X-ray diode signal reconstruction method

Abstract

The application relates to an X-ray diode signal reconstruction method, which comprises the following steps: determining an electron pulse time expansion multiple function; determining an MCP gain function; obtaining an electron pulse signal output by an X-ray diode system; performing first processing on the electron pulse signal based on the electron pulse time expansion multiple function to obtain a first processing pulse signal; performing second processing on the first processing pulse signal based on the electron pulse time expansion multiple function to obtain a second processing pulse signal; and processing the second processing pulse signal according to the MCP gain function to obtain a reconstructed signal. Through the application, the influence of the inconsistency of electron pulse time expansion multiples at different slope positions of a cathode pulse and the inconsistency of MCP gains on the measurement accuracy of the X-ray diode system can be reduced, the input signal of the X-ray diode system can be accurately reconstructed, and the measurement accuracy of the X-ray diode system can be effectively improved.

Description

Technical Field

[0001] This invention relates to the technical field of laser inertial confinement fusion, and more specifically, to a method for reconstructing X-ray diode signals. Background Technology

[0002] X-ray diode (XRD) is an important diagnostic tool in Inertial Confinement Fusion (ICF) research. Traditional XRD has a temporal resolution of approximately 100 ps. However, with the advancement of ICF research, this 100 ps time-resolution XRD is insufficient to meet the detailed diagnostic requirements of certain key physical processes. Using electron pulse time-stretching technology, the temporal resolution of XRD can be improved to 10 ps.

[0003] Time broadening is achieved through electron energy diffusion. If a linear cathode pulse is used, the electron energy changes linearly, while the electron velocity changes non-linearly, resulting in a non-linear amplification of the electron beam time width. To improve the measurement accuracy of the XRD system, a curved pulse-driven microstrip cathode is needed to achieve linear amplification of the electron beam time width, ensuring that each ramp position of the cathode pulse has the same electron pulse time broadening factor. However, obtaining a cathode pulse with a perfectly suitable waveform is difficult. Time broadening also results in higher energy electrons at the beginning and lower energy electrons at the end. If an electron beam with gradually decreasing energy directly bombards a microchannel plate (MCP), the MCP gain will gradually decrease over time due to the changing electron energy, leading to a progressively lower amplitude of the anode output signal and measurement errors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an X-ray diode signal reconstruction method to address the problems existing in the prior art.

[0005] The technical solution adopted by this invention to solve its technical problem is: to construct an X-ray diode signal reconstruction method, comprising the following steps:

[0006] Determine the electronic pulse time-spanning factor function;

[0007] Determine the MCP gain function;

[0008] Acquire the electronic pulse signal output by the X-ray diode system;

[0009] The electronic pulse signal is processed once based on the electronic pulse time-spanning factor function to obtain a processed pulse signal;

[0010] The primary processed pulse signal is processed a second time based on the electronic pulse time-spanning function to obtain a secondary processed pulse signal.

[0011] The secondary processing pulse signal is processed according to the MCP gain function to obtain the reconstructed signal.

[0012] In the X-ray diode signal reconstruction method of the present invention, the step of processing the electronic pulse signal based on the electronic pulse time-spanning function to obtain a processed pulse signal includes:

[0013] The relationship between the electronic pulse time broadening and the signal incident time is obtained based on the electronic pulse time broadening factor function.

[0014] Based on the relationship between the electronic pulse time broadening and the signal incident time, determine the electronic pulse time broadening factor corresponding to the time interval between two adjacent points in the electronic pulse signal;

[0015] The electronic pulse signal is time-compressed according to the electronic pulse time-spanning factor corresponding to the time interval between the two adjacent points to obtain a time-compressed pulse signal; the time-compressed pulse signal is the first-processed pulse signal.

[0016] In the X-ray diode signal reconstruction method of the present invention, the step of compressing the electronic pulse signal according to the electronic pulse time broadening factor corresponding to the time interval between the two adjacent points to obtain the time-compressed pulse signal includes:

[0017] Divide the time interval between each two adjacent points in the electronic pulse signal by the corresponding electronic pulse time broadening factor, while keeping the corresponding ordinate unchanged, to obtain the time-compressed pulse signal.

[0018] In the X-ray diode signal reconstruction method of the present invention, the step of performing secondary processing on the primary processed pulse signal based on the electron pulse time-spanning function to obtain the secondary processed pulse signal includes:

[0019] The relationship between the electronic pulse time broadening and the signal incident time is obtained based on the electronic pulse time broadening factor function.

[0020] Based on the relationship between the electronic pulse time broadening and the signal incident time, determine the electronic pulse time broadening factor corresponding to the time interval between two adjacent points in the electronic pulse signal;

[0021] The primary processed pulse signal is processed a second time based on the electronic pulse time broadening factor corresponding to the time interval between the two adjacent points to obtain the secondary processed pulse signal.

[0022] In the X-ray diode signal reconstruction method of the present invention, the step of performing secondary processing on the primary processed pulse signal according to the electron pulse time broadening factor corresponding to the time interval between the two adjacent points to obtain the secondary processed pulse signal includes:

[0023] The voltage value at each point in the primary processing pulse signal is multiplied by the electronic pulse time stretching factor to obtain the secondary processing pulse signal.

[0024] In the X-ray diode signal reconstruction method of the present invention, the step of processing the secondary processing pulse signal according to the MCP gain function to obtain the reconstructed signal includes:

[0025] The relationship between MCP gain and signal incident time is determined based on the MCP gain function.

[0026] Based on the relationship between the MCP gain and the signal incident time, determine the MCP gain corresponding to the voltage value at each point of the electronic pulse signal;

[0027] The reconstructed signal is obtained by dividing the voltage value of each point of the secondary processed pulse signal by the MCP gain corresponding to the voltage value of each point.

[0028] In the X-ray diode signal reconstruction method of the present invention, determining the electron pulse time-spanning factor function includes:

[0029] The relationship between electron pulse time broadening and signal incident time is obtained by using fiber optic method; the relationship between electron pulse time broadening and signal incident time is the electron pulse time broadening factor function.

[0030] In the X-ray diode signal reconstruction method of the present invention, the MCP gain function is determined by measurement using a first measurement method or a second measurement method;

[0031] The first measurement method includes: using fiber optic bundle method and fluorescent screen to measure and obtain the relationship between MCP gain and signal incident time;

[0032] The second measurement method includes:

[0033] The relationship between MCP gain and electron energy was obtained by measuring the change in electron energy.

[0034] To determine the relationship between electron energy and signal incident time;

[0035] The relationship between MCP gain and signal incident time is determined based on the relationship between MCP gain and electron energy and the relationship between electron energy and signal incident time.

[0036] The relationship between the MCP gain and the signal incident time is the MCP gain function.

[0037] In the X-ray diode signal reconstruction method of the present invention, the following steps are performed before the electronic pulse signal is processed once:

[0038] Determine the MCP impulse response function;

[0039] Determine the anode response function;

[0040] The electronic pulse signal is sequentially deconvolved with the anode response function and the MCP pulse response function.

[0041] In the X-ray diode signal reconstruction method of the present invention, the MCP pulse response function is obtained by femtosecond laser and scanning imaging measurement;

[0042] The anode response function is obtained by directly irradiating the anode electron detector with a femtosecond laser and then acquiring and processing the pulse signal.

[0043] The X-ray diode signal reconstruction method of the present invention has the following beneficial effects: The X-ray diode signal reconstruction method includes the following steps: determining the electron pulse time-spanning factor function; determining the MCP gain function; acquiring the electron pulse signal output by the X-ray diode system; performing a first-stage processing on the electron pulse signal based on the electron pulse time-spanning factor function to obtain a first-stage processed pulse signal; performing a second-stage processing on the first-stage processed pulse signal based on the electron pulse time-spanning factor function to obtain a second-stage processed pulse signal; and processing the second-stage processed pulse signal according to the MCP gain function to obtain a reconstructed signal. This invention can reduce the impact of inconsistent electron pulse time-spanning factors and inconsistent MCP gains at different slope positions of the cathode pulse on the measurement accuracy of the X-ray diode system, achieving accurate reconstruction of the input signal of the X-ray diode system and effectively improving the measurement accuracy of the X-ray diode system. Attached Figure Description

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0045] Figure 1 This is a flowchart illustrating an embodiment of the X-ray diode signal reconstruction method provided by the present invention;

[0046] Figure 2 This is a schematic diagram of input signal reconstruction based on time stretching factor and MCP gain provided by the present invention;

[0047] Figure 3 This is a schematic diagram of the electronic pulse time-stretching ratio measuring device provided by the present invention;

[0048] Figure 4 This is a flowchart illustrating Embodiment 2 of the X-ray diode signal reconstruction method provided by the present invention;

[0049] Figure 5 This is a schematic diagram of measuring the MCP pulse response using femtosecond laser and scanning imaging provided by the present invention;

[0050] Figure 6 This invention provides the system output electrical pulse waveform when using electronic pulse time stretching technology;

[0051] Figure 7 This is a schematic diagram of the cathode pulse waveform and the time-spanning factor function D(t) provided by the present invention for time stretching;

[0052] Figure 8 This is a schematic diagram illustrating the relationship between the normalized MCP gain and electron energy provided by the present invention;

[0053] Figure 9 This is a schematic diagram of the MCP gain function G(t) provided by the present invention;

[0054] Figure 10 This is a waveform diagram of the reconstructed signal provided by the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] To improve the measurement accuracy of X-ray diode systems (hereinafter referred to as XRD systems), this invention reconstructs the input signal by utilizing the electronic pulse signal detected by the system, the electronic pulse time-spanning function D(t), and the MCP gain function G(t) to reconstruct an almost undistorted input optical signal.

[0057] In a preferred embodiment, such as Figure 1 As shown, the X-ray diode signal reconstruction method includes the following steps:

[0058] Step S10: Determine the electronic pulse time-stretching function.

[0059] Optionally, in this embodiment of the invention, determining the electron pulse time-spanning factor function includes: measuring using a fiber optic method to obtain the relationship between the electron pulse time-spanning and the signal incident time; the relationship between the electron pulse time-spanning and the signal incident time is the electron pulse time-spanning factor function. In this embodiment of the invention, the electron pulse time-spanning factor function D(t) is the relationship between the electron pulse time-spanning factor and the signal incident time, which is obtained by measuring when the incident light is synchronously at different ramp positions of the cathode pulse. This invention uses a fiber optic method to measure the electron pulse time-spanning factor. The measuring device is as follows: Figure 3 As shown.

[0060] like Figure 3 As shown, the laser signal generated by the laser is split into two beams by BS1 (beam splitter). One beam, ultraviolet light, is reflected by total internal reflection mirror M2 and then transmitted to neutral density mirror ND for intensity attenuation. After passing through concave lens L1, the beam is expanded to a size larger than the fiber bundle core and transmitted to the input surface of the fiber bundle. After processing by the fiber bundle, corresponding light spots are formed. These light spots then pass through a collimator (i.e.,...) Figure 3 The L2 and L3 collimators are imaged onto the microstrip cathode. In this embodiment of the invention, the fiber bundle can consist of 50 multimode fibers, with the fiber lengths increasing sequentially. If, within the effective broadening time window, the time resolution corresponding to each ramp position of the cathode pulse is better than T, then a fiber bundle with adjacent time intervals of T is fabricated. The output surfaces of the fiber bundle are arranged and numbered sequentially according to the fiber length, with the shortest fiber numbered 1. Each increase of 1 in the number increases the transmission time of ultraviolet light in the fiber by T, thereby making the arrival time of these 50 light spots increase uniformly. The ultraviolet light is formed into 50 light spots with adjacent time intervals of T by the fiber bundle, and these light spots are imaged onto the microstrip cathode by collimators L2 and L3. Figure 3 In this invention, the first optical spot output from the fiber bundle is synchronized with the starting point of the cathode pulse ramp through a delay circuit. The 50 optical spots are sequentially synchronized at different positions on the cathode pulse ramp, with a total time of 49T on the ramp. If the effective spread time window is greater than or equal to 49T, the oscilloscope outputs 50 pulse peaks. Conversely, if the effective spread time window is less than 49T, the subsequent output optical spots, synchronized at higher positions or even the flat top of the cathode pulse ramp, generate insufficient photoelectron energy, preventing the anode electron detector from acquiring subsequent photoelectron signals. Therefore, the oscilloscope outputs fewer than 50 pulse peaks. When N pulse peaks are output, the effective spread time window is (N-1)T. Therefore, the effective spread time window of the system can also be measured using fiber bundle optics in this invention.

[0061] In this method, the electronic pulse signal output from the oscilloscope is processed, and the ratio of the time interval between two adjacent pulse peaks to the time interval between light spots (also known as the adjacent time interval) T is the electronic pulse time broadening factor at that time. Therefore, using the fiber bundle optics method, the electronic pulse time broadening factor at each slope position can be obtained in a single experiment, i.e., the relationship curve between the electronic pulse time broadening factor and the incident time of the optical signal—the electronic pulse time broadening factor function D(t). This method also simultaneously obtains the time resolution uniformity at different slope positions. It should be noted that the adjacent time interval of the fiber bundle and the number of fibers can be adjusted and manufactured as needed. If the light spot time interval is adjusted to 3T, the dynamic range uniformity at each slope position can be measured using the fiber bundle optics method.

[0062] Step S20: Determine the MCP gain function.

[0063] Optionally, in this embodiment of the invention, the MCP gain function is determined by measurement using a first measurement method or a second measurement method. In this embodiment of the invention, the relationship between the MCP gain and the signal incident time is the MCP gain function. Steps S20 and S10 are executed sequentially; that is, the electron pulse time broadening factor function is first obtained through measurement, and then the MCP gain function of step S20 is determined based on the measurement result of step S10.

[0064] Specifically, the first measurement method includes: using fiber optic bundles and a fluorescent screen to measure the relationship between MCP gain and signal incident time.

[0065] First, before measurement, the anodic electron detector at the system's backend is replaced with a fluorescent screen and a CCD (i.e., a CCD camera). During measurement, a -3kV DC voltage is applied to the microstrip cathode without a cathode pulse. The MCP input surface is grounded, and a 0.8kV DC voltage is applied to the output surface. A 4.8kV DC voltage is applied to the fluorescent screen. The static image of the fiber is measured to obtain the static distribution of the light spots. Fifty light spots with an adjacent time interval T are imaged onto the microstrip cathode by collimators L2 and L3, generating photoelectrons. These photoelectrons are then imaged onto the MCP by a magnetic lens for multiplication. After multiplication, the electrons are accelerated by the screen voltage to bombard the fluorescent screen, forming a visible light image. The intensity of this visible light is linearly related to the number of electrons output by the MCP. Finally, the visible light image is acquired by the CCD camera to obtain the static image of the fiber. Then, dynamic distribution measurements are performed. Specifically, a -3kV DC voltage and a cathode pulse are applied to the microstrip cathode. The MCP input surface is grounded, and a 0.8kV DC voltage is applied to the output surface. A 4.8kV DC voltage is applied to the fluorescent screen. A delay circuit used in time-stretching measurement is employed to delay the time, thereby obtaining a dynamic image of the optical fiber and the dynamic distribution of the light spot image. The dynamic and static distributions of the light spot image are then normalized to eliminate the influence of spatial non-uniformity of the optical pulse on the measurement. Finally, the spatial distribution of the normalized dynamic image intensity is converted into a time distribution based on the incident time of the light spot, thus obtaining the MCP gain function G(t).

[0066] The second measurement method includes: measuring by changing the electron energy to obtain the relationship between MCP gain and electron energy; obtaining the relationship between electron energy and signal incident time; and determining the relationship between MCP gain and signal incident time (i.e., the MCP gain function G(t)) based on the relationship between MCP gain and electron energy and the relationship between electron energy and signal incident time.

[0067] Step S30: Acquire the electronic pulse signal output by the X-ray diode system.

[0068] Optionally, in this embodiment of the invention, the electron pulse signal output by the X-ray diode system can be acquired using an oscilloscope, specifically as follows: Figure 3 As shown. Figure 3 Both PIN1 and PIN2 are photodiodes. PIN2 converts the 266nm laser signal generated by the laser into an electrical signal, while PIN1 converts the 800nm ​​laser signal generated by the laser into an electrical signal. Steps S30 and S10 are not sequential; they can be measured separately.

[0069] Step S40: Process the electronic pulse signal once based on the electronic pulse time-spanning function to obtain a processed pulse signal.

[0070] Optionally, in this embodiment of the invention, processing the electronic pulse signal based on the electronic pulse time-spanning factor function to obtain a processed pulse signal includes: obtaining the relationship between the electronic pulse time-spanning and the signal incident time based on the electronic pulse time-spanning factor function; determining the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points in the electronic pulse signal according to the relationship between the electronic pulse time-spanning and the signal incident time; and performing time-axis compression on the electronic pulse signal according to the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points to obtain a time-compressed pulse signal; the time-compressed pulse signal is the processed pulse signal. Specifically, performing time-axis compression on the electronic pulse signal according to the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points to obtain a time-compressed pulse signal includes: dividing the time interval between each pair of adjacent points in the electronic pulse signal by the corresponding electronic pulse time-spanning factor, while keeping the corresponding ordinate unchanged, to obtain the time-compressed pulse signal.

[0071] Step S50: Perform secondary processing on the primary processed pulse signal based on the electronic pulse time-spanning function to obtain the secondary processed pulse signal.

[0072] Optionally, in this embodiment of the invention, performing secondary processing on the primary processed pulse signal based on the electronic pulse time-spanning factor function to obtain a secondary processed pulse signal includes: obtaining the relationship between the electronic pulse time-spanning and the signal incident time based on the electronic pulse time-spanning factor function; determining the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points in the electronic pulse signal according to the relationship between the electronic pulse time-spanning and the signal incident time; and performing secondary processing on the primary processed pulse signal according to the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points to obtain a secondary processed pulse signal. Specifically, performing secondary processing on the primary processed pulse signal according to the electronic pulse time-spanning factor corresponding to the time interval between two adjacent points to obtain a secondary processed pulse signal includes: multiplying the voltage value of each point in the primary processed pulse signal by the electronic pulse time-spanning factor to obtain the secondary processed pulse signal.

[0073] Step S60: Process the secondary processing pulse signal according to the MCP gain function to obtain the reconstructed signal.

[0074] Optionally, in this embodiment of the invention, processing the secondary processing pulse signal according to the MCP gain function to obtain the reconstructed signal includes: determining the relationship between the MCP gain and the signal incident time according to the MCP gain function; determining the MCP gain corresponding to the voltage value at each point of the electronic pulse signal according to the relationship between the MCP gain and the signal incident time; and dividing the voltage value at each point of the secondary processing pulse signal by the MCP gain corresponding to the voltage value at each point to obtain the reconstructed signal.

[0075] Specifically, such as Figure 2 As shown, after determining the electronic pulse time-spanning factor function D(t) and the MCP gain function G(t), the time interval between every two points in the electronic pulse signal output by the XRD system recorded by the oscilloscope is divided by the corresponding electronic pulse time-spanning factor D, while the corresponding vertical axis (i.e., voltage value) remains unchanged, thereby compressing the time axis of the electronic pulse signal to the time scale of the input signal before amplification. Next, the voltage value at each point of the time-compressed pulse signal is multiplied by the corresponding electronic pulse time-spanning factor D; then, the voltage value at each point of the resulting pulse signal (i.e., the pulse signal with each voltage value multiplied by the corresponding electronic pulse time-spanning factor D) is divided by the corresponding MCP gain G, thus obtaining the reconstructed signal.

[0076] refer to Figure 4 , Figure 4 This is a flowchart illustrating a second embodiment of the X-ray diode signal reconstruction method provided by the present invention.

[0077] like Figure 4 As shown, in this embodiment, the following steps are performed before processing the electronic pulse signal once:

[0078] Step S30-1: Determine the MCP impulse response function.

[0079] Optionally, in this embodiment of the invention, the MCP impulse response function is obtained using femtosecond laser and scanning imaging measurements.

[0080] A large number of electrons are input simultaneously to simulate the time multiplication process of electrons in the MCP, thus obtaining the electron transit time distribution in the MCP, i.e., the MCP impulse response function. During measurement, the MCP impulse response is measured using a femtosecond laser and scanning imaging; a schematic diagram of the measurement can be found in [reference needed]. Figure 5 Specifically, such as Figure 5 As shown, the femtosecond laser signal forms a striped image after passing through slit 501, and is then imaged onto the MCP by optical lens group 502 to generate electrons, forming a one-dimensional spatially distributed electron beam. The MCP input surface is grounded, and a 0.8 kV DC voltage is applied to the output surface to multiply the electron beam. The multiplied electrons are output from the MCP output surface and then sent to the deflection system. The deflection plate 503 of the deflection system is loaded with scanning pulses, and the deflection angle of the electron beam changes continuously under the action of the scanning pulses. A 4.8 kV DC voltage is applied to the fluorescent screen 504, and the electron beam output by the deflection system is accelerated under the action of the screen voltage, bombarding different positions of the fluorescent screen 504 to form a visible light image. The visible light image is converted into a digital signal by a CCD camera and transmitted to a computer for subsequent display and processing. The vertical direction of the fluorescent screen 504 becomes the time axis of the MCP output electrons, and the electron transit time distribution in the MCP, i.e., the MCP impulse response function, is obtained.

[0081] Step S30-2: Determine the anode response function.

[0082] Optionally, in this embodiment of the invention, the anode response function is obtained by directly irradiating the anode electron detector with a femtosecond laser and then acquiring and processing the pulse signal. Specifically, the anode response function is obtained by directly irradiating the anode electron detector with a femtosecond laser to obtain the output pulse signal, and then acquiring the pulse waveform with an oscilloscope.

[0083] Step S40-1: Perform deconvolution operations on the electronic pulse signal with the anode response function and the MCP pulse response function in sequence.

[0084] In this embodiment, by taking into account the MCP pulse response function and the anode response function, the input optical signal is reconstructed using the electronic pulse signal detected by the system, the electronic pulse time-spanning function D(t), the MCP gain function G(t), the MCP pulse response function, and the anode response function, thereby further improving the accuracy of the input signal reconstruction. Specifically, after deconvolving the electronic pulse signal output by the XRD system recorded by the oscilloscope sequentially with the anode response function and the MCP pulse response function, the electronic pulse signal is then processed first and second times based on the determined electronic pulse time-spanning function. Finally, the second-processed pulse signal is processed using the determined MCP gain function to obtain the reconstructed signal. This reconstructed signal is an almost undistorted input optical signal.

[0085] In one specific embodiment, firstly, a -3 kV DC voltage and a cathode pulse with a rise time slope of 4.5 V / ps are applied to the microstrip cathode. Two light pulses from a Michelson interferometer are simultaneously incident on the system. When the light pulses synchronize approximately 200 ps after the start of the cathode pulse ramp, the anode output electrical pulse waveform obtained on the oscilloscope is as follows: Figure 6 As shown, Figure 6 The electronic pulse has two pulse peaks. Therefore, by using electronic pulse time-spanning technology, the system can distinguish between two light pulses with a time interval of 50 ps and amplify the time interval between the two light pulses to 800 ps, ​​with a time-spanning factor of about 16 times.

[0086] When the cathode pulse waveform used for electron pulse time stretching is as follows Figure 7 As shown in the dotted part, the electron pulse time-spanning factor function D(t) is obtained as follows: Figure 7 The Chinese side is shown in the dotted part.

[0087] The relationship between MCP gain and electron energy can be obtained by changing electron energy as follows: Figure 8As shown. Specifically, the anode electron detector at the back end of the system is replaced with a fluorescent screen and a CCD. A DC voltage is applied to the microstrip cathode without a cathode pulse. By changing the cathode voltage, the electron energy is changed. The CCD collects the output information intensity corresponding to electrons with different energies, thereby obtaining the relationship between MCP gain and electron energy (e.g., ...). Figure 8 As shown). According to the cathode pulse (e.g.) Figure 7 The equivalent voltage obtained by superimposing the DC bias voltage applied to the cathode (as shown) and the cathode is used to obtain the relationship between electron energy and signal incident time; based on the relationship between MCP gain and electron energy and the relationship between electron energy and signal incident time, the relationship between MCP gain and optical signal incident time can be obtained, i.e., the MCP gain function G(t), as shown. Figure 9 As shown.

[0088] use Figure 2 The input signal reconstruction processing flow shown is as follows: Figure 7 The electron pulse time-spanning factor function D(t) shown is... Figure 9 The MCP gain function G(t) shown is for... Figure 6 The input signal waveform reconstructed from the electronic pulse waveform output by the system shown is as follows: Figure 10 As shown. After compressing the pulse time axis back to the time scale before amplification, the two pulse widths are 9.9 ps and 9.1 ps, respectively. From Figure 10 The results show that the time interval between the two input signals is 51 ps, which is 2% different from the 50 ps time interval between the two light pulses output by the Michelson interferometer, thus verifying the accuracy of the input signal reconstruction algorithm.

[0089] This invention reduces the impact of inconsistent electronic pulse time-spanning ratios and MCP gain on the measurement accuracy of the XRD system by reconstructing the input signal, thereby obtaining the true input optical signal and further improving the measurement accuracy of the XRD system.

[0090] It should be noted that in other embodiments, the electron broadening factor synchronized to different ramp positions can also be made consistent through curved pulses, which will not be described in detail here.

[0091] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0092] Those skilled in the art will further 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, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. 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 implementations should not be considered beyond the scope of this invention.

[0093] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0094] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An X-ray diode signal reconstruction method, characterized by, The method comprises the following steps: determining an electron pulse time broadening ratio function; determining an MCP gain function; acquiring an electron pulse signal output by an X-ray diode system; processing the electron pulse signal once based on the electron pulse time broadening ratio function to obtain a once-processed pulse signal; the processing the electron pulse signal once based on the electron pulse time broadening ratio function to obtain a once-processed pulse signal comprises: obtaining a relationship between electron pulse time broadening and signal incidence time based on the electron pulse time broadening ratio function; determining an electron pulse time broadening ratio corresponding to a time interval between two adjacent points in the electron pulse signal according to the relationship between electron pulse time broadening and signal incidence time; and performing time axis compression on the electron pulse signal according to the electron pulse time broadening ratio corresponding to the time interval between the two adjacent points to obtain a time-compressed pulse signal; the time-compressed pulse signal is the once-processed pulse signal; processing the once-processed pulse signal twice based on the electron pulse time broadening ratio function to obtain a twice-processed pulse signal; the processing the once-processed pulse signal twice based on the electron pulse time broadening ratio function to obtain a twice-processed pulse signal comprises: multiplying a voltage value of each point in the once-processed pulse signal by the electron pulse time broadening ratio to obtain the twice-processed pulse signal; processing the twice-processed pulse signal according to the MCP gain function to obtain a reconstructed signal; the processing the twice-processed pulse signal according to the MCP gain function to obtain a reconstructed signal comprises: determining a relationship between MCP gain and signal incidence time according to the MCP gain function; determining an MCP gain corresponding to the voltage value of each point in the electron pulse signal according to the relationship between MCP gain and signal incidence time; and dividing the voltage value of each point in the twice-processed pulse signal by the MCP gain corresponding to the voltage value of each point to obtain the reconstructed signal.

2. The method of claim 1, wherein, the processing the electron pulse signal according to the electron pulse time broadening ratio corresponding to the time interval between the two adjacent points to obtain a time-compressed pulse signal comprises: dividing the time interval between each adjacent two points in the electron pulse signal by the corresponding electron pulse time broadening ratio, and keeping the corresponding ordinate unchanged to obtain the time-compressed pulse signal.

3. The method of claim 1, wherein, the determining an electron pulse time broadening ratio function comprises: obtaining a relationship between electron pulse time broadening and signal incidence time by using a fiber bundle optical method for measurement; the relationship between electron pulse time broadening and signal incidence time is the electron pulse time broadening ratio function.

4. The method of claim 1, wherein, the MCP gain function is determined by a first measurement method or a second measurement method; the first measurement method comprises: obtaining a relationship between MCP gain and signal incidence time by using a fiber bundle optical method and a fluorescent screen for measurement; the second measurement method comprises: obtaining a relationship between MCP gain and electron energy by changing electron energy for measurement; obtaining a relationship between electron energy and signal incidence time; determining a relationship between MCP gain and signal incidence time according to the relationship between MCP gain and electron energy and the relationship between electron energy and signal incidence time; the relationship between MCP gain and signal incidence time is the MCP gain function.

5. The method of claim 1, wherein, the following steps are performed before once processing the electron pulse signal: determining a MCP pulse response function; determining an anode response function; performing inverse convolution operation on the electron pulse signal with the anode response function and the MCP pulse response function in turn.

6. The method of claim 5, wherein, the MCP pulse response function is obtained by femtosecond laser and scanning imaging measurement; the anode response function is obtained by directly irradiating an anode electron detector with femtosecond laser and collecting and processing pulse signals.

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