Pulse generation device and method used for streak camera and having anti-flyback time controllable function

Abstract

The invention relates to a pulse generation device and a pulse generation method for a streak camera and with a flyback-preventing time controllable function, which are mainly used for solving the technical problem that in order to realize the flyback-preventing function, the pulse width of the existing ultrafast pulse with the flyback-preventing function is relatively large, so that the requirements of high time resolution and high repetition frequency scanning cannot be met at the same time. The pulse generation device with the flyback time controllable prevention function for the streak camera comprises a flyback time control module, a power amplification module, an ultrafast pulse generation circuit and a direct-current high-voltage source. The flyback time control module is used for adjusting the pulse width of the fixed-pulse-width rectangular wave, the power amplification module is used for adjusting the amplitude of the rectangular wave, and the ultrafast pulse generation circuit is used for adjusting the falling edge slope of the high-voltage negative pulse, so that the amplitude, the falling edge slope and the width of the high-voltage negative pulse can be adjusted. The invention further provides a pulse generation method used for the streak camera and having the flyback-preventing time controllable function.

Description

Technical Field

[0001] The invention relates to a pulse generating device and method, and in particular to a pulse generating device and method with a controllable anti-sweep time function for a streak camera. Background Art

[0002] A streak camera is a high-end scientific research instrument with high temporal and spatial resolution, which is widely used in natural science research. Its imaging principle is that a time-series light signal generates photoelectrons on the photocathode of the streak image converter. The photoelectrons are focused by the internal electromagnetic field and then pass through the deflection plate. A time-varying linear ramp voltage or sinusoidal voltage is applied to the deflection plate to cause the photoelectrons to shift in the scanning direction, converting the one-dimensional spatial resolution into time resolution, thereby achieving ultrafast imaging in the time dimension.

[0003] Generally, streak cameras usually use the falling edge of a negative pulse from 0V to negative high voltage (-HV) as the scanning voltage, and select the area where the voltage slope is approximately linear as the working area during the scanning process. In a single scanning cycle, after the scanning voltage reaches the bottom, it gradually rises back to 0V, waiting for the next trigger signal. Since the time resolution capability of a streak camera is closely related to its scanning gear selection, a higher scanning gear also has a higher time resolution capability. Different scanning gears correspond to different full-screen time ranges. Generally speaking, the higher the scanning gear, the shorter the full-screen time range. When selecting a scanning gear, it generally corresponds to the luminescence duration of the object to be measured. Therefore, in order to obtain higher time resolution, a scanning gear with a longer full-screen time is usually not selected.

[0004] However, in actual application scenarios, streak cameras often encounter the problem that the luminescence time of the detection target is too long, even longer than the entire cycle of the negative pulse, which means that a longer full-screen time range is required. The effective physical information of the detection target is mainly contained in the initial short time range. At this time, the scanning voltage is in the rising edge period from negative high voltage (-HV) to 0V. The photocathode is still emitting photoelectrons, and at the same time, the photoelectrons will be scanned from the opposite direction by the rising edge voltage of the restored level and imaged on the fluorescent screen. This phenomenon is called retrace. Due to the existence of the rising edge of the pulse, this retrace is inevitable. How to make the rising edge of the pulse avoid the luminescence tailing phenomenon of the object to be measured in time has become a difficult problem in engineering applications.

[0005] In the prior art, the pulse width of ultrafast pulses with anti-scanning function generally needs to be controlled above 100μs to avoid luminous tailing. However, in order to obtain higher time resolution or the need for high repetition rate scanning of streak image converters, the single pulse cycle time cannot be too long, and it needs to be matched accordingly according to the use scenario of the streak camera. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problem that the existing ultrafast pulses with anti-sweep function have a large pulse width to achieve the anti-sweep function, resulting in the inability to simultaneously meet the requirements of high time resolution and high repetition rate scanning. A pulse generating device and method with controllable anti-sweep time for a streak camera are proposed.

[0007] To solve the above technical problems, the technical solutions provided by the present invention are as follows:

[0008] A pulse generating device with anti-flyback time controllable function for a streak camera, which is special in that it includes a flyback time control module, a power amplification module, an ultrafast pulse generating circuit, and a DC high voltage source;

[0009] The input end of the flyback time control module is used to input a clock signal, and the flyback time control module is used to generate a fixed pulse width rectangular wave, and the pulse width of the fixed pulse width rectangular wave is T;

[0010] The input end of the power amplifier module is connected to the output end of the flyback time control module, and the power amplifier module is used to amplify the power of the fixed pulse width rectangular wave and output the rectangular wave;

[0011] The ultrafast pulse generating circuit is used to generate a high-voltage negative pulse with a pulse width of T, and the ultrafast pulse generating circuit includes a first N MOSFET tube, a power limiting resistor R and a main capacitor C;

[0012] The gate of the first N MOSFET tube is the input end of the ultrafast pulse generating circuit, connected to the output end of the power amplifier module, the drain of the first N MOSFET tube is connected to one end of the power limiting resistor R, and the other end of the power limiting resistor R is connected to the DC high voltage source;

[0013] The drain of the first N MOSFET tube is also connected to one end of the main capacitor C, and the other end of the main capacitor C is the output end of the ultrafast pulse generating circuit, which is used to connect to the streak camera;

[0014] A source of the first N MOSFET is connected to the power ground GND.

[0015] Further, the power amplifier module includes an N MOSFET tube and a P MOSFET tube; the gates of the N MOSFET tube and the PMOSFET tube are connected, and their common connection point is connected to the input end of the power amplifier module and the output end of the retrace time control module; the drain of the N MOSFET tube is connected to an external power supply, and the amplitude VCC of the external power supply is greater than the amplitude of the fixed pulse width rectangular wave; the source of the P MOSFET tube is connected to the power ground GND, the source of the NMOSFET tube is connected to the drain of the P MOSFET tube, and their common connection point is connected to the gate of the first N MOSFET tube as the output end of the power amplifier module; the rectangular wave pulse width output by the power amplifier module is T, and the amplitude is VCC.

[0016] Furthermore, a discharge resistor R1 is connected between the gate and source of the first N MOSFET tube to prevent the input end of the ultrafast pulse generating circuit from being falsely triggered by stray signals.

[0017] Further, the retrace time control module includes a dual trigger U5B, a capacitor C11 or an adjustable capacitor, a resistor R12 and a diode D2;

[0018] The reset pin of the dual trigger U5B is connected to one end of the capacitor C11 or the adjustable capacitor, and the other end of the capacitor C11 or the adjustable capacitor is grounded;

[0019] The data input pin of dual trigger U5B is grounded and connected to VDD;

[0020] The clock input pin of the dual trigger U5B is the input end of the flyback time control module, which is used to connect to an external clock source and input a clock signal;

[0021] The set pin of the dual flip-flop U5B is connected to VDD;

[0022] The output pin of the dual trigger U5B is the output end of the flyback time control module, which is connected to the input end of the power amplifier module;

[0023] One end of the resistor R12 is connected to the inverting output pin of the dual trigger U5B, and the other end is connected to one end of the capacitor C11 or the adjustable capacitor;

[0024] The anode of the diode D2 is connected to the inverting output pin, and the cathode is connected to the capacitor C11 or one end of the adjustable capacitor.

[0025] The present invention also provides a pulse generating method with controllable anti-scan time for a streak camera. The method is based on the above-mentioned pulse generating device with controllable anti-scan time for a streak camera, and the method comprises the following steps:

[0026] S1. Input a clock signal into the flyback time control module, and the flyback time control module outputs a fixed pulse width rectangular wave with fast leading and trailing edges, and the pulse width of the fixed pulse width rectangular wave is T;

[0027] S2, a fixed pulse width rectangular wave is input to the power amplifier module for power amplification, and the power amplifier module outputs a rectangular wave with a pulse width of T and an amplified amplitude;

[0028] S3, the rectangular wave is input to the ultrafast pulse generating circuit, and the ultrafast pulse generating circuit outputs a high-voltage negative pulse with a pulse width of T and an adjustable falling slope; the specific steps are:

[0029] S3.1, the first N MOSFET is turned off, and the DC high voltage source charges the main capacitor C through the power limiting resistor R; the voltage of the DC high voltage source is HV, then the potential of one end of the main capacitor C is HV, and the potential of the other end is 0V;

[0030] S3.2, the rectangular wave is input to the first N MOSFET tube, and the rising edge of the rectangular wave triggers the first N MOSFET tube to turn on; one end of the main capacitor C forms a high-voltage falling edge from HV to 0V;

[0031] S3.3, the other end of the main capacitor C forms a falling edge from 0V to -HV, and the -HV potential is maintained for T;

[0032] S3.4, the falling edge of the rectangular wave triggers the first N MOSFET to turn off, the potential of one end of the main capacitor C is restored to HV, and the potential of the other end forms a rising edge from -HV to 0V, generating a high-voltage negative pulse with controllable anti-flyback time function for the streak camera.

[0033] Furthermore, step S1 is specifically as follows:

[0034] S1.1, when the clock input pin does not input the clock signal, the inverting output pin in the retrace time control module is at a high level and the output pin is at a low level; the inverting output pin charges the capacitor C11 through the resistor R12 and the diode D2 until the capacitor C11 is fully charged; the reset pin becomes a high level;

[0035] S1.2. Input the clock signal to the clock input pin. The rising edge of the clock signal triggers the inverting output pin to change from high level to low level, and the output pin to change from low level to high level.

[0036] S1.3, capacitor C11 starts to discharge, and the potential of the reset pin decreases during the discharge process until the potential of the reset pin is less than the specified threshold of the reset pin, causing the reset pin to change from a high level to a low level;

[0037] S1.4. The low level of the reset pin enables the output pin to change from high level to low level, and the output pin outputs a fixed pulse rectangular wave; by adjusting the capacitance of capacitor C11, the discharge time is adjusted to control the pulse width of the fixed pulse rectangular wave to T.

[0038] Furthermore, step S2 is specifically as follows:

[0039] S2.1, a fixed pulse width rectangular wave is input to the power amplifier module, the rising edge of the fixed pulse width rectangular wave triggers the NMOSFET tube to turn on, the PMOSFET tube to turn off, and the potential at the source of the NMOSFET tube rises to the voltage value of VCC;

[0040] S2.2. After time T, the falling edge of the fixed pulse width rectangular wave triggers the P MOSFET to turn on and the NMOSFET to turn off. At the same time, the potential at the drain of the P MOSFET is pulled to 0V, and the output end of the power amplifier module outputs a rectangular wave with a pulse width of T and an amplitude of VCC.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The pulse generating device with controllable anti-flyback time for streak camera of the present invention comprises a flyback time control module, a power amplifier module, an ultrafast pulse generating circuit, and a DC high voltage source. The flyback time control module is used to adjust the pulse width of the fixed pulse width rectangular wave, the power amplifier module is used to adjust the amplitude of the rectangular wave, and the ultrafast pulse generating circuit is used to adjust the falling edge slope of the high voltage negative pulse, so as to achieve that the amplitude, falling edge slope and width of the high voltage negative pulse can be adjusted.

[0043] 2. The pulse generator with controllable anti-flyback time for streak cameras of the present invention uses a P-NMOSFET pair tube push-pull output circuit to form a power amplifier module. The push-pull output circuit has a strong driving capability and fast leading and trailing edge characteristics, and can conveniently retain the pulse width of a fixed pulse width rectangular wave, thereby meeting the use requirements of streak cameras. The rectangular wave after power amplification can also ensure the normal operation of the high-voltage switch device at the subsequent stage.

[0044] 3. The present invention is a pulse generating device with controllable anti-return time function for a streak camera. The ultrafast pulse generating circuit uses high-voltage switching devices such as MOSFET, which can meet the scanning range of the streak camera of 2ns to 1000μs or slower speeds, and at the same time has the function of controllable rise time of the pulse rising edge within a single pulse cycle.

[0045] 4. The pulse generation method with controllable anti-flyback time function for a streak camera of the present invention, by inputting a clock signal into the flyback time control module, the flyback time control module generates a fixed pulse width rectangular wave with fast leading and trailing edges, and the pulse width T of the fixed pulse width rectangular wave is adjustable. The fixed pulse width rectangular wave is input to the power amplifier module for power amplification, and the power amplifier module outputs a rectangular wave with a pulse width of T and adjustable amplitude. The rectangular wave triggers the ultrafast pulse generation circuit to generate a high-voltage negative pulse with a pulse width of T and an adjustable falling edge slope, thereby achieving adjustable amplitude, falling edge slope and width of the high-voltage negative pulse. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A connection block diagram of an embodiment of a pulse generating device with controllable anti-flyback time for a streak camera according to the present invention;

[0047] Figure 2 It is a circuit diagram of a flyback time control module in an embodiment of a pulse generating device with controllable anti-flyback time function for a streak camera of the present invention;

[0048] Figure 3 It is a circuit diagram of a power amplification module in an embodiment of a pulse generating device with controllable anti-flyback time for a streak camera of the present invention;

[0049] Figure 4 A circuit diagram of an ultrafast pulse generating circuit in an embodiment of a pulse generating device with controllable anti-flyback time function for a streak camera of the present invention;

[0050] Figure 5 It is a schematic diagram of a high-voltage negative pulse outputted in an embodiment of a pulse generating device with controllable anti-flyback time for a streak camera according to the present invention;

[0051] Figure 6 Schematic diagram of no flyback pulse. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0053] The present invention is a pulse generating device with controllable anti-scanning time for a streak camera, such as Figure 1 As shown, it includes a flyback time control module, a power amplification module and an ultrafast pulse generating circuit which are connected in sequence, and a DC high voltage source for supplying power to the ultrafast pulse generating circuit.

[0054] like Figure 2As shown, the retrace time control module includes a dual trigger U5B, a capacitor C11 or an adjustable capacitor, a resistor R12 and a diode D2; wherein the dual trigger U5B adopts 74VHC74, the reset pin RD2 of the dual trigger U5B is connected to one end of the capacitor C11 or the adjustable capacitor, and the other end of the capacitor C11 or the adjustable capacitor is grounded; the data input pin D2 of the dual trigger U5B is grounded and connected to VDD; the clock input pin CP2 of the dual trigger U5B is the input end of the retrace time control module, which is used to connect an external clock source and input a clock signal; the set pin SD2 of the dual trigger U5B is connected to VDD; the output pin Q2 of the dual trigger U5B is the output end of the retrace time control module; one end of the resistor R12 is connected to the inverting output pin Q2 (not) of the dual trigger U5B, and the other end is connected to the capacitor C11; the positive electrode of the diode D2 is connected to the inverting output pin Q2 (not), and the negative electrode is connected to the capacitor C11. The pulse width T is controlled by changing the capacitance of the capacitor C11 or using an adjustable capacitor to adjust the discharge time of the capacitor C11.

[0055] High-voltage switching devices are required in ultrafast pulse generation circuits to control the on and off of high voltage and high current. Since the gate junction capacitance of high-voltage switching devices is large, in order to ensure the normal operation of the subsequent high-voltage switching devices, it is necessary to amplify the power of the fixed pulse width rectangular wave in order to better drive the subsequent high-voltage switching devices.

[0056] In view of the fact that the push-pull output circuit has a strong driving capability and fast leading and trailing edge characteristics, it is relatively convenient to retain the pulse width of the fixed pulse width rectangular wave, thereby meeting the use requirements of the streak camera. Therefore, this embodiment uses a PN MOSFET pair of tubes to form a power amplifier module. Figure 3 As shown, the power amplifier module includes an NMOSFET tube and a PMOSFET tube. The gates of the NMOSFET tube and the PMOSFET tube are connected, and their common connection point is used as the input end of the power amplifier module and connected to the output pin Q2 of the dual trigger U5B; the drain of the NMOSFET tube is connected to VCC, the source of the PMOSFET tube is connected to the power ground GND, and the source of the NMOSFET tube is connected to the drain of the PMOSFET tube and serves as the output end of the power amplifier module. In this embodiment, VCC is 12V.

[0057] like Figure 4As shown, the ultrafast pulse generating circuit includes a first N MOSFET tube, a power limiting resistor R, a main capacitor C, and a discharge resistor R1. The gate of the first N MOSFET tube is the input end of the ultrafast pulse generating circuit. The gate of the first N MOSFET tube is connected to the output end of the power amplifier module, the drain of the first N MOSFET tube is connected to one end of the power limiting resistor R, the other end of the power limiting resistor R is connected to a DC high voltage source, the drain of the first N MOSFET tube is also connected to one end of the main capacitor C, and the other end of the main capacitor C is the output end, which is used to connect to the streak camera. In this embodiment, the streak camera is represented by a load Rs, one end of the load Rs is connected, and the other end of the load Rs is connected to the power ground GND. The source of the first N MOSFET tube is connected to the power ground GND. A discharge resistor R1 is also connected between the gate and the source of the first N MOSFET tube to prevent the input end of the ultrafast pulse generating circuit from being mistakenly triggered by stray signals.

[0058] Based on the above-mentioned pulse generating device, the present invention also provides a pulse generating method with controllable anti-scanning time for a streak camera, which specifically comprises the following steps:

[0059] S1. Input a clock signal, such as a Gaussian pulse, into the flyback time control module. The flyback time control module outputs a fixed pulse width rectangular wave with fast leading and trailing edges. The pulse width of the fixed pulse width rectangular wave is T. Specifically:

[0060] S1.1, when the clock input pin CP2 does not input the clock signal, the inverting output pin Q2 (not) in the retrace time control module is at a high level, and the output pin is at a low level; the inverting output pin Q2 (not) charges the capacitor C11 through the resistor R12 and the diode D2 until the capacitor C11 is fully charged; the reset pin RD2 becomes a high level;

[0061] S1.2. Input the clock signal to the clock input pin CP2. The rising edge of the clock signal triggers the inverting output pin Q2 (non) to change from high level to low level, and the output pin changes from low level to high level.

[0062] S1.3, capacitor C11 starts to discharge, and the potential of reset pin RD2 decreases during the discharge process until the potential of reset pin RD2 is less than the threshold of reset pin RD2, so that reset pin RD2 changes from high level to low level;

[0063] S1.4, the low level of the reset pin RD2 enables the output pin to change from high level to low level, and the output pin outputs a fixed pulse rectangular wave; by adjusting the capacitance of the capacitor C11, the discharge time is adjusted, so as to control the pulse width of the fixed pulse rectangular wave to T;

[0064] S2, a fixed pulse width rectangular wave is input to the power amplifier module for power amplification, and the power amplifier module outputs a rectangular wave with a pulse width of T and an amplified amplitude; specifically:

[0065] S2.1, a fixed pulse width rectangular wave is input to the power amplifier module, the rising edge of the fixed pulse width rectangular wave triggers the NMOSFET tube to turn on, the PMOSFET tube to turn off, and the potential at the source of the NMOSFET tube rises to a voltage value of 12V;

[0066] S2.2, after time T, the falling edge of the fixed pulse width rectangular wave triggers the P MOSFET to turn on and the NMOSFET to turn off; at the same time, the potential at the drain of the P MOSFET is quickly pulled to 0V, and the output end of the power amplifier module outputs a rectangular wave with a pulse width of T and an amplitude of VCC;

[0067] S3, the rectangular wave is input to the ultrafast pulse generating circuit, and the ultrafast pulse generating circuit outputs a high-voltage negative pulse with a pulse width of T and an adjustable falling slope; the specific steps are:

[0068] S3.1, the first N MOSFET is turned off, and the DC high voltage source charges the main capacitor C through the power limiting resistor R; the voltage of the DC high voltage source is HV, then the potential of one end of the main capacitor C is HV, and the potential of the other end is 0V;

[0069] S3.2, the rectangular wave is input to the first N MOSFET tube, and the rising edge of the rectangular wave triggers the first N MOSFET tube to turn on; one end of the main capacitor C forms a high-voltage falling edge from HV to 0V;

[0070] S3.3. Since the voltage across the main capacitor C cannot change suddenly, a falling edge from 0V to -HV is formed at the other end of the main capacitor C. The maintenance time of the -HV potential depends on the pulse width of the rectangular wave.

[0071] S3.4, the falling edge of the rectangular wave triggers the first N MOSFET to turn off, the potential of one end of the main capacitor C is restored to HV, and the potential of the other end forms a rising edge from -HV to 0V, and the other end of the main capacitor C outputs a complete high-voltage negative pulse, such as Figure 5 By adjusting the time constant of the pulse loop where the main capacitor C is located and the conduction speed of the first N MOSFET tube, the falling edge slope of the high-voltage negative pulse can be adjusted.

[0072] like Figure 6 As shown in the figure, it is a schematic diagram of a non-flyback pulse, and T0 is the pulse width. Figure 6As shown in the pulse, the high-voltage negative pulse output by the present invention has a stable and slow falling edge slope, and the pulse width can be adjusted to meet the scanning range of the streak camera of 2ns to 1000μs or slower speed, and at the same time has the function of controllable rising time of the pulse rising edge within a single pulse cycle.

Claims

1. A pulse generator with controllable anti-flyback time for a streak camera, characterized in that: It includes a flyback time control module, a power amplification module, an ultrafast pulse generation circuit, and a DC high voltage source; The input end of the flyback time control module is used to input a clock signal, and the flyback time control module is used to generate a fixed pulse width rectangular wave, and the pulse width of the fixed pulse width rectangular wave is T; The input end of the power amplifier module is connected to the output end of the flyback time control module, and the power amplifier module is used to amplify the power of the fixed pulse width rectangular wave and output the rectangular wave; The ultrafast pulse generating circuit is used to generate a high-voltage negative pulse with a pulse width of T, and the ultrafast pulse generating circuit includes a first N MOSFET tube, a power limiting resistor R and a main capacitor C; The gate of the first N MOSFET tube is the input end of the ultrafast pulse generating circuit, connected to the output end of the power amplifier module, the drain of the first N MOSFET tube is connected to one end of the power limiting resistor R, and the other end of the power limiting resistor R is connected to the DC high voltage source; The drain of the first N MOSFET tube is also connected to one end of the main capacitor C, and the other end of the main capacitor C is the output end of the ultrafast pulse generating circuit, which is used to connect to the streak camera; A source of the first N MOSFET is connected to the power ground GND.

2. The pulse generating device with controllable anti-scanning time for streak camera according to claim 1, characterized in that: The power amplifier module includes an N MOSFET tube and a P MOSFET tube; the gate electrodes of the N MOSFET tube and the PMOSFET tube are connected, and their common connection point is connected to the input end of the power amplifier module and the output end of the retrace time control module; the drain electrode of the NMOSFET tube is connected to an external power supply, and the amplitude VCC of the external power supply is greater than the amplitude of the fixed pulse width rectangular wave; the source electrode of the PMOSFET tube is connected to the power ground GND, the source electrode of the N MOSFET tube is connected to the drain electrode of the P MOSFET tube, and their common connection point is connected to the gate electrode of the first N MOSFET tube as the output end of the power amplifier module; the rectangular wave pulse width output by the power amplifier module is T, and the amplitude is VCC.

3. The pulse generating device with controllable anti-scanning time for streak camera according to claim 2, characterized in that: A discharge resistor R1 is also connected between the gate and source of the first N MOSFET tube to prevent the input end of the ultrafast pulse generating circuit from being falsely triggered by stray signals.

4. The pulse generating device with controllable anti-scanning time for streak camera according to claim 3, characterized in that: The retrace time control module includes a dual trigger U5B, a capacitor C11 or an adjustable capacitor, a resistor R12 and a diode D2; The reset pin of the dual trigger U5B is connected to one end of the capacitor C11 or the adjustable capacitor, and the other end of the capacitor C11 or the adjustable capacitor is grounded; The data input pin of dual trigger U5B is grounded and connected to VDD; The clock input pin of the dual trigger U5B is the input end of the flyback time control module, which is used to connect the external clock source and input the clock signal; The set pin of the dual flip-flop U5B is connected to VDD; The output pin of the dual trigger U5B is the output end of the flyback time control module, which is connected to the input end of the power amplifier module; One end of the resistor R12 is connected to the inverting output pin of the dual trigger U5B, and the other end is connected to one end of the capacitor C11 or the adjustable capacitor; The anode of the diode D2 is connected to the inverting output pin, and the cathode is connected to the capacitor C11 or one end of the adjustable capacitor.

5. A pulse generating method with controllable anti-scan time for a streak camera, based on the pulse generating device with controllable anti-scan time for a streak camera according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, input a clock signal into the retrace time control module, and the retrace time control module outputs a fixed pulse width rectangular wave with fast leading and trailing edges, and the pulse width of the fixed pulse width rectangular wave is T; S2, a fixed pulse width rectangular wave is input to the power amplifier module for power amplification, and the power amplifier module outputs a rectangular wave with a pulse width of T and an amplified amplitude; S3, the rectangular wave is input to the ultrafast pulse generating circuit, and the ultrafast pulse generating circuit outputs a high-voltage negative pulse with a pulse width of T and an adjustable falling slope; the specific steps are: S3.1, the first N MOSFET is turned off, and the DC high voltage source charges the main capacitor C through the power limiting resistor R; the voltage of the DC high voltage source is HV, then the potential of one end of the main capacitor C is HV, and the potential of the other end is 0V; S3.2, the rectangular wave is input to the first N MOSFET tube, and the rising edge of the rectangular wave triggers the first N MOSFET tube to turn on; one end of the main capacitor C forms a high-voltage falling edge from HV to 0V; S3.3, the other end of the main capacitor C forms a falling edge from 0V to -HV, and the -HV potential is maintained for T; S3.4, the falling edge of the rectangular wave triggers the first N MOSFET to be turned off, the potential of one end of the main capacitor C is restored to HV, and the potential of the other end forms a rising edge from -HV to 0V, generating a high-voltage negative pulse with controllable anti-flyback time function for the streak camera.

6. The pulse generation method with controllable anti-flyback time for a streak camera according to claim 5, characterized in that: Step S1 is specifically as follows: S1.1, when the clock input pin of the retrace time control module does not input the clock signal, the inverting output pin in the retrace time control module is at a high level and the output pin is at a low level; the inverting output pin charges the capacitor C11 through the resistor R12 and the diode D2 until the capacitor C11 is fully charged; the reset pin becomes a high level; S1.

2. Input the clock signal to the clock input pin. The rising edge of the clock signal triggers the inverting output pin to change from high level to low level, and the output pin to change from low level to high level. S1.3, capacitor C11 starts to discharge, and the potential of the reset pin decreases during the discharge process until the potential of the reset pin is less than the specified threshold of the reset pin, causing the reset pin to change from a high level to a low level; S1.

4. The low level of the reset pin enables the output pin to change from high level to low level, and the output pin outputs a fixed pulse rectangular wave; by adjusting the capacitance of capacitor C11, the discharge time is adjusted to control the pulse width of the fixed pulse rectangular wave to T.

7. The pulse generation method with controllable anti-flyback time for a streak camera according to claim 6, characterized in that: Step S2 is specifically as follows: S2.1, a fixed pulse width rectangular wave is input to the power amplifier module, the rising edge of the fixed pulse width rectangular wave triggers the N MOSFET tube to turn on, the P MOSFET tube to turn off, and the potential at the source of the N MOSFET tube rises to the voltage value of VCC; S2.

2. After time T, the falling edge of the fixed pulse width rectangular wave triggers the P MOSFET to turn on and the NMOSFET to turn off. At the same time, the potential at the drain of the P MOSFET is pulled to 0V, and the output end of the power amplifier module outputs a rectangular wave with a pulse width of T and an amplitude of VCC.

Images