Substance detection system, method, and diagnostic device

Abstract

The invention provides a substance detection system and method and diagnostic equipment, and belongs to the technical field of electron diffraction, and the substance detection system comprises an electron emission module, a laser emission module and a detection module. The electron emission module comprises an electron emitter and a grid electrode. The electron emission module is used for emitting electronic pulses to the to-be-detected sample in the excited state. The grid electrode is arranged on the periphery of the electron emitter and regulates and controls electron beams emitted by the electron emitter. The laser emission module is used for emitting laser pulses to a to-be-detected sample, so that the to-be-detected sample reaches an excited state. And the detection module is used for detecting detection signals obtained by the laser emission module and the electron emission module acting on the to-be-detected sample. The electronic emission module, the laser emission module and the detection module are arranged to be in mutual time synchronization. According to the substance detection system and method provided by the invention, the dynamic process of different substances in different time scales can be represented, and the technical problem that the application range of a traditional system is narrow is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electron diffraction, and particularly relates to a substance detection system and method and a diagnostic device. BACKGROUND

[0002] Photon probes and electron probes have been the eyes of our research into the material world. Photon probes mainly interact with electrons in a material, while electron probes mainly interact with atomic nuclei in the material. Both of them reflect different information of the material, enabling people to understand more complete material properties. With the continuous development of accelerators, the time resolution of corresponding photon probes and electron probes is getting higher and higher. Currently, it can cover the femtosecond time scale, and gradually expand to the attosecond time scale. In a traditional electron diffraction system, a beam of ultrafast laser is divided into two beams. One beam of ultrafast laser is used as pump light, and the internal change process of the sample occurs in the picosecond to femtosecond time scale. The other beam of ultrafast laser is used to bombard an electron gun to generate photoelectrons. The photoelectrons interact with the sample after excitation, so as to realize the research on the dynamic process of the sample.

[0003] However, the traditional electron diffraction system based on the nanosecond to femtosecond time scale can only divide a beam of ultrafast laser into two beams to form pump light and probe light to study the material whose dynamic process occurs in the nanosecond to femtosecond time scale. The material whose dynamic process occurs in other time scales cannot be detected and studied, which leads to the narrow application range of the traditional system. SUMMARY

[0004] The present application aims to provide a substance detection system, method and diagnostic device, and aims to solve the technical problem of the narrow application range of the traditional system.

[0005] The first aspect of the present application provides a substance detection system, comprising:

[0006] An electron emission module comprising an electron emitter and a grid, the electron emission module being configured to emit an electron pulse to an excited-state sample to be detected, the grid being arranged at the periphery of the electron emitter and configured to regulate an electron beam emitted by the electron emitter;

[0007] A laser emission module configured to emit a laser pulse to the sample to be detected, so that the sample to be detected reaches an excited state;

[0008] A detection module configured to detect a detection signal obtained after the sample to be detected is acted on by the laser emission module and the electron emission module;

[0009] The electron emission module, the laser emission module and the detection module are arranged to be time-synchronized with each other.

[0010] In one embodiment, the electron emission module further comprises:

[0011] a power supply, connected with the electron emitter and the grid, for supplying power to the electron emitter and the grid.

[0012] In one embodiment, the laser emission module further comprises:

[0013] a laser, for emitting laser pulses to the sample to be detected;

[0014] a light path adjustment module, arranged between the laser and the sample to be detected, for adjusting the light path of the laser pulses so that the laser pulses reach the sample to be detected.

[0015] In one embodiment, the detection module comprises:

[0016] a signal conversion module, arranged between the detector and the sample to be detected, for converting the electron diffraction signals excited by the sample to be detected by the laser emission module and the electron emission module into optical detection signals;

[0017] the detector is configured to detect the optical detection signals.

[0018] In one embodiment, the detection module further comprises:

[0019] a detection light adjustment module, arranged between the signal conversion module and the detector, for adjusting the light path and field of view of the optical detection signals so that the optical detection signals reach the detector.

[0020] In one embodiment, the substance detection system further comprises:

[0021] a beam spot adjustment module, arranged between the grid and the sample to be detected, for adjusting the beam spot size of the electron pulses emitted by the grid.

[0022] In one embodiment, the substance detection system further comprises:

[0023] a housing, enclosing a vacuum chamber;

[0024] In the vacuum chamber, the electron pulses emitted by the electron emission module and the laser pulses emitted by the laser emission module act on the sample to be detected to obtain detection signals.

[0025] In one embodiment, the substance detection system further comprises:

[0026] a magnetic control module, arranged outside the housing, for adjusting the beam current of the electron pulses emitted by the grid;

[0027] The magnetic control module is time-synchronized with the electron emission module, the laser emission module, and the detection module.

[0028] In one embodiment, the magnetic control module comprises:

[0029] A magnetic control power supply for powering the magnetic control module;

[0030] A beam current adjustment device connected to the magnetic control power supply, the beam current adjustment device being arranged outside the vacuum chamber formed by the shell, and the beam current adjustment device being arranged between the electron emission module and the sample to be detected, the beam current adjustment device being used to adjust the transmission track of the electron pulse under the driving of the magnetic control power supply.

[0031] The present application provides a substance detection method, the method comprising:

[0032] The laser emission module emits a laser pulse to the sample to be detected to excite the sample to be detected to an excited state;

[0033] The electron emission module emits an electron pulse to the sample to be detected in the excited state, the electron pulse being generated according to the cooperation of the electron emitter and the grid in the electron emission module;

[0034] The detection module detects a detection signal formed after the electron pulse is emitted to the sample to be detected in the excited state;

[0035] The electron emission module, the laser emission module, and the detection module are time-synchronized.

[0036] In one embodiment, the electron emission module comprises a power supply, and the step of generating the electron pulse according to the cooperation of the electron emitter and the grid in the electron emission module comprises:

[0037] The voltage switching signal of the grid is controlled by the power supply; the voltage switching signal is determined according to the delay parameter and the pulse width parameter of the electron pulse required to be sent to the sample to be detected;

[0038] The switching time and the switching state of the grid are controlled according to the voltage switching signal to obtain the electron pulse subjected to delay regulation and pulse width regulation.

[0039] In one embodiment, before the step of controlling the voltage switching signal of the grid by the power supply, the method further comprises:

[0040] The delay parameter and the pulse width parameter required for detecting the dynamic evolution process of the sample to be detected are determined.

[0041] In one embodiment, after the step of controlling the switching time and switching state of the gate according to the voltage switching signal to obtain an electronic pulse with time delay regulation and pulse width regulation, the method further comprises:

[0042] emitting the electronic pulse to the sample in the excited state to be detected through the gate;

[0043] detecting a detection signal obtained after the electronic pulse acts on the sample in the excited state to be detected through the detection module;

[0044] obtaining a dynamic evolution process of the sample to be detected according to the detection signal.

[0045] In one embodiment, the detection module comprises a signal conversion module and a detector, and the step of detecting a detection signal obtained after the electronic pulse acts on the sample in the excited state to be detected through the detection module comprises:

[0046] converting an electron diffraction signal obtained by the interaction between the electronic pulse and the sample in the excited state to be detected into an optical detection signal through the signal conversion module;

[0047] receiving the optical detection signal through the detector.

[0048] In one embodiment, the laser emission module comprises a laser and an optical path adjustment module, and the step of emitting a laser pulse to the sample to be detected to excite the sample to the excited state through the laser emission module comprises:

[0049] controlling the laser to emit a laser pulse to the sample to be detected according to a preset laser parameter in the laser;

[0050] adjusting the optical path of the laser pulse through the optical path adjustment module so that the laser pulse reaches the sample to be detected.

[0051] The application provides a diagnostic device comprising the substance detection system described in any one of the above embodiments.

[0052] Compared with the prior art, the embodiments of the application have the following beneficial effects:

[0053] Electrons on the surface of the electron emitter, driven by an electric field, overcome the surface potential barrier and are emitted. The grid is positioned around the electron emitter, or in the electron beam's path. When the grid's potential is lower than the electron emitter's (or cathode's) potential, a potential difference is created. When this potential difference is below a critical value, the electron beam cannot pass through the grid. Increasing the grid's potential relative to the cathode, causing the potential difference to exceed the critical value, allows the electron beam to pass through. By keeping the cathode voltage constant and changing the grid's potential, the electron beam's on / off state can be controlled, thus enabling switching control of the emitted electron beam. This control over the extraction and suppression of the electron source allows for modulation of the emitted electron pulses across different pulse widths and delays.

[0054] The laser emission module and electron emission module are time-synchronized, enabling time delay between laser and electron pulses. The laser pulse emitted by the laser emission module is transmitted to the sample to be detected, bombarding it and causing structural changes that lead to an excited state. This covers the dynamic processes of the sample at different timescales. The detection signal generated by the interaction between the electron pulse (controlled by the electron emitter and grid) and the excited sample can characterize the dynamic processes of different samples at different timescales, extending beyond the nanosecond to femtosecond timescales and overcoming the narrow applicability of traditional systems. Therefore, the material detection system provided in this application can detect and study materials with dynamic processes occurring at different timescales, improving the coverage of material detection timescales and filling the gap in electron probe-based detection technologies at other timescales. Attached Figure Description

[0055] Figure 1 A schematic diagram of the material detection system provided in this application;

[0056] Figure 2 for Figure 1 The diagram shows the structural schematics of each module of the material detection system.

[0057] Figure 3 This is a schematic diagram of the structure of a material detection system provided in an embodiment of this application;

[0058] Figure 4 A schematic diagram of the structure of the material detection method provided in this application. Detailed Implementation

[0059] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0060] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0061] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0062] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0063] Please refer to Figure 1 The present application provides a substance detection system 100. The substance detection system 100 comprises an electron emission module 10, a laser emission module 30, and a detection module 40. The electron emission module 10 comprises an electron emitter 110 and a grid 120. The electron emission module 10 is used to emit an electron pulse 111 to a sample 20 to be detected in an excited state. The grid 120 is arranged at the periphery of the electron emitter 110, and the grid 120 regulates the electron beam emitted by the electron emitter 110. The laser emission module 30 is used to emit a laser pulse 311 to the sample 20 to be detected, so that the sample 20 to be detected reaches an excited state. The detection module 40 is used to detect a detection signal obtained by the sample 20 to be detected under the action of the laser emission module 30 and the electron emission module 10. The electron emission module 10, the laser emission module 30 and the detection module 40 are arranged to be mutually time-synchronized.

[0064] In this embodiment, the sample 20 to be detected can be a solid, liquid, or gaseous substance. The sample 20 undergoes kinetic processes under different conditions, such as phase transitions and chemical reactions. These kinetic processes occur on different timescales for different substances. The electron emitter 110 includes a hot cathode or a cold cathode. A hot cathode includes a spiral filament or a flat cathode. A cold cathode includes a phototube, a Zener diode, a neon tube, etc. Electrons on the surface of the electron emitter 110 are driven by an electric field, overcome the surface potential barrier, and are emitted from the electron emitter 110. The gate 120 is disposed around the electron emitter 110, or in the electron beam transmission path. When the potential of the gate 120 is lower than the potential of the cathode, a potential difference is formed. When the potential difference between the gate 120 and the cathode is lower than a critical value, the electron beam cannot pass through the gate 120. When the potential of the gate 120 relative to the cathode is increased, causing the potential difference between the gate 120 and the cathode to exceed the critical value, the electron beam can pass through the gate 120. By keeping the cathode voltage constant and changing the potential of the gate 120, the electron beam can be switched on and off, thereby controlling the electron beam emitted by the electron emitter 110, controlling the extraction and suppression of the electron source, and realizing the regulation of the electron pulse 111 emitted by the electron emitter 110 in different pulse width dimensions and different delay dimensions.

[0065] The electron emission module 10, laser emission module 30, and detection module 40 are configured to synchronize their times. This can also be understood as time synchronization control of the electron emission module 10, laser emission module 30, and detection module 40, ensuring that multiple modules maintain time consistency and operate sequentially according to a set order or logic. In one embodiment, the electron emission module 10, laser emission module 30, and detection module 40 are connected to a synchronization controller to uniformly send trigger signals, ensuring that each module starts or performs corresponding actions simultaneously. Alternatively, a high-precision clock module can be used to provide a time reference for the electron emission module 10, laser emission module 30, and detection module 40, and periodically calibrated to ensure time consistency. Alternatively, the trigger time and sequence of the electron emission module 10, laser emission module 30, and detection module 40 can be precisely set in the control software, with real-time monitoring and adjustment.

[0066] The laser emission module 30 and the electron emission module 10 are time-synchronized, enabling a time delay between the laser pulse 311 and the electron pulse 111. The laser pulse 311 emitted by the laser emission module 30 is transmitted to the sample 20 to be tested, bombarding it and causing structural changes that lead to an excited state. This process covers the dynamic processes of the sample 20 at different time scales. In the dynamic process of the sample 20, the excited state can be understood as the particles (such as atoms and molecules) absorbing energy (such as photon energy) and being in a state with energy higher than their ground state. The sample 20 in the excited state has a specific electron configuration and energy level, reflecting its dynamic behaviors such as motion, energy transfer, reaction rate, particle migration, and transformation. Examples include the internal particle motion patterns of the sample 20, such as molecular diffusion and thermal motion, or the conversion process and rate changes from reactants to products in a chemical reaction.

[0067] The detection signal generated by the interaction between the electron pulse 111, controlled by the electron emitter 110 and the gate 120, and the excited sample 20 can characterize the dynamic processes of different samples 20 occurring at different time scales. This avoids the limitation of studying matter on nanosecond to femtosecond time scales, thus solving the technical problem of the narrow applicability of traditional systems. Therefore, the material detection system 100 provided in this application can detect and study matter whose dynamic processes occur at different time scales, improving the coverage of the time scale of material detection and filling the gap in electron probe-based detection technology at other time scales.

[0068] In one embodiment, the electron emission module 10 further includes a power supply 130. The power supply 130 is connected to the electron transmitter 110 and the gate 120 respectively, and is used to provide voltage signals to the electron transmitter 110 and the gate 120.

[0069] In this embodiment, the power supply 130 provides a voltage signal and can be a high-voltage power supply. Driven by the voltage signal, electrons on the surface of the electron emitter 110 are driven by an electric field, overcoming the surface potential barrier and emitted from the electron emitter 110. The electron emitter 110 includes a hot cathode or a cold cathode. The cathode voltage remains constant. Driven by the voltage signal output from the power supply 130, the potential of the gate 120 is changed, controlling the on / off state of the electron beam to form a single electron pulse 111. By controlling the switching speed of the gate 120 through the voltage signal output from the power supply 130, electron pulses 111 with pulse widths of different time scales can be obtained. The pulse width t2 of a single electron pulse 111 can reach different time scales such as microseconds or nanoseconds. Each time the voltage signal output from the power supply 130 controls the switching delay of the gate 120, a single electron pulse 111 with a time delay relative to the laser pulse 311 can be obtained. Furthermore, the delay between multiple acquired individual electron pulses 111 can be controlled by the voltage signal output from the power supply 130 to adjust the switching delay of the gate 120, allowing the delay between multiple acquired individual electron pulses 111 to reach different time scales. The delay t1 between multiple electron pulses 111 can reach different time scales such as microseconds and nanoseconds. Thus, different types of electron pulses 111 formed by the gate 120 can detect substances whose dynamic processes occur within different time scales, improving the coverage of the time scale of substance detection and solving the technical problem of the narrow applicability of traditional electron diffraction systems.

[0070] In one embodiment, the dynamic processes of matter in the macroscopic world, such as the motion of macromolecules in solution, the orientation of solid polymers, and the spin and vibration of biological macromolecules (proteins, DNA), typically occur within a timescale ranging from 10 nanoseconds to 1 millisecond. The sample to be detected 20 is a substance whose dynamic processes occur within a timescale ranging from 10 nanoseconds to 1 millisecond; it can also be understood that the internal changes in the sample to be detected 20 occur within a timescale ranging from 10 nanoseconds to 1 millisecond.

[0071] Driven by the voltage signal output from power supply 130, the voltage of gate 120 can be controlled to vary within 100V. Under the drive of the voltage signal, gate 120 modulates the electron beam emitted by electron emitter 110, forming electron pulses 111 with charge quantities ranging from picocoulombs (pC) to millicoulombs (mC). By controlling the voltage of gate 120 through power supply 130, the pulse width of a single electron pulse 111 can reach the microsecond level, and the delay between multiple electron pulses 111 can also reach the microsecond level. This enables the study of the dynamic processes of matter within a timescale of 10 nanoseconds to 1 millisecond, filling the gap in electron probe-based pump detection technology on the microsecond timescale.

[0072] Please see Figure 2 In one embodiment, the laser emitting module 30 further includes a laser 310 and an optical path adjustment module 320. The laser 310 is used to emit laser pulses 311 toward the sample 20 to be tested. The optical path adjustment module 320 is disposed between the laser 310 and the sample 20 to be tested, and is used to adjust the optical path of the laser pulses 311 emitted by the laser 310 so that the laser pulses 311 reach the sample 20 to be tested.

[0073] In this embodiment, laser pulse 311 can be generated by modulating the operating parameters of laser 310, such as current, voltage, or other control signals. The optical path adjustment module 320 is disposed between laser 310 and the sample 20 to be detected. This can also be understood as the optical path adjustment module 320 being disposed on the optical path of the laser pulse 311 emitted by laser 310, to adjust the optical path of laser pulse 311 and guide it onto the sample 20 to be detected. Furthermore, by adjusting the optical path of laser pulse 311 through the optical path adjustment module 320, the positions of the various components in the material detection system 100 can be made more compact, reducing the size of the material detection system 100 and making it more portable.

[0074] In one embodiment, the optical path adjustment module 320 includes at least one reflector. The reflector changes the propagation direction of the laser pulse 311. The reflector can be a planar reflector or a spherical reflector.

[0075] In one embodiment, laser 310 emits laser pulse 311. The pulse width of laser pulse 311 is t3, which is less than or equal to the pulse width t2 of electron pulse 111. The time resolution of the matter detection system 100 can be expressed as:

[0076]

[0077] Here, t4 represents the time jitter of the delay between electronic pulse 111 and laser pulse 311. It can also be understood as the error between the actual delay and the theoretical delay. For example, theoretically, the delay is set to 10 microseconds (µs). However, in actual operation, during the first detection, an electronic pulse 111 is emitted with a delay of 10.1 microseconds (µs), and during the second detection, it is emitted with a delay of 0.9 microseconds (µs). Therefore, the time jitter t4 corresponding to the delay is 0.1 microseconds (µs). The time jitter t4 corresponding to the delay is much smaller than the pulse width t2 of electronic pulse 111.

[0078] By controlling the time-level jitter t4 of the delay, the pulse width t2 of a single electronic pulse 111, and the pulse width t3 of the laser pulse 311, the time resolution of the material detection system 100 can be located at different time levels, such as microseconds and nanoseconds. The laser 310 and the power supply 130 are time-synchronized. The laser pulse 311 emitted by the laser 310 bombards the sample 20 to be detected, causing the sample 20 to reach an excited state. By controlling the delay of the electron pulse 111 emitted by the gate 120 relative to the laser pulse 311 through the power supply 130, the complete dynamic process of the sample 20 to be detected is characterized and then detected by the detection module 40.

[0079] In one embodiment, the detection module 40 includes a signal conversion module 410 and a detector 420. The signal conversion module 410 is disposed between the detector 420 and the sample 20 to be detected. The signal conversion module 410 is used to convert the electron diffraction signal obtained by the laser emission module 30 and the electron emission module 10 from the sample 20 to be detected into a photodetector signal. The detector 420 is used to detect the photodetector signal converted by the signal conversion module 410.

[0080] In this embodiment, the signal conversion module 410 includes a phosphorescent screen or a fluorescent screen, capable of converting electrical signals into optical signals. The detector 420 includes an imaging plate, a scintillator CCD camera, or a direct electron detection camera, capable of receiving optical detection signals and forming diffraction pattern images. The signal conversion module 410 is disposed between the detector 420 and the sample 20 to be detected, which can be understood as being disposed in the transmission path of the electron diffraction signal obtained by exciting the sample 20. The laser pulse 311 emitted by the laser emission module 30 bombards the sample 20 to be detected, causing the sample 20 to reach an excited state. The electron pulse 111 emitted by the electron emission module 10 interacts with the sample 20 in the excited state to form a corresponding electron diffraction signal, characterizing the dynamic process of the sample 20. The electron diffraction signal reaches the signal conversion module 410. The signal conversion module 410 converts the electron diffraction signal into an optical detection signal. The optical detection signal is received and detected by the detector 420. The dynamic process of the sample 20 to be detected is displayed on the detector 420 in the form of diffraction spots, forming a corresponding diffraction spot image. Through the signal conversion module 410 and the detector 420, the signal carrying the sample characteristic information generated by the interaction between the electron pulse 111 and the sample 20 to be detected in the excited state can be presented, thereby enabling better observation and analysis of transient structural information at different times.

[0081] In one embodiment, the detection module 40 further includes a detection light adjustment module 430. The detection light adjustment module 430 is disposed between the signal conversion module 410 and the detector 420, and is used to adjust the optical path and field of view of the light detection signal converted by the signal conversion module 410 so that the light detection signal reaches the detector 420.

[0082] In this embodiment, the probe light adjustment module 430 is disposed between the signal conversion module 410 and the detector 420. It can be understood that the probe light adjustment module 430 is positioned in the transmission path of the light detection signal formed after conversion by the signal conversion module 410, used to adjust the optical path and field of view of the light detection signal, ensuring that the light detection signal accurately reaches the detector 420. The probe light adjustment module 430 includes an optical path guiding module 431 and a field of view adjustment module 432. The optical path guiding module 431 includes at least one reflector. By changing the propagation direction of the light detection signal through the reflector, an upright and equal-sized virtual image can be formed. The reflector can be a plane reflector or a spherical reflector. The field of view adjustment module 432 includes at least one lens, capable of focusing and / or collimating the light detection signal. The optical path guiding module 431 is disposed between the signal conversion module 410 and the field of view adjustment module 432. The field of view adjustment module 432 is disposed between the optical path guiding module 431 and the detector 420. The optical path guiding module 431 guides the optical detection signal, converted by the signal conversion module 410, to reach the detector 420. The field-of-view adjustment module 432 focuses and / or collimates the optical detection signal guided by the optical path guiding module 431, converting the large-field-of-view optical detection signal into a small-field-of-view optical detection signal, which is then projected onto the sensor chip of the detector 420. Furthermore, by adjusting the optical path of the optical detection signal through the detection light adjustment module 430, the positions of the various components in the matter detection system 100 can be made more compact, further reducing the size of the matter detection system 100 and making it more portable.

[0083] Please see Figure 3 The arrow A at the signal conversion module 410, the arrow B at the optical path guiding module 431, and the arrow C at the detector 420 represent the three imaging processes of the photodetector signal corresponding to the sample 20 to be detected. The optical path guiding module 431 converts the real image (arrow A) on the signal conversion module 410 into a virtual image (arrow B) of the same size. The field-of-view adjustment module 432 converts the virtual image (arrow B) into a reduced-size arrow (arrow C) and projects it onto the detector 420.

[0084] In one embodiment, the material detection system 100 further includes a beam spot adjustment module 50. The beam spot adjustment module 50 is disposed between the gate 120 and the sample 20 to be detected, and is used to adjust the beam spot size of the electron pulse 111 after the gate 120 is regulated, so that the electron pulse 111 reaches the sample 20 to be detected.

[0085] In this embodiment, the beam spot adjustment module 50 is disposed between the gate 120 and the sample 20 to be detected. This can be understood as the beam spot adjustment module 50 being positioned in the transmission path of the electron pulse 111 emitted after being controlled by the gate 120. The beam spot adjustment module 50 includes an aperture or a deflector plate. The aperture can be understood as a metal element with a small hole, capable of adjusting the lateral beam spot size of the electron pulse 111. The deflector plate can change the deflection angle of the electron pulse 111 to adjust the lateral position and size of the beam spot. The beam spot size can be understood as the diameter or radius of the light spot formed by the electron pulse 111 on a plane perpendicular to its propagation direction. The beam spot adjustment module 50 can adjust the lateral beam spot size of the electron pulse 111, allowing an electron pulse 111 of a specific size to pass through and interact with the excited-state sample 20 to form an electron diffraction signal. After the electron pulse 111 interacts with the excited-state sample 20, an electron diffraction signal is formed and received and detected by the signal conversion module 410. Furthermore, the electron diffraction signal is converted into a light detection signal by the signal conversion module 410 so that it can be detected by the detector 420.

[0086] In one embodiment, the material detection system 100 further includes a housing 60. The housing 60 surrounds and forms a vacuum chamber 610. Within the vacuum chamber 610, electron pulses 111 emitted by the electron emission module 10 and laser pulses 311 emitted by the laser emission module 30 act on the sample 20 to be detected, thereby obtaining a detection signal.

[0087] In this embodiment, the housing 60 surrounds and forms a vacuum chamber 610 to ensure that the beam of the entire device is within a vacuum range. The electron emitter 110, grid 120, electron pulse 111, beam adjustment module 50, sample 20 to be detected, signal conversion module 410, and optical path guiding module 431 are disposed within the vacuum chamber 610, so that the interaction between the electron pulse 111 and the sample 20 to be detected in the excited state occurs within the vacuum chamber 610. The vacuum chamber 610 formed by the housing 60 provides a vacuum environment for the material detection process, eliminating external interference and improving detection stability.

[0088] In one embodiment, the matter detection system 100 further includes a magnetron control module 70. The magnetron control module 70 is disposed on the outside of the housing 60 and is used to adjust the beam current of the electron pulses 111 emitted by the gate 120. The magnetron control module 70 is time-synchronized with the electron emission module 10, the laser emission module 30, and the detection module 40.

[0089] In this embodiment, the magnetron control module 70 is located outside the housing 60, which can be understood as being located outside the vacuum chamber 610, and is not in the same space as the electron emitter 110, grid 120, electron pulse 111, beam adjustment module 50, sample to be detected 20, signal conversion module 410, and optical path guidance module 431. The magnetron control module 70 is time-synchronized with the electron emission module 10, laser emission module 30, and detection module 40, enabling each module to work collaboratively on the same time base, ensuring time consistency at each node, and improving the overall efficiency and response speed of the material detection system 100. The magnetron control module 70 can flexibly adjust the beam characteristics to meet different material detection needs, thereby achieving the optimal beam state, ensuring the normal operation and efficient work of the material detection system 100, and improving the accuracy of material detection.

[0090] In one embodiment, the magnetron control module 70 includes a magnetron power supply 710 and a beam adjustment device 720. The magnetron power supply 710 supplies power to the magnetron control module 70. The beam adjustment device 720 is connected to the magnetron power supply 710. The beam adjustment device 720 is disposed outside the vacuum chamber 610 formed by the housing 60. The beam adjustment device 720 is disposed between the electron emission module 10 and the sample 20 to be detected. The beam adjustment device 720 is used to adjust the transmission track of the electron pulse 111 under the drive of the magnetron power supply 710.

[0091] In this embodiment, the magnetically controlled power supply 710 generates a magnetic field by controlling the current of the beam current adjustment device 720, thereby manipulating the electron pulse 111 through the magnetic field. The magnetically controlled power supply 710 can adjust the magnitude and direction of the current input to the beam current adjustment device 720, achieving control over parameters such as the intensity, focus, and deflection of the electron pulse 111. The beam current adjustment device 720 includes deflecting magnets or electromagnetic coils. Through the magnetically controlled power supply 710 and the beam current adjustment device 720, high-precision control of the transmission trajectory of the electron pulse 111 can be achieved. This can be flexibly adjusted according to different application scenarios, ensuring the stability and accuracy of the electron pulse 111 during transmission, so as to accurately reach the position of the sample 20 to be detected. Furthermore, through the magnetically controlled power supply 710 and the beam current adjustment device 720, the pulse width and timing jitter information of unknown electron pulses 111 can also be measured.

[0092] In the entire matter detection system 100, the magnetically controlled power supply 710, the power supply 130, the laser 310, and the detector 420 maintain time synchronization. Their relative delays can be adjusted on the same time base, enabling all modules in the system to work collaboratively on the same time base, ensuring time consistency at each node, and improving the overall efficiency and response speed of the matter detection system 100. By controlling the relative delays of the laser 310, the power supply 130, and the magnetically controlled power supply 710, the complete dynamic process of the sample 20 to be detected can be studied.

[0093] Please see Figure 4 This application provides a method for detecting a substance, the method comprising:

[0094] S10, laser pulse 311 is emitted from laser emission module 30 to the sample 20 to be detected, so as to excite the sample 20 to be detected to an excited state;

[0095] S20, an electron pulse 111 is emitted to the excited-state sample 20 through the electron emission module 10. The electron pulse 111 is generated according to the cooperation of the electron emitter 110 and the gate 120 in the electron emission module 10.

[0096] S30, the detection module 40 detects the detection signal formed after the electron pulse 111 is emitted to the excited state of the sample 20 to be detected;

[0097] Among them, the electron emission module 10, the laser emission module 30 and the detection module 40 are kept in time synchronization.

[0098] In this embodiment, the laser emission module 30 and the electron emission module 10 are time-synchronized, which can achieve a relative delay between the laser pulse 311 and the electron pulse 111. The laser pulse 311 emitted by the laser emission module 30 bombards the sample 20 to be detected, causing the structure of the sample 20 to change and reach an excited state.

[0099] Electron pulse 111 is generated by the electron emitter 110 and gate 120 in the electron emission module 10. When the potential of gate 120 is lower than the potential of electron emitter 110 (which can also be understood as cathode), a potential difference is formed. When the potential difference between gate 120 and cathode is lower than a critical value, the electron beam cannot pass through gate 120. When the potential of gate 120 relative to cathode is increased, so that the potential difference between gate 120 and cathode exceeds the critical value, the electron beam can pass through gate 120. By keeping the voltage of electron emitter 110 constant and changing the potential of gate 120, the on / off state of the electron beam can be controlled, thereby controlling the electron beam emitted by electron emitter 110, controlling the extraction and suppression of the electron source, and realizing the modulation of electron pulse 111 emitted by electron emitter 110 in different pulse width and delay dimensions. Therefore, the detection signal generated by the interaction between the electron pulse 111, controlled by the electron emitter 110 and the gate 120, and the excited sample 20 can characterize the dynamic processes of different samples 20 occurring at different time scales. This avoids the limitation of studying matter on nanosecond to femtosecond time scales, thus solving the technical problem of the narrow applicability of traditional systems. Therefore, the matter detection method provided in this application can detect and study matter whose dynamic processes occur at different time scales, improving the coverage of the time scale of matter detection and filling the gap in electron probe-based detection technology at other time scales.

[0100] In one embodiment, the step of generating the electronic pulse 111 according to the interaction between the electron emitter 110 and the gate 120 in the electron emission module 10 in S20 includes:

[0101] S210, determine the delay parameters and pulse width parameters required to detect the dynamic evolution process of the sample 20 to be detected.

[0102] In this embodiment, the delay parameter and pulse width parameter can be determined based on the material properties of the sample 20 to be detected. The kinetic process of some samples 20 to be detected occurs within microseconds, for example, the entire kinetic process occurs within hundreds of microseconds. The kinetic process of some samples 20 to be detected occurs within nanoseconds, for example, the entire kinetic process occurs within hundreds of nanoseconds. And so on, different samples 20 to be detected correspond to kinetic processes of different durations. Based on the duration of the kinetic process of the sample 20 to be detected, the delay parameter and pulse width parameter required to detect the kinetic evolution of the sample 20 to be detected are determined. This allows for the setting of multiple electronic pulses 111 with different delays, or electronic pulses 111 with different pulse widths.

[0103] In one embodiment, the sample 20 to be detected is a substance whose kinetic process occurs on a timescale ranging from 10 nanoseconds to 1 millisecond. Based on the kinetic characteristics of the sample 20, the delay required to detect the kinetic evolution of the sample 20 is determined to be on the order of microseconds, and the pulse width is also on the order of microseconds. Furthermore, the number of delays required is determined based on the occurrence time and delay value of the kinetic process of the sample 20.

[0104] In one embodiment, the electron emission module 10 includes a power supply 130. In S20, the step of generating the electron pulse 111 based on the interaction between the electron emitter 110 and the gate 120 in the electron emission module 10 includes:

[0105] S220, the voltage switching signal of the gate 120 is controlled by the power supply 130; the voltage switching signal is determined by the delay parameter and pulse width parameter of the electronic pulse 111 sent to the sample 20 to be detected as needed;

[0106] S230 controls the switching time and switching state of the gate 120 according to the voltage switching signal to obtain an electronic pulse 111 that has been delayed and pulse width regulated.

[0107] In this embodiment, to detect the dynamic evolution of the sample 20, it is necessary to obtain diffraction patterns of the interaction between the electron pulse 111 and the sample 20 in the excited state under different time delays. The delay parameters and pulse width parameters can be determined according to the material properties of the sample 20. The occurrence time of the dynamic process corresponding to different samples 20 is different, thus requiring different delay parameters and pulse width parameters for the electron pulse 111, which correspond to different voltage switching signals. The power supply 130, laser 310, and detector 420 are kept in time synchronization. The relative delay between the power supply 130 and laser 310 can be adjusted on the same time base. The power supply 130 controls the voltage switching signal of the gate 120 according to the delay parameters and pulse width parameters of the electron pulse 111 sent to the sample 20 as needed. According to the voltage switching signal output by the power supply 130, the potential of the gate 120 is changed, controlling the switching time and switching state of the gate 120. Controlling the switching time of the gate 120 based on the voltage switching signal can be understood as controlling the switching speed of the gate 120, resulting in single electronic pulses 111 with pulse widths of different time scales. Therefore, the pulse width t2 of a single electronic pulse 111 can reach different time scales such as microseconds and nanoseconds. During each detection, the delay of a single electronic pulse 111 relative to the laser pulse 311 can be controlled by the voltage switching signal to control the switching state of the gate 120 (which can also be understood as controlling the switching delay of the gate 120), achieving different time scales. This allows the delay between multiple single electronic pulses 111 to reach different time scales. Thus, the delay t1 between multiple electronic pulses 111 can reach different time scales such as microseconds and nanoseconds. Therefore, through the method steps provided in this embodiment, different types of electronic pulses 111 can be generated for different samples 20 to be detected, enabling the detection of substances whose dynamic processes occur within different time scales, improving the coverage of the material detection timescale, and solving the technical problem of the narrow applicability of traditional methods.

[0108] In one embodiment, S230, after the step of controlling the switching time and switching state of the gate 120 according to the voltage switching signal to obtain the electron pulse 111 after delay modulation and pulse width modulation, the matter detection method further includes:

[0109] S410, an electron pulse 111 is emitted to the excited-state sample 20 through the gate 120;

[0110] S420, the detection signal obtained by the detection module 40 after the electronic pulse 111 acts on the excited state of the sample 20 to be detected;

[0111] S430, the dynamic evolution process of the sample 20 to be detected is obtained based on the detection signal.

[0112] In this embodiment, different samples 20 to be detected exhibit dynamic processes with different time scales. Based on the duration of the dynamic process of the sample 20 to be detected, the required delay value and number of delays for completing the dynamic evolution process of the sample 20 to be detected can be determined. S410 and S420 can achieve one acquisition of a detection signal corresponding to one electron pulse 111. By repeating S410 and S420 within the time required to complete the dynamic process of the sample 20 to be detected, multiple acquisitions of detection signals at each delay can be achieved until the entire detection process is completed. Then, the dynamic evolution process of the sample 20 to be detected can be obtained based on the acquired detection signals. In one embodiment, the dynamic evolution process of the sample 20 to be detected is as follows:

[0113] A first laser pulse 311 is emitted from the laser emission module 30 towards the sample 20 to excite it to an excited state. A first electron pulse 111 is then emitted from the gate 120 towards the excited sample 20. The first electron pulse 111 has a first delay relative to the first laser pulse 311. After the first electron pulse 111 interacts with the excited sample 20, a first detection signal is formed. This first detection signal is detected by the detection module 40, which displays the dynamic process of the sample 20 under the first delay as a diffraction pattern, obtaining a diffraction pattern image and completing one acquisition process. Based on this, multiple diffraction pattern images under the first delay are repeatedly acquired and superimposed to obtain a high signal-to-noise ratio diffraction pattern signal.

[0114] After completing the acquisition under the first delay, signal acquisition under the second delay is performed. A second laser pulse 311 is emitted from the laser emission module 30 towards the sample 20 to excite it to an excited state. A second electron pulse 111 is emitted from the gate 120 towards the excited sample 20. The second electron pulse 111 has a second delay relative to the second laser pulse 311. After the second electron pulse 111 interacts with the excited sample 20, a second detection signal is formed. This second detection signal is detected by the detection module 40, which displays the dynamic process of the sample 20 under the second delay as a diffraction pattern, obtaining a diffraction pattern image, thus completing one acquisition process. Based on this, multiple diffraction pattern images under the second delay are repeatedly acquired and superimposed to obtain a high signal-to-noise ratio diffraction pattern signal.

[0115] After completing the acquisition under the second delay, signal acquisition under the third delay is performed. A third laser pulse 311 is emitted towards the sample 20 to excite it to an excited state. A third electron pulse 111 is emitted towards the excited sample 20 through the gate 120. The third electron pulse 111 has a third delay relative to the third laser pulse 311. After interacting with the excited sample 20, the third electron pulse 111 forms a third detection signal. This third detection signal is detected by the detection module 40, which displays the dynamic process of the sample 20 under the third delay as a diffraction pattern, obtaining a diffraction pattern image, thus completing one acquisition process. Based on this, multiple diffraction pattern images under the third delay are repeatedly acquired and superimposed to obtain a high signal-to-noise ratio diffraction pattern signal.

[0116] Repeat the above steps at different delays, such as the fourth, fifth, and sixth delays, until the acquisition of a complete dynamic evolution process of the sample 20 to be detected is completed.

[0117] In one embodiment, the detection module 40 includes a signal conversion module 410 and a detector 420. S30, the step of detecting the detection signal formed after the electron pulse 111 is emitted to the excited state of the sample 20 by the detection module 40, includes:

[0118] S310, the electron diffraction signal obtained by the interaction of the electron pulse 111 with the excited state of the sample to be detected 20 is converted into a light detection signal by the signal conversion module 410;

[0119] S320 receives optical detection signals through detector 420.

[0120] In this embodiment, the electron pulse 111 emitted by the electron emission module 10 interacts with the sample 20 in the excited state to form a corresponding electron diffraction signal, characterizing the dynamic process of the sample 20. The electron diffraction signal is received by the signal conversion module 410 and converted into a photodetector signal. The photodetector signal is received by the detector 420, and the dynamic process of the sample 20 is displayed on the detector 420 in the form of diffraction spots, forming a corresponding diffraction spot image. Through the steps provided in this embodiment, the signal carrying sample feature information generated by the interaction between the electron pulse 111 and the sample 20 in the excited state can be presented, thereby enabling better observation and analysis of transient structural information at different times.

[0121] In one embodiment, the laser emitting module 30 includes a laser 310 and an optical path adjustment module 320. S10, the step of emitting a laser pulse 311 to the sample 20 to be detected via the laser emitting module 30 to excite the sample to an excited state, includes:

[0122] S110, according to the preset laser parameters in the laser 310, control the laser 310 to emit laser pulses 311 toward the sample 20 to be detected;

[0123] S120, the optical path of the laser pulse 311 is adjusted by the optical path adjustment module 320 so that the laser pulse 311 reaches the sample 20 to be detected.

[0124] In this embodiment, the preset laser parameters include current, voltage, or other control signals. Based on the preset laser parameters in the laser 310, the laser 310 is controlled to generate laser pulses 311, which are emitted to the sample 20 to be detected, bombarding the sample 20 and causing it to reach an excited state. By adjusting the optical path of the laser pulses 311 through the optical path adjustment module 320, the laser pulses 311 can be accurately guided to the sample 20 to be detected, thereby ensuring the detection accuracy of the material detection method.

[0125] This application provides a diagnostic device, including a substance detection system 100 of any of the above embodiments.

[0126] In this embodiment, the diagnostic device includes the material detection system 100 of any of the above embodiments, which can be used to study dynamic processes at different time scales. The diagnostic device can be an electron diffractometer, a transmission electron microscope, etc. An electron diffractometer analyzes information such as the crystal structure and lattice parameters of a substance by measuring the diffraction pattern of an electron beam on a sample. A transmission electron microscope uses a high-energy electron beam to penetrate the sample and studies the microstructure of the substance by imaging and analyzing the transmitted electrons. The diagnostic device provided in this application can characterize the dynamic processes of different samples under test at different time scales, enabling the study of the dynamic processes of different substances, which is of great significance in research fields such as materials science, biology, and physics.

[0127] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0129] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0130] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0131] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0133] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0134] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A substance detection system, characterized in that, include: An electron emission module (10) includes an electron emitter (110) and a gate (120). The electron emission module (10) is used to emit electron pulses to the excited sample (20) to be detected. The gate (120) is disposed around the electron emitter (110) and the gate (120) controls the electron beam emitted by the electron emitter (110). The laser emitting module (30) is used to emit laser pulses to the sample to be detected (20) so that the sample to be detected (20) reaches an excited state; The detection module (40) is used to detect the detection signal obtained after the laser emission module (30) and the electron emission module (10) act on the sample (20) to be detected; The electron emission module (10), the laser emission module (30), and the detection module (40) are configured to synchronize their time.

2. The material detection system as described in claim 1, characterized in that, The electron emission module (10) also includes: A power supply (130), connected to the electron transmitter (110) and the gate (120), is used to supply power to the electron transmitter (110) and the gate (120).

3. The material detection system as described in claim 1, characterized in that, The laser emitting module (30) also includes: A laser (310) is used to emit laser pulses toward the sample (20) to be detected; An optical path adjustment module (320) is disposed between the laser (310) and the sample to be detected (20) for adjusting the optical path of the laser pulse so that the laser pulse reaches the sample to be detected (20).

4. The material detection system as described in claim 1, characterized in that, The detection module (40) includes: A signal conversion module (410) is disposed between the detector (420) and the sample to be detected (20). The signal conversion module (410) is used to convert the electron diffraction signal obtained by the laser emission module (30) and the electron emission module (10) from the sample to be detected (20) into a light detection signal. The detector (420) is used to detect the optical detection signal.

5. The material detection system as described in claim 4, characterized in that, The detection module (40) also includes: A detection light adjustment module (430) is disposed between the signal conversion module (410) and the detector (420) for adjusting the optical path and field of view of the light detection signal so that the light detection signal reaches the detector (420).

6. The material detection system as described in claim 1, characterized in that, The material detection system also includes: A beam spot adjustment module (50) is disposed between the gate (120) and the sample to be detected (20) for adjusting the beam spot size of the electron pulse emitted by the gate (120).

7. The material detection system as described in claim 1, characterized in that, The material detection system also includes: The shell (60) surrounds and forms a vacuum chamber (610); Inside the vacuum chamber (610), the electron pulses emitted by the electron emission module (10) and the laser pulses emitted by the laser emission module (30) act on the sample to be detected (20) to obtain a detection signal.

8. The material detection system as described in claim 7, characterized in that, The material detection system also includes: A magnetron control module (70) is disposed on the outside of the housing (60) and is used to adjust the beam current of the electron pulse emitted by the gate (120); The magnetic control module (70) is synchronized with the electron emission module (10), the laser emission module (30) and the detection module (40).

9. The material detection system as described in claim 8, characterized in that, The magnetic control module (70) includes: A magnetic power supply (710) is used to supply power to the magnetic control module (70); A beam adjustment device (720) is connected to the magnetron power supply (710). The beam adjustment device (720) is disposed outside the vacuum chamber (610) formed by the housing (60) and is disposed between the electron emission module (10) and the sample to be detected (20). The beam adjustment device (720) is used to adjust the transmission track of the electron pulse under the drive of the magnetron power supply (710).

10. A method for detecting matter, characterized in that, The method includes: A laser pulse is emitted from the laser emission module (30) toward the sample to be detected (20) to excite the sample to be detected (20) to an excited state; An electron pulse is emitted to the excited sample (20) by an electron emission module (10), and the electron pulse is generated by the electron emitter (110) and the gate (120) in the electron emission module (10). The detection module (40) detects the detection signal formed after the electron pulse is emitted to the excited state of the sample (20); The electron emission module (10), the laser emission module (30), and the detection module (40) are kept in time synchronization.

11. The material detection method as described in claim 10, characterized in that, The electron emission module (10) includes a power supply (130), and the electron pulse is generated according to the steps of the electron emitter (110) and gate (120) in the electron emission module (10) including: The voltage switching signal of the gate (120) is controlled by the power supply (130); the voltage switching signal is determined by the delay parameter and pulse width parameter of the electronic pulse sent to the sample to be detected (20) as needed; The switching time and switching state of the gate (120) are controlled according to the voltage switching signal to obtain an electronic pulse that has been delayed and pulse width modulated.

12. The material detection method as described in claim 11, characterized in that, Before the step of controlling the voltage switching signal of the gate (120) via the power supply (130), the method further includes: Determine the delay parameters and pulse width parameters required to detect the dynamic evolution of the sample (20) to be detected.

13. The material detection method as described in claim 12, characterized in that, After the step of controlling the switching time and switching state of the gate (120) according to the voltage switching signal to obtain an electronic pulse after delay modulation and pulse width modulation, the method further includes: The electron pulse is emitted through the gate (120) to the excited sample (20) to be detected; The detection module (40) detects the detection signal obtained after the electronic pulse acts on the excited state of the sample (20); The dynamic evolution process of the sample to be detected (20) is obtained based on the detection signal.

14. The material detection method as described in claim 10, characterized in that, The detection module (40) includes a signal conversion module (410) and a detector (420). The step of detecting the detection signal formed after the electron pulse is emitted to the excited state of the sample (20) through the detection module (40) includes: The signal conversion module (410) converts the electron diffraction signal obtained by the interaction between the electron pulse and the excited-state sample (20) into a light detection signal. The optical detection signal is received by the detector (420).

15. The material detection method as described in claim 10, characterized in that, The laser emitting module (30) includes a laser (310) and an optical path adjustment module (320). The step of emitting laser pulses to the sample to be detected (20) through the laser emitting module (30) to excite the sample to an excited state includes: According to the preset laser parameters in the laser (310), the laser (310) is controlled to emit laser pulses toward the sample (20) to be detected; The laser pulse is adjusted by the optical path adjustment module (320) so that the laser pulse reaches the sample to be detected (20).

16. A diagnostic device, characterized in that, The substance detection system includes any one of claims 1 to 9.

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