltage conversion circuit includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the low-energy ion detector for inputting a small current signal, and the forward input terminal is connected to the reference voltage V REF The operational amplifier is connected to ensure that the circuit operates in a stable state; the feedback resistor and capacitor are connected in parallel between the inverting input terminal and the output terminal of the operational amplifier to ensure the stability and linearity of the output signal of the output terminal of the operational amplifier.

[0019] Preferably, the subtraction proportional operation circuit includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the output terminal of the current-voltage conversion circuit through a series resistor, and the positive input terminal is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor. REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

[0020] Preferably, the cube root operation circuit includes an operational amplifier and an analog multiplier, wherein:

[0021] The reverse input terminal of the operational amplifier is divided into two paths, one path is connected to the output terminal of the subtraction proportional operation circuit through a series resistor, and the other path is connected to the output terminal of the first analog multiplier through a series resistor. The positive input terminal of the operational amplifier is grounded after passing through the series resistor. The output terminal of the operational amplifier is connected to both input terminals of the second analog multiplier and one input terminal of the first analog multiplier through a parallel diode and capacitor. The other input terminal of the first analog multiplier is connected to the output terminal of the second analog multiplier.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The present invention proposes an analog multiplication acquisition device suitable for weak signals of low-energy ion detectors, which can achieve high-precision enhancement and stable acquisition of tiny current signals. By introducing an analog multiplier, the dynamic range of signal acquisition is effectively expanded, and the signal is enhanced and processed to ensure the stability and accuracy of signal acquisition quality, thereby meeting the demand for high-precision measurement of weak signals and improving the reliability and anti-interference ability of the system.

[0024] It is widely applicable to fields such as plasma physics, space exploration, and materials science. It will significantly improve the measurement accuracy and data reliability of low-energy ion detectors in complex environments, providing important support for technological progress in related fields such as plasma physics research and space low-energy ion detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a general analog multiplier circuit;

[0026] Figure 2 It is a series circuit of two analog multipliers;

[0027] Figure 3 This is the schematic diagram of the square root operation circuit;

[0028] Figure 4 It is the overall square root signal processing circuit diagram;

[0029] Figure 5 It is the circuit diagram of cube root operation;

[0030] Figure 6 It is the overall cube root signal processing circuit diagram;

[0031] Figure 7 This is the simulation diagram of the overall square root signal processing circuit;

[0032] Figure 8 This is the simulation diagram of the overall cube root signal processing circuit;

[0033] Figure 9 This is a comparison chart of signals collected by linear, square root and cube root circuits. DETAILED DESCRIPTION

[0034] The present invention relates to an analog multiplication acquisition device suitable for weak signals from low-energy ion detectors. In particular, the device incorporates an analog multiplier to perform square root and cube root operations in analog signal processing, enabling stable, high-precision acquisition of weak signals with a wide dynamic range. This device, used in low-energy particle detection environments, accurately measures the weak current signals generated by the detectors, enhances and processes the signals, and ensures stable and accurate signal acquisition quality.

[0035] 1 Principle Design

[0036] In order to achieve accurate acquisition and amplification and enhanced processing of current signals with a large dynamic range, it is difficult for general linear amplifier circuits to complete the task. Taking into account the characteristics of various signal processing circuits and the characteristics of low-energy ion parameters, a weak signal acquisition system combined with analog multipliers has been developed. In view of the two characteristics of low-energy ion detectors, that is, the current collected is very weak and the dynamic range varies with the low-energy ion density, an amplifier circuit based on square or cubic operations combined with analog multipliers is designed to perform pre-processing before analog-to-digital conversion of the current. Its core is the combination operation of analog multipliers. General analog multipliers such as Figure 1 shown.

[0037] Unlike the volt-ampere characteristics of resistors, the voltage output across an analog multiplier exhibits a multiplicative change as the input changes. Squaring or cubing operations significantly compress the dynamic range and are sensitive to small current changes. Therefore, using a square or cube amplifier circuit can help compress the dynamic range of the collected current and improve the system's sensitivity to small current acquisition. The relationship between the output and input of an analog multiplier is shown in Equation (1).

[0038] U o =kU x U y (1)

[0039] Where U o is the output voltage of the analog multiplier, U x 、U y is the input voltage of the analog multiplier, k is a constant. x =U y When , the above formula can be transformed into:

[0040]

[0041] When two analog multipliers are Figure 2 When connected in series, the relationship between the output and input is:

[0042]

[0043] As shown in equations (2) and (3), there is a square or cube relationship between the output and input of the analog multiplier. Therefore, analog multipliers can be used to form square or cube operation circuits.

[0044] 1) Square root signal processing circuit

[0045] like Figure 3As shown, the analog multiplier is the core of the square root operation circuit, which can multiply two input signals and output the product signal. In the square root operation circuit, the characteristics of the multiplier are used to construct the square relationship between the output signal and the input signal. The operational amplifier serves as the feedback and control element in the square root circuit to ensure that the circuit can operate stably. The purpose of connecting a diode in series and a capacitor in parallel at the output of the operational amplifier is to prevent the occurrence of latch-up phenomenon and reduce noise and interference in the signal, thereby playing a role in signal smoothing. The operational amplifier adjusts the signal in the circuit through the feedback mechanism to ensure that the output signal and the input signal meet the square relationship. The operational amplifier using negative feedback is combined with the analog multiplier to form a closed-loop system to realize the square root function. Specifically, the square root circuit ensures that the output signal meets the following requirements through feedback adjustment:

[0046]

[0047] Among them, u i is the input signal, which must satisfy u i >0.u o is the output signal. k is a constant.

[0048] The complete square root signal processing circuit is as follows Figure 4 The specific circuit structure is divided into the following three parts: current-voltage conversion circuit, subtraction proportional operation circuit and square root operation circuit.

[0049] The main function of the current-voltage conversion circuit is to convert the tiny current signal collected by the low-energy ion detector into a voltage signal. The reverse input terminal of the operational amplifier is connected to the low-energy ion detector for the input of the micro-current signal. The positive input terminal is connected to the reference voltage V REF The circuit is connected to ensure stable operation and can collect the tiny current from the low-energy ion detector. The feedback resistor and capacitor ensure the stability and linearity of the output signal. At the same time, the resistor is connected to the subsequent subtraction proportional operation circuit for further signal processing.

[0050] The function of the subtraction proportional operation circuit is to convert the scanning reference voltage V applied to the ion detector into REF Subtract; make the final current signal more accurate. The operational amplifier stabilizes the output through the feedback resistor and capacitor, and is compared with the reference voltage V REF connections for precise signal processing.

[0051] The square root operation circuit is used to perform nonlinear conversion on the output signal of the subtraction proportional operation circuit. Due to the characteristics of the square root operation, the positive and negative values ​​of the input voltage must be controlled to ensure that ku iThe square root circuit performs nonlinear amplification based on the signal strength. For smaller signals, the amplification factor is higher, thereby improving the signal-to-noise ratio of small signals. For larger signals, the amplification factor is reduced, ensuring a larger dynamic range at the signal acquisition end.

[0052] The output of the circuit is connected to the filtering circuit and the analog-to-digital conversion circuit for subsequent processing.

[0053] 2) Cube root signal processing circuit

[0054] like Figure 5 As shown in the figure, the negative feedback branch of the operational amplifier of the cube root operation circuit uses two analog multipliers in series to ensure that the output signal satisfies:

[0055]

[0056] Among them, u i is the input signal, u o is the output signal, and k is a constant.

[0057] The complete cube root signal processing circuit is as follows Figure 6 The specific circuit structure is also divided into the following three parts: current-voltage conversion circuit, subtraction proportional operation circuit and cube root operation circuit.

[0058] Due to the characteristics of the cube root operation, this circuit does not need to control the positive and negative values ​​of the input voltage and has a larger dynamic range. Compared with the square root operation circuit, the cube root signal processing circuit has fewer restrictions and a wider range of applications.

[0059] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0060] Example 1

[0061] To verify the effectiveness of the square root and cube root calculation circuits in this invention, we used simulation software to build and simulate the circuits. The goal of the experiment was to validate the effectiveness of the circuit design, specifically its ability to amplify and stably acquire microcurrent signals with high precision, by processing simulated signals. The following is a detailed experimental verification process and analysis of the results.

[0062] like Figure 7 As shown, according to the principle of the invention, a square root operation circuit based on an analog multiplier and an operational amplifier is built in the simulation software. Specifically, it includes: a current-voltage conversion circuit, a subtraction proportional operation circuit and a square root operation circuit connected in series, wherein,

[0063] The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal; it includes an operational amplifier and a jumper resistor, the reverse input end of the operational amplifier is connected to the low-energy ion detector and the jumper resistor, the tiny signal collected by the ion detector is converted into a voltage signal through the jumper resistor, and the positive input end is connected to the reference voltage V REF connected to ensure that the circuit operates in a stable state; a feedback capacitor is connected in parallel between the inverting input and output terminals of the operational amplifier to ensure the stability and linearity of the output signal at the output terminal of the operational amplifier.

[0064] The subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector; it includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the output terminal of the current-voltage conversion circuit through a series resistor, and the positive input terminal is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor. REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

[0065] The square root operation circuit is used to perform nonlinear conversion based on the output analog signal strength of the subtraction proportional operation circuit, enhance weak signals with high gain and enhance strong signals with lower gain to achieve the square root function. It includes an operational amplifier and an analog multiplier, wherein:

[0066] The reverse input terminal of the operational amplifier is divided into two paths, one path is connected to the output terminal of the subtraction proportional operation circuit through a series resistor, and the other path is connected to the output terminal of the analog multiplier through a series resistor. The positive input terminal of the operational amplifier is grounded after passing through the series resistor, and the output terminal of the operational amplifier is connected to the two input terminals of the analog multiplier through a parallel diode and capacitor.

[0067] The circuit receives a tiny current signal as input, passes it through a current-to-voltage conversion circuit, a subtraction proportional circuit, and finally a square root circuit for nonlinear amplification. A negative feedback mechanism ensures that the output voltage signal and the input current signal have a square relationship.

[0068] Experimental results show that the output signal of the square root signal processing circuit closely matches the square of the input signal. For input signals of varying amplitudes, the output voltage consistently and accurately reflects signal changes, and exhibits a high signal-to-noise ratio under small signal conditions. The experiments validate the circuit's effectiveness in processing microcurrent signals, particularly in dynamic range expansion and signal amplification.

[0069] Example 2

[0070] like Figure 8As shown, the simulation software is also used to build a cube root signal processing circuit. The operational amplifier realizes the cube root operation through two analog multipliers connected in series. It includes: a current-voltage conversion circuit, a subtraction proportional operation circuit and a cube root operation circuit connected in series in sequence, wherein,

[0071] The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal; it includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the low-energy ion detector for inputting the tiny current signal, and the positive input terminal is connected to the reference voltage V REF The operational amplifier is connected to ensure that the circuit operates in a stable state; the feedback resistor and capacitor are connected in parallel between the inverting input terminal and the output terminal of the operational amplifier to ensure the stability and linearity of the output signal of the output terminal of the operational amplifier.

[0072] The subtraction proportional operation circuit is used to convert the scanning reference voltage V applied to the ion detector into REF Subtract; including an operational amplifier, the inverting input terminal of the operational amplifier is connected to the output terminal of the current-voltage conversion circuit through a series resistor, and the positive input terminal is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

[0073] A cube root operation circuit is used to perform nonlinear conversion based on the output signal strength of a subtraction proportional operation circuit to achieve a cube root function. The circuit comprises an operational amplifier and an analog multiplier. The inverting input of the operational amplifier is divided into two paths: one path is connected to the output of the subtraction proportional operation circuit via a series resistor, and the other path is connected to the output of a first analog multiplier via a series resistor. The positive input of the operational amplifier is grounded after passing through the series resistor. The output of the operational amplifier is connected to both inputs of a second analog multiplier and one input of the first analog multiplier via a parallel diode and capacitor. The other input of the first analog multiplier is connected to the output of the second analog multiplier.

[0074] This circuit eliminates the need to control the positive and negative values ​​of the input signal, and through its circuit structure, it implements cubic operational amplification of tiny current signals. This design is used to verify the ability to process signals with a wider range of variations.

[0075] The cubing signal processing circuit also achieved the expected results, with the output signal and the cubic relationship of the input current meeting theoretical expectations. Simulation results showed that the circuit performed well over a wider dynamic range, adapting to input signals of varying strengths and maintaining high accuracy and stability even under high input signal conditions.

[0076] In addition, in order to verify the effectiveness and performance of the present invention, we also used the AD633 analog multiplier and the OPA2196 operational amplifier to build an overall square root and cube root signal processing circuit according to the design scheme, and ensured the correctness of the circuit connection and the stability of the components. The circuit has been repeatedly adjusted and calibrated to ensure the stable operation of the operational circuit, and a standard current source is used as the input signal. Different current values ​​are set, and the input range covers from picoamperes to microamperes to simulate weak current signals in a low-energy ion detection environment. The output voltage of the circuit is measured by a high-precision multimeter, and the output voltage values ​​under different input current conditions are recorded, and the measurement environment is ensured to be stable to avoid the influence of external noise and temperature changes on the measurement results. According to the relationship between the output voltage and the input current, the model of the overall square root and cube root signal processing circuit is used to perform data calculations to verify whether the output voltage meets the theoretical expectations. The experimental results are as follows Figure 9 By analyzing experimental data under different current input conditions, the experimental results confirmed that the relationship between the circuit's output voltage and input current meets the theoretical expectations of the overall square root and cube root signal processing circuit, verifying the effectiveness of the circuit design. The experimental results also show that the device has high accuracy in collecting and processing small current signals, and the dynamic range of the acquisition meets expectations.

[0077] Conclusion

[0078] The present invention proposes a weak signal acquisition device and method combined with an analog multiplier suitable for low-energy ion detectors, which successfully solves the technical problem that weak signals in low-energy particle detection are difficult to acquire stably and accurately. By introducing an analog multiplier to realize the square or cubic operation of the analog signal, the device not only improves the amplification accuracy of the microcurrent signal, but also effectively expands the dynamic range of acquisition, enhances the system's anti-interference ability and data acquisition stability. Experimental results show that the present invention has broad application prospects in many fields such as plasma physics, space low-energy ion detection, and materials science, and will provide reliable technical support for related technical research and industrial applications. In short, the present invention has opened up a new solution path for the microcurrent acquisition technology of low-energy ion detectors, which has important practical application value and theoretical significance.

[0079] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A multiplication acquisition device for weak analog signals of a low-energy ion detector, used for performing square root operation on the current signal collected by the low-energy ion detector, characterized in that: The device comprises: a current-voltage conversion circuit, a subtraction proportional operation circuit and a square root operation circuit connected in series, wherein: The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal; the tiny current signal is in the microampere to picoampere range; The subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector; The square root operation circuit is used to perform nonlinear conversion according to the output analog signal strength of the subtraction proportional operation circuit, enhance weak signals with high gain and enhance strong signals with lower gain, thereby realizing the square root function; The square root operation circuit includes an operational amplifier and an analog multiplier, wherein: The reverse input terminal of the operational amplifier is divided into two paths, one path is connected to the output terminal of the subtraction proportional operation circuit through a series resistor, and the other path is connected to the output terminal of the analog multiplier through a series resistor. The positive input terminal of the operational amplifier is grounded after passing through the series resistor, and the output terminal of the operational amplifier is connected to the two input terminals of the analog multiplier through a parallel diode and capacitor.

2. The multiplication acquisition device for weak analog signals of low-energy ion detectors according to claim 1, characterized in that: The current-voltage conversion circuit includes an operational amplifier and a jumper resistor. The reverse input terminal of the operational amplifier is connected to the low-energy ion detector and the jumper resistor. The tiny signal collected by the ion detector is converted into a voltage signal through the jumper resistor. The positive input terminal is connected to the reference voltage V REF connected to ensure that the circuit operates in a stable state; a feedback capacitor is connected in parallel between the inverting input and output terminals of the operational amplifier to ensure the stability and linearity of the output signal at the output terminal of the operational amplifier.

3. The multiplication acquisition device for weak analog signals of low-energy ion detectors according to claim 2, characterized in that: The subtraction proportional operation circuit includes an operational amplifier, the reverse input end of the operational amplifier is connected to the output end of the current-voltage conversion circuit through a series resistor, and the positive input end is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor. REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

4. A multiplication acquisition device for weak analog signals of a low-energy ion detector, used for performing a cube root operation on the current signal collected by the low-energy ion detector, characterized in that: The device comprises: a current-voltage conversion circuit, a subtraction proportional operation circuit and a cube root operation circuit connected in series, wherein: The current-voltage conversion circuit is used to convert the tiny current signal collected by the low-energy ion detector into a voltage signal; the tiny current signal is in the microampere to picoampere range; The subtraction proportional operation circuit is used to subtract the scanning reference voltage applied to the ion detector; The cube root operation circuit is used to perform nonlinear conversion according to the output signal strength of the subtraction proportional operation circuit to achieve the cube root function; The cube root operation circuit includes an operational amplifier and an analog multiplier, wherein: The reverse input terminal of the operational amplifier is divided into two paths, one path is connected to the output terminal of the subtraction proportional operation circuit through a series resistor, and the other path is connected to the output terminal of the first analog multiplier through a series resistor. The positive input terminal of the operational amplifier is grounded after passing through the series resistor. The output terminal of the operational amplifier is connected to both input terminals of the second analog multiplier and one input terminal of the first analog multiplier through a parallel diode and capacitor. The other input terminal of the first analog multiplier is connected to the output terminal of the second analog multiplier.

5. The multiplication acquisition device for weak analog signals of low-energy ion detectors according to claim 4, characterized in that: The current-voltage conversion circuit includes an operational amplifier, the reverse input terminal of the operational amplifier is connected to the low-energy ion detector for inputting a small current signal, and the forward input terminal is connected to the reference voltage V REF The operational amplifier is connected to ensure that the circuit operates in a stable state; the feedback resistor and capacitor are connected in parallel between the inverting input terminal and the output terminal of the operational amplifier to ensure the stability and linearity of the output signal of the output terminal of the operational amplifier.

6. The multiplication acquisition device for weak analog signals of low-energy ion detectors according to claim 5, characterized in that: The subtraction proportional operation circuit includes an operational amplifier, the reverse input end of the operational amplifier is connected to the output end of the current-voltage conversion circuit through a series resistor, and the positive input end is divided into two paths, one path is connected to the ground after passing through the series resistor, and the other path is connected to the reference voltage V after passing through the series resistor. REF Connected, a feedback resistor and capacitor are connected in parallel between the inverting input and output of the operational amplifier.

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