High-power cold cathode electron gun protection system based on multi-point temperature measurement

Abstract

The invention relates to a high-power cold cathode electron gun protection system based on multi-point temperature measurement, and the system comprises a temperature measurement device which comprises a plurality of temperature sensors, and each temperature sensor is connected with different parts of an electron gun; the temperature sensors are used for monitoring temperature signals of different parts of the electron gun; the temperature detection and analysis system is connected with the temperature measuring device; the temperature detection and analysis system is used for receiving the temperature signal and outputting an adjustment signal of a working parameter corresponding to the electron gun according to the temperature signal; and the electronic gun control system is connected with the temperature detection and analysis system and is used for receiving the adjustment signal and adjusting the working parameters corresponding to the electronic gun according to the adjustment signal, so that the temperature of the electronic gun is maintained in a set range. The long-term working stability and reliability of the high-power cold cathode electron gun can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of cold cathode electron guns, and in particular to a high-power cold cathode electron gun protection system based on multi-point temperature measurement. Background Art

[0002] Cold cathode gas discharge electron guns based on plasma anodes have been widely used in vacuum metallurgy, EB-PVD, material surface treatment, additive manufacturing and other technical fields. Compared with hot cathode electron guns, the cathode of cold cathode gas discharge electron guns has a long life and can be reused after cleaning; the gun body has a simple structure, and under the same power conditions, it is lighter and smaller, and its advantages as an indoor mobile gun are more obvious; the cathode of cold cathode gas discharge electron guns can be made into a variety of shapes, and a variety of beam spot morphologies such as circular, annular, and square can be obtained, which has great application potential in the industrial field.

[0003] When using a high-power cold cathode electron gun, the electron gun beam output status is usually judged by detecting the operating voltage, beam size, beam spot morphology, etc. These data cannot reflect the state of the electron beam in the discharge chamber and beam channel inside the electron gun. Due to the abnormal increase in gas delivery volume, when the acceleration voltage remains unchanged, the cathode emission surface will climb upward along the outer surface of the connecting ring, causing discharge between the cathode ring and the inner wall of the upper section of the electron gun, which not only distorts the electron beam spot, but also causes the temperature of the upper section of the electron gun to rise sharply, affecting the sealing performance of the electron gun and the stability and reliability of long-term operation; improper adjustment of the pre-focusing coil parameters may easily lead to too many electrons being intercepted by the anode, which not only reduces the effective electron beam that passes through the anode and the beam guide channel to reach the workpiece surface, and reduces the effective beam power, but also causes the anode temperature to rise sharply, affecting the sealing between the anode and the upper section and the lower section of the electron gun, and affecting the long-term stability of the electron gun; some special processes require cold cathode electron beam scanning, and if the scanning parameters are inappropriate, the electron beam is likely to scan to the inner edge of the lower end of the beam guide channel, and the beam current in the scanning state is too large, which may not only easily cause damage to the beam guide channel, but also introduce additional chemical elements into the processed material, affecting the processing quality. Summary of the invention

[0004] The present application provides a high-power cold cathode electron gun protection system based on multi-point temperature measurement, which solves the problem of how to improve the long-term working stability and reliability of the high-power cold cathode electron gun and improve the processing quality of the cold cathode electron beam.

[0005] The present application provides a high-power cold cathode electron gun protection system based on multi-point temperature measurement, comprising:

[0006] A temperature measuring device, the temperature measuring device comprises a plurality of temperature sensors, each temperature sensor is connected to a different part of the electron gun; each temperature sensor is used to monitor the temperature signal of a different part of the electron gun;

[0007] A temperature detection and analysis system is connected to the temperature measuring device; the temperature detection and analysis system is used to receive a temperature signal and output an adjustment signal of a working parameter corresponding to the electron gun according to the temperature signal;

[0008] The electron gun control system is connected to the temperature detection and analysis system, and is used to receive an adjustment signal and adjust the corresponding working parameters of the electron gun according to the adjustment signal to maintain the temperature of the electron gun within a set range.

[0009] Further, the temperature measuring device includes a first temperature sensor, which is connected to the cathode water outlet pipe and is used to monitor the temperature signal of the cathode water outlet pipe;

[0010] The temperature detection and analysis system is used to receive the cathode water outlet pipe temperature signal, and output a high-voltage adjustment signal when the cathode water outlet pipe temperature signal exceeds a first preset range;

[0011] The electron gun control system includes a high voltage control system, which is used to receive a high voltage adjustment signal and adjust the voltage.

[0012] Furthermore, the temperature measuring device further comprises a second temperature sensor, which is connected to the anode water outlet pipe and is used to monitor the temperature signal of the anode water outlet pipe;

[0013] The temperature detection and analysis system is also used to receive the temperature signal of the anode water outlet pipe, and output the pre-focusing coil driving current adjustment signal when the temperature signal of the anode water outlet pipe exceeds the second preset range;

[0014] The electron gun control system also includes a pre-focusing control system, which is used to receive a pre-focusing coil driving current adjustment signal and adjust the pre-focusing coil current parameters.

[0015] Furthermore, the temperature measuring device further comprises a third temperature sensor, which is connected to the upper section of the electron gun and is used to monitor the temperature signal of the outer surface of the upper section of the electron gun;

[0016] The temperature detection and analysis system is also used to receive a temperature signal of the outer surface of the upper section of the electron gun, and output a high-voltage adjustment signal when the temperature signal of the outer surface of the upper section of the electron gun exceeds a third preset range;

[0017] The electron gun control system includes a high voltage control system, which is used to receive a high voltage adjustment signal and adjust the voltage.

[0018] Furthermore, the temperature measuring device further comprises a fourth temperature sensor, which is connected to the water outlet pipe of the beam guiding channel and is used to monitor the temperature signal of the water outlet pipe of the beam guiding channel;

[0019] The temperature detection and analysis system is also used to receive a temperature signal of a water outlet pipe of a beam guide channel, and output a main focusing coil driving current adjustment signal when the temperature signal of the water outlet pipe of the beam guide channel exceeds a fourth preset range and the scanning coil is not working;

[0020] The electron gun control system also includes a main focusing control system, which is used to receive a main focusing coil driving current adjustment signal and adjust the main focusing coil current parameters.

[0021] Furthermore, the temperature measuring device further comprises a fourth temperature sensor, which is connected to the water outlet pipe of the beam guiding channel and is used to monitor the temperature signal of the water outlet pipe of the beam guiding channel;

[0022] The temperature detection and analysis system is also used to receive a temperature signal of a water outlet pipe of a beam guiding channel, and output a scanning coil driving current adjustment signal when the temperature signal of the water outlet pipe of the beam guiding channel exceeds a fourth preset range and the scanning coil is working;

[0023] The electron gun control system also includes a scanning control system, which is used to receive a scanning coil driving current adjustment signal and adjust the scanning coil current parameters.

[0024] Furthermore, it also includes an alarm unit, which is connected to the temperature detection and analysis system;

[0025] The temperature detection and analysis system is also used to output an alarm signal when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun does not reach the set range;

[0026] The alarm unit is used to receive alarm signals and generate alarms.

[0027] Furthermore, the temperature detection and analysis system is also used to set the high voltage given signal to 0 when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset time and the temperature of the electron gun does not reach the set range;

[0028] The high voltage control system is also used to turn off the high voltage output when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset time and the temperature of the electron gun does not reach a set range.

[0029] Furthermore, it also includes a stabilized DC power supply and a plurality of connection resistors; one end of each temperature sensor is connected to the stabilized DC power supply through the connection resistor, and the other end is grounded.

[0030] Furthermore, it also includes a plurality of operational amplifier circuits; each operational amplifier circuit is respectively connected between a corresponding temperature sensor and a temperature detection and analysis system.

[0031] The above technical solution of the present application has the following advantages:

[0032] The high-power cold cathode electron gun protection system based on multi-point temperature measurement provided by the present application adopts multi-point temperature measurement to detect the temperature of key components of the high-power cold cathode electron gun. During the actual use of the electron gun, the state of the internal beam of the cold cathode electron gun can be effectively grasped, and the system has practical value. According to the temperature detected by the multi-point temperature measurement, the working parameters of the electron gun are automatically adjusted to maintain the temperature of the electron gun within the set range, so that the high-power cold cathode electron gun can be protected, the stability and reliability of the long-term operation of the high-power cold cathode electron gun can be improved, and the processing quality of the cold cathode electron beam can be improved. Through the temperature detection and analysis system, the temperature abnormal points of the key components of the electron gun can be quickly and accurately found and the working parameters can be adjusted, so as to reduce the number of manual interventions and avoid the shortcomings of slow manual adjustment and low precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of a high-power cold cathode electron gun protection system based on multi-point temperature measurement provided by this application;

[0035] Figure 2 A schematic diagram of the temperature measurement point setting of the high-power cold cathode electron gun provided in this application;

[0036] Figure 3 This is a software program flow chart of the temperature detection and analysis system provided in this application.

[0037] Figure numerals: 1. temperature detection and analysis system; 2. high-voltage control system; 3. pre-focusing control system; 4. main focusing control system; 5. scanning control system; 6. water-cooled cathode; 601. cathode water inlet pipe; 602. cathode water outlet pipe; 603. high-voltage wire; 7. insulating component; 8. connecting ring; 9. upper section of electron gun; 901. gas guide pipe; 10. anode; 1001. anode water inlet pipe; 1002. anode water outlet pipe; 11. pre-focusing coil; 12. main focusing coil; 13. beam guiding channel; 1301. beam guiding channel water inlet pipe; 1302. beam guiding channel water outlet pipe; 14. scanning coil; 15. lower section of electron gun; 16. electron beam; 17. alarm unit. DETAILED DESCRIPTION

[0038] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0039] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0040] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0041] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" means "two or more".

[0042] Compared with the cathode of the traditional electron beam source that directly or indirectly heats the filament, the cathode emission area of ​​the cold cathode gas discharge electron beam source can be made very large. Pure aluminum with high electron emission rate is used as the cathode material. The power can reach hundreds of kW. The cathode is bombarded by a large number of positive ions, generating a lot of heat. The beam passes through the anode hole through the electrostatic convergence of the electrostatic field between the cathode and the cathode to form the final working beam, but a small part of the beam hits the anode, and its kinetic energy is converted into heat energy and absorbed by the anode, causing the anode temperature to rise. After passing through the anode hole, the electron beam is converged by the pre-focusing coil and the focusing coil, but due to the large diameter of the cold cathode electron beam, part of the beam will hit the beam channel, causing the beam channel temperature to rise. Therefore, it is necessary to provide a water cooling unit for the cathode, anode, and beam channel. Deionized water is used for cooling water to prevent the conductive ions in the water from transmitting the cathode high voltage to other equipment and causing failures.

[0043] Therefore, by detecting the cathode cooling water temperature, the anode cooling water temperature, the electron gun upper surface temperature, and the beam guide channel temperature, the beam state in the discharge chamber and the beam channel can be judged, and the beam can be output efficiently and stably by adjusting the working voltage, pre-focusing coil current, main focusing coil current, and scanning coil current amplitude.

[0044] In order to improve the stability and reliability of long-term operation of high-power cold cathode electron guns and improve the processing quality of cold cathode electron beams, the present application provides a high-power cold cathode electron gun protection system based on multi-point temperature measurement. According to the temperature detected by multi-point temperature measurement, the state of the internal beam of the cold cathode electron gun is judged, and the high-power cold cathode electron gun is protected by adjusting the operating voltage and the parameters of the electron optical system of the electron gun to meet the needs of long-term stable operation.

[0045] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0046] The embodiment of the present application provides a high-power cold cathode electron gun protection system based on multi-point temperature measurement, including: a temperature measuring device, the temperature measuring device includes a plurality of temperature sensors, each temperature sensor is respectively connected to a different part of the electron gun; each temperature sensor is used to monitor the temperature signal of different parts of the electron gun respectively; a temperature detection and analysis system, the temperature detection and analysis system is connected to the temperature measuring device; the temperature detection and analysis system is used to receive the temperature signal, and output an adjustment signal of the working parameter corresponding to the electron gun according to the temperature signal; an electron gun control system, the electron gun control system is connected to the temperature detection and analysis system, and is used to receive the adjustment signal, and adjust the working parameter corresponding to the electron gun according to the adjustment signal, so that the temperature of the electron gun is maintained within a set range.

[0047] In some embodiments, the temperature measuring device includes a first temperature sensor, which is connected to the cathode water outlet pipe and is used to monitor the cathode water outlet pipe temperature signal; the temperature detection and analysis system is used to receive the cathode water outlet pipe temperature signal, and when the cathode water outlet pipe temperature signal exceeds a first preset range, outputs a high-voltage adjustment signal; the electron gun control system includes a high-voltage control system, which is used to receive the high-voltage adjustment signal and adjust the voltage.

[0048] In some embodiments, the temperature measuring device also includes a second temperature sensor, which is connected to the anode water outlet pipe and is used to monitor the temperature signal of the anode water outlet pipe; the temperature detection and analysis system is also used to receive the temperature signal of the anode water outlet pipe, and when the temperature signal of the anode water outlet pipe exceeds a second preset range, output a pre-focusing coil drive current adjustment signal; the electron gun control system also includes a pre-focusing control system, which is used to receive the pre-focusing coil drive current adjustment signal and adjust the pre-focusing coil current parameters.

[0049] In some embodiments, the temperature measuring device also includes a third temperature sensor, which is connected to the upper section of the electron gun and is used to monitor the temperature signal of the outer surface of the upper section of the electron gun; the temperature detection and analysis system is also used to receive the temperature signal of the outer surface of the upper section of the electron gun, and when the temperature signal of the outer surface of the upper section of the electron gun exceeds a third preset range, output a high-voltage adjustment signal; the electron gun control system includes a high-voltage control system, which is used to receive the high-voltage adjustment signal and adjust the voltage.

[0050] In some embodiments, the temperature measuring device also includes a fourth temperature sensor, which is connected to the beam guide channel water outlet pipe and is used to monitor the temperature signal of the beam guide channel water outlet pipe; the temperature detection and analysis system is also used to receive the temperature signal of the beam guide channel water outlet pipe, and when the temperature signal of the beam guide channel water outlet pipe exceeds a fourth preset range and the scanning coil is not working, outputs a main focusing coil drive current adjustment signal; the electron gun control system also includes a main focusing control system, which is used to receive the main focusing coil drive current adjustment signal and adjust the main focusing coil current parameters.

[0051] In some embodiments, the temperature measuring device also includes a fourth temperature sensor, which is connected to the beam guide channel water outlet pipe and is used to monitor the temperature signal of the beam guide channel water outlet pipe; the temperature detection and analysis system is also used to receive the temperature signal of the beam guide channel water outlet pipe, and when the temperature signal of the beam guide channel water outlet pipe exceeds a fourth preset range and the scanning coil is working, outputs a scanning coil drive current adjustment signal; the electron gun control system also includes a scanning control system, which is used to receive the scanning coil drive current adjustment signal and adjust the scanning coil current parameters.

[0052] In some embodiments, an alarm unit is also included, which is connected to the temperature detection and analysis system; the temperature detection and analysis system is also used to output an alarm signal after the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun does not reach the set range; the alarm unit is used to receive the alarm signal and issue an alarm.

[0053] In some embodiments, the temperature detection and analysis system is also used to set the high-voltage given signal to 0 when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun has not reached the set range; the high-voltage control system is also used to turn off the high-voltage output when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun has not reached the set range.

[0054] In some embodiments, it also includes a regulated DC power supply and a plurality of connection resistors; one end of each temperature sensor is connected to the regulated DC power supply through the connection resistor, and the other end is grounded.

[0055] In some embodiments, multiple operational amplifier circuits are also included; each operational amplifier circuit is respectively connected between a corresponding temperature sensor and a temperature detection and analysis system.

[0056] The present application relates to a high-power cold cathode electron gun protection system based on multi-point temperature measurement, specifically, a control circuit system that determines the state of the cold cathode electron beam by detecting the cathode cooling water temperature, the anode cooling water temperature, the electron gun upper surface temperature, and the beam guide channel temperature, and automatically adjusts the working voltage and electron optical system parameters to enable the cold cathode electron gun to maintain a high-power beam output state for a long time. In particular, it relates to a protection circuit system that ensures the long-term stable operation of the cold cathode electron gun in the environment of high-power electron beam physical vapor deposition and precious metal purification and smelting.

[0057] like Figure 1As shown, the high-power cold cathode electron gun system based on multi-point temperature measurement in this embodiment includes a temperature detection and analysis system 1, a high-voltage control system 2, a pre-focusing control system 3, a main focusing control system 4, a scanning control system 5, an alarm unit 17 and a temperature measuring device. The temperature detection and analysis system 1 adopts a DSP high-speed digital signal processor and is provided with multiple I / O ports to process input and output signals; the I / O signals of the temperature detection and analysis system include a cathode water outlet pipe temperature signal Uf1, an anode water outlet pipe temperature signal Uf2, an electron gun upper section outer surface temperature signal Uf3, a beam guide channel water outlet pipe temperature signal Uf4, a high-voltage given signal Uhvg1, a pre-focusing coil drive current given signal Ifg1, a main focusing coil drive current given signal Ifg2, a scanning coil drive current given signal Isg1, a high-voltage adjustment signal Uhvg11, a pre-focusing coil drive current adjustment signal Ifg11, a main focusing coil drive current adjustment signal Ifg21, and a scanning coil drive current adjustment signal Isg11.

[0058] The high voltage control system 2, the pre-focusing control system 3, the main focusing control system 4, and the scanning control system 5 are connected to the electron gun to control the operation of the electron gun, such as Figure 2 As shown. Specifically, the high-voltage control system 2 is an electron gun inverter power supply, which is connected to the electron gun through a high-voltage wire 603; the pre-focusing control system 3 is a pre-focusing coil driving circuit, which is connected to the pre-focusing coil 11; the main focusing control system 4 is a main focusing coil driving circuit, which is connected to the main focusing coil 12; the scanning control system 5 is a scanning coil driving circuit, which is connected to the scanning coil 14. The alarm unit 17 is a buzzer, which is connected to the temperature detection and analysis system 1. When the electron gun is abnormal, the temperature detection and analysis system 1 provides an alarm signal, and the buzzer sounds an alarm.

[0059] The temperature detection and analysis system 1 is connected to the high-voltage control system 2, and the high-voltage output of the cold cathode electron gun is adjusted by the high-voltage adjustment signal Uhvg11; the temperature detection and analysis system 1 is connected to the pre-focusing control system 3, and the magnitude of the pre-focusing coil driving current of the cold cathode electron gun is adjusted by the pre-focusing coil driving current adjustment signal Ifg11; the temperature detection and analysis system 1 is connected to the main focusing control system 4, and the magnitude of the main focusing coil driving current of the cold cathode electron gun is adjusted by the main focusing coil driving current adjustment signal Ifg21; the temperature detection and analysis system 1 is connected to the scanning control system 5, and the magnitude of the scanning coil driving current of the cold cathode electron gun is adjusted by the scanning coil driving current adjustment signal Isg11.

[0060] The temperature measuring device includes temperature sensor Rt1, temperature sensor Rt2, temperature sensor Rt3, and temperature sensor Rt4; the temperature measuring device is connected to the electron gun to monitor the temperature of key components of the electron gun. Figure 2As shown, the temperature sensor Rt1 is connected to the water-cooled cathode water outlet pipe 602, and is used to detect the temperature of the water-cooled cathode water outlet pipe port; the temperature sensor Rt2 is connected to the anode water outlet pipe 1002, and is used to detect the temperature of the anode water outlet pipe port; the temperature sensor Rt3 is connected to the electron gun upper section 9, and is used to detect the surface temperature of the electron gun upper section; the temperature sensor Rt4 is connected to the beam guide channel water outlet pipe 1302, and is used to detect the temperature of the beam guide channel water outlet pipe port.

[0061] Temperature sensors Rt1, Rt2, Rt3, and Rt4 are contact temperature measuring devices, such as thermal resistors. After the measuring end of the thermal resistor contacts the temperature measuring point of the electron gun, the temperature at the temperature measuring point can be continuously measured. The measuring end of the thermal resistor is fixed to the temperature measuring point of the electron gun by spot welding with a spot welder to prevent the thermal resistor from being displaced or even out of the temperature measuring area of ​​the electron gun, so as to avoid the thermal resistor failing to measure the temperature at the temperature measuring point of the electron gun or the measurement result being inaccurate. Furthermore, the thermal resistor is also wrapped with an insulating layer, which can be an insulating sleeve to protect the thermal resistor.

[0062] The temperature detection and analysis system 1 is provided with a data acquisition interface. Figure 1 As shown, one end of the temperature sensor Rt1 is connected to a +5V regulated DC power supply through a resistor R1, and the other end is connected to the ground. The change in the voltage at the connection end between the temperature sensor Rt1 and the resistor R1 reflects the change in the temperature at the temperature sensor detection location. The voltage at the connection end between the temperature sensor Rt1 and the resistor R1 outputs the measured temperature voltage signal Uf1 through the operational amplifier circuit IC1, and the temperature voltage signal Uf1 is input into the temperature detection and analysis system 1. The data acquisition interface is used to collect the temperature data detected by the temperature sensor Rt1, and transmit the temperature data to the temperature detection and analysis system 1.

[0063] The signal processing method of temperature sensors Rt2, Rt3, and Rt4 is the same as that of temperature sensor Rt1. The temperature sensors in this embodiment can respectively and independently collect the temperature data of each temperature measurement point of the electron gun at the same time, and transmit the temperature data measured by each temperature sensor to the temperature detection and analysis system 1 respectively and independently at the same time, so as to realize real-time temperature monitoring of multiple temperature measurement points of the electron gun; using the protection system in this embodiment, the temperature of key components of the cold cathode electron gun can be remotely and automatically monitored through the temperature detection and analysis system 1 when the cold cathode electron gun is working, and the temperature abnormality problem can be automatically controlled to restore the electron gun to normal working state. At the same time, if the temperature abnormality problem is not solved within the effective time, the temperature detection and analysis system 1 can shut down the system to stop the electron gun from working, and alarm for manual intervention. The protection system in this embodiment can realize continuous real-time temperature monitoring and control of the cold cathode electron gun.

[0064] Figure 3The following is a flow chart of the software program of the temperature detection and analysis system of the high-power cold cathode electron gun protection system based on multi-point temperature measurement according to an embodiment of the present application. The temperature detection and analysis system 1 is an intelligent system designed based on a DSP digital signal processor, which has the ability to process the collected temperature in real time, and can control other devices such as the high-voltage control system 2, the pre-focusing control system 3, the main focusing control system 4, the scanning control system 5, etc. in real time according to the temperature.

[0065] like Figure 3 As shown, the temperature detection and analysis system 1 is turned on and initialized, and the cold cathode electron gun starts to work normally. The temperature detection and analysis system 1 receives the electrical signal of the amplified temperature sensor through the I / O interface, and samples and converts the temperature data measured by the temperature sensor through the ADC digital-to-analog converter to determine the temperature change information at the temperature measurement point of the cold cathode electron gun. Specifically, according to the temperature-voltage comparison value of the temperature sensor corresponding to the corresponding temperature, it can be based on the table lookup method or the formula method. Specifically, the temperature monitoring and analysis system 1 adopts the table lookup method designed by the table lookup instruction of the DSP digital signal processor.

[0066] The temperature detection and analysis system 1 can process the temperature data obtained by real-time monitoring by the temperature measuring device to obtain a curve of the temperature at the temperature measuring point of the cold cathode electron gun changing with time. When multiple temperature measuring devices are used to monitor multiple temperature measuring points of the cold cathode electron gun, the temperature data at each temperature measuring point can be processed separately to obtain a curve of the temperature at each temperature measuring point changing with time.

[0067] The temperature detection and analysis system 1 monitors the temperature at each temperature measuring point of the cold cathode electron gun in real time, and determines whether the temperature at each temperature measuring point of the electron gun is within the normal temperature range. In addition, each temperature measuring point of the electron gun is provided with a different normal temperature range. When the temperature at each temperature measuring point of the electron gun is normal, the temperature information continues to be monitored; when the temperature at the temperature measuring point of the electron gun exceeds the normal temperature range, the temperature detection and analysis system 1 adjusts the electron gun control system corresponding to the temperature abnormal point according to the detection position of the temperature measuring point, sets multiple parameters of the proportional differential integral controller as a cooling parameter combination, and adjusts the parameters of the electron gun control system. According to the different positions of the temperature abnormal point, the corresponding adjustment time is set. During the adjustment time, the parameters are adjusted in real time according to the real-time temperature data until the electron gun returns to a normal working state; when the adjustment time is exceeded, the temperature at the temperature measuring point of the electron gun is still abnormal, the temperature detection and analysis system 1 cuts off the output of the electron gun, provides an alarm signal to the alarm unit 17, the buzzer alarms, and manual intervention is performed to troubleshoot.

[0068] Taking a thermal resistor as an example of a temperature measuring device, the working process of protecting a cold cathode electron gun by a high-power cold cathode electron gun protection system based on multi-point temperature measurement in an embodiment of the present application is specifically described below.

[0069] First, the data acquisition device is connected to the temperature detection and analysis system, wherein the data acquisition device can be an operational amplifier processing circuit, and the temperature detection and analysis system can be a DSP digital signal processor. Then, the end of the thermal resistor is connected to the operational amplifier processing circuit, and the measuring end of the thermal resistor is fixedly connected to the temperature measuring point of the electron gun through an electric welder.

[0070] Example 1

[0071] The temperature sensor Rt1 is connected to the water-cooled cathode outlet pipe 602 and is used to detect the temperature of the water-cooled cathode outlet pipe port. If the temperature detection and analysis system 1 detects that the temperature signal of the temperature sensor Rt1 becomes high and exceeds the rated water cooling temperature of 60°C, a high voltage mutation may occur, causing a sudden change in the beam power. The temperature detection and analysis system 1 controls the high-voltage control system 2 and intervenes through the voltage reduction strategy. After the set adjustment time of 10s, it is detected that the temperature signal of the temperature sensor Rt1 returns to the normal range and the cold cathode electron gun works normally; otherwise, the temperature detection and analysis system 1 provides an alarm signal to the alarm unit 17, the buzzer alarms, and the high-voltage given signal Uhvg11 is set to "0", and the high-voltage output is turned off through the high-voltage control system 2, and the fault is eliminated by manual intervention.

[0072] The voltage reduction strategy is that the temperature detection and analysis system 1 gives a high-voltage adjustment signal Uhvg11 to control the high-voltage control system 2 to turn off the high voltage. The high-voltage turning-off time can be adjusted according to the maximum power set by the current electron gun. After the high-voltage turning-off time ends, the high voltage is started and the high-voltage soft start time is set to prevent voltage output overshoot. At the same time, the high voltage and beam current values ​​are detected. If the high voltage drops and the output beam current changes suddenly, the above voltage reduction process is repeated until the electron gun resumes normal operation.

[0073] Example 2

[0074] The temperature sensor Rt2 is connected to the anode outlet pipe 1002 and is used to detect the temperature of the anode outlet pipe port. If the temperature detection and analysis system 1 detects that the temperature signal of the temperature sensor Rt2 becomes higher and exceeds the rated water cooling temperature of 50°C, the pre-focusing parameter adjustment may be inappropriate, causing a large number of electrons to be intercepted by the anode. The temperature detection and analysis system 1 controls the pre-focusing control system 3, and adjusts it by increasing or decreasing the pre-focusing coil current parameter. After the set adjustment time of 30s, it is detected that the temperature signal of the temperature sensor Rt2 returns to the normal range, and the cold cathode electron gun works normally; otherwise, the temperature detection and analysis system 1 provides an alarm signal to the alarm unit 17, the buzzer alarms, and the Uhvg11 signal is set to "0", and the high-voltage output is turned off through the high-voltage control system 2, and the fault is eliminated by manual intervention.

[0075] The pre-focusing coil driving current adjustment strategy is that the temperature detection and analysis system 1 gives priority to the pre-focusing coil driving current adjustment signal Ifg11 to control the pre-focusing control system 3, calculates the cooling parameter combination according to the temperature difference, sets the control parameters of the pid controller according to the cooling parameter combination to increase the pre-focusing coil driving current at a certain ratio, and samples the anode outlet pipe temperature every 0.1 seconds, and calculates the temperature change rate within this time interval. When the temperature change rate decreases, the driving current growth rate is adjusted according to the current temperature change rate until the anode temperature returns to the normal range and tends to be stable; when the temperature change rate increases, the driving current reduction rate is adjusted according to the current temperature change rate until the anode temperature returns to the normal range and tends to be stable.

[0076] Example 3

[0077] The temperature sensor Rt3 is connected to the upper section 9 of the electron gun and is used to detect the surface temperature of the upper section of the electron gun. If the temperature detection and analysis system 1 detects that the temperature signal of the temperature sensor Rt3 becomes high and exceeds the rated water cooling temperature of 30°C, a sudden change in the airflow may occur, and discharge occurs between the outer surface of the connecting ring and the inner surface of the upper section of the electron gun. The temperature detection and analysis system 1 controls the high-voltage control system 2 and intervenes by reducing the beam current through a voltage reduction strategy. After the set adjustment time of 30s, it is detected that the temperature signal of the temperature sensor Rt3 returns to the normal range and the cold cathode electron gun works normally; otherwise, the temperature detection and analysis system 1 provides an alarm signal to the alarm unit 17, the buzzer alarms, and the high-voltage given signal Uhvg11 is set to "0", and the high-voltage output is turned off through the high-voltage control system 2. The airflow control system is checked by manual intervention to eliminate the fault.

[0078] The voltage reduction strategy is that the temperature detection and analysis system 1 gives a high-voltage adjustment signal Uhvg11 to control the high-voltage control system 2, sets the voltage setting signal of the inverter power supply to 50% of the current set value, and quickly adjusts the final output high voltage through the control circuit to respond quickly. At the same time, the beam current value after voltage adjustment is detected, and the beam current is determined to be within the normal range according to the current high-voltage value and gas flow. When the beam current value is within the normal range, it means that the sudden change of airflow caused by high-voltage discharge is excluded, and the temperature detection and analysis system 1 adjusts the boost parameter to gradually increase the high-voltage output of the high-voltage control system 2 until the normal power of the electron gun is restored; when the beam current value is not within the normal range, it means that the sudden change of airflow caused by high-voltage discharge still exists, and the temperature detection and analysis system 1 adjusts the voltage reduction parameter to gradually reduce the high-voltage output of the high-voltage control system 2 until the beam current is restored to the beam current value corresponding to the current voltage, and then gradually increases the high-voltage output until the normal power of the electron gun is restored.

[0079] Example 4

[0080] The temperature sensor Rt4 is connected to the water outlet pipe 1302 of the beam guide channel, and is used to detect the temperature of the water outlet pipe port of the beam guide channel. The temperature detection and analysis system 1 detects that the temperature signal of the temperature sensor Rt4 becomes high, exceeding the rated water cooling temperature of 60°C. At this time, it checks whether the scanning coil 14 is working. If the scanning coil is not working, it may be that the current parameters of the main focusing coil are not appropriate, so that the beam cross-sectional area inside the beam guide channel is too large, and a large number of electrons are intercepted by the beam guide channel, causing the temperature of the beam guide channel to rise sharply. The temperature detection and analysis system 1 controls the main focusing control system 4, and reduces the beam cross-sectional area inside the beam guide channel by adjusting the current parameters of the main focusing coil. After the set adjustment time of 30s, it is detected that the temperature signal of the temperature sensor Rt4 returns to the normal range, and the cold cathode electron gun works normally; otherwise, the temperature detection and analysis system 1 provides an alarm signal to the alarm unit 17, the buzzer alarms, and the high-voltage given signal Uhvg11 is set to "0", and the high-voltage output is turned off through the high-voltage control system 2. The main focusing coil 12 and the main focusing control system 4 are checked by manual intervention to eliminate the fault.

[0081] The main focusing coil driving current adjustment strategy is that the temperature detection and analysis system 1 gives priority to the main focusing coil driving current adjustment signal Ifg21 to control the main focusing control system 4, calculates the cooling parameter combination according to the temperature difference, sets the control parameters of the pid controller according to the cooling parameter combination to increase the main focusing coil driving current at a certain ratio, and samples the temperature of the water outlet pipe attachment of the beam guide channel every 0.1 seconds, and calculates the temperature change rate within this time interval. When the temperature change rate decreases, the driving current growth rate is adjusted according to the current temperature change rate until the temperature of the water outlet pipe attachment of the beam guide channel returns to the normal range and tends to be stable; when the temperature change rate increases, the driving current reduction rate is adjusted according to the current temperature change rate until the temperature of the water outlet pipe attachment of the beam guide channel returns to the normal range and tends to be stable.

[0082] Example 5

[0083] The temperature sensor Rt4 is connected to the water outlet pipe 1302 of the beam guide channel, and is used to detect the temperature of the water outlet pipe port of the beam guide channel. The temperature detection and analysis system 1 detects that the temperature signal of the temperature sensor Rt4 becomes high, exceeding the rated water cooling temperature of 60°C. At this time, it checks whether the scanning coil 14 is working. If the scanning coil is working, the current amplitude passing through the scanning coil may be too large, causing the electron beam scanning to hit the inner surface of the lower section of the beam guide channel during the scanning peak current stage. The temperature detection and analysis system 1 controls the scanning control system 5, and by reducing the current amplitude of the scanning coil, after the set adjustment time of 30s, it is detected that the temperature signal of the temperature sensor Rt4 is restored to the normal range, and the cold cathode electron gun works normally; otherwise, the temperature detection and analysis system 1 provides an alarm signal to the alarm unit 17, the buzzer alarms, and the high-voltage given signal Uhvg11 is set to "0", and the high-voltage output is turned off through the high-voltage control system 2. The scanning coil 14 and the scanning control system 5 are checked by manual intervention to eliminate the fault.

[0084] The scanning coil reduction strategy is that the temperature detection and analysis system 1 gives the scanning coil drive current adjustment signal Isg11 to control the scanning control system 5, calculates the cooling parameter combination according to the temperature difference, sets the control parameters of the pid controller according to the cooling parameter combination to reduce the drive current of the scanning coil at a certain ratio, and samples the temperature of the water outlet pipe attachment of the beam guide channel every 0.1 seconds, and calculates the temperature change rate within this time interval. When the temperature change rate decreases, the drive current reduction rate is adjusted according to the current temperature change rate until the temperature of the water outlet pipe attachment of the beam guide channel returns to the normal range and tends to be stable.

[0085] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0086] The high-power cold cathode electron gun protection system based on multi-point temperature measurement provided in the embodiment of the present application can effectively grasp the state of the internal beam of the cold cathode electron gun during the actual use of the electron gun by adopting multi-point temperature measurement to detect the temperature of the key components of the high-power cold cathode electron gun, and has practical value; according to the temperature detected by the multi-point temperature measurement, the operating voltage and the electron optical system parameters of the electron gun are automatically adjusted, so as to protect the high-power cold cathode electron gun, improve the stability and reliability of the long-term operation of the high-power cold cathode electron gun, and improve the processing quality of the cold cathode electron beam; through the temperature detection and analysis system, the temperature abnormal points of the key components of the electron gun can be quickly and accurately found and the optimal adjustment of the parameters can be achieved, thereby reducing the number of manual interventions and avoiding the shortcomings of slow manual adjustment and low precision.

[0087] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned 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. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0088] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A high-power cold cathode electron gun protection system based on multi-point temperature measurement, characterized in that: include: A temperature measuring device, wherein the temperature measuring device comprises a plurality of temperature sensors, each of which is connected to a different part of the electron gun; each of the temperature sensors is used to monitor the temperature signal of a different part of the electron gun; A temperature detection and analysis system, the temperature detection and analysis system is connected to the temperature measuring device; the temperature detection and analysis system is used to receive the temperature signal and output an adjustment signal of the working parameter corresponding to the electron gun according to the temperature signal; The electron gun control system is connected to the temperature detection and analysis system, and is used to receive the adjustment signal and adjust the corresponding working parameters of the electron gun according to the adjustment signal to maintain the temperature of the electron gun within a set range.

2. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: The temperature measuring device comprises a first temperature sensor, which is connected to the cathode water outlet pipe and is used to monitor the temperature signal of the cathode water outlet pipe; The temperature detection and analysis system is used to receive the cathode water outlet pipe temperature signal, and output a high-voltage adjustment signal when the cathode water outlet pipe temperature signal exceeds a first preset range; The electron gun control system includes a high voltage control system, and the high voltage control system is used to receive the high voltage adjustment signal and adjust the voltage.

3. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: The temperature measuring device further comprises a second temperature sensor, which is connected to the anode water outlet pipe and is used to monitor the temperature signal of the anode water outlet pipe; The temperature detection and analysis system is also used to receive the temperature signal of the anode water outlet pipe, and output a pre-focusing coil drive current adjustment signal when the temperature signal of the anode water outlet pipe exceeds a second preset range; The electron gun control system further comprises a pre-focusing control system, which is used to receive the pre-focusing coil driving current adjustment signal and adjust the pre-focusing coil current parameters.

4. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: The temperature measuring device further comprises a third temperature sensor, which is connected to the upper section of the electron gun and is used to monitor the temperature signal of the outer surface of the upper section of the electron gun; The temperature detection and analysis system is also used to receive a temperature signal of the outer surface of the upper section of the electron gun, and output a high-voltage adjustment signal when the temperature signal of the outer surface of the upper section of the electron gun exceeds a third preset range; The electron gun control system includes a high voltage control system, and the high voltage control system is used to receive the high voltage adjustment signal and adjust the voltage.

5. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: The temperature measuring device further includes a fourth temperature sensor, which is connected to the water outlet pipe of the beam guiding channel and is used to monitor the temperature signal of the water outlet pipe of the beam guiding channel; The temperature detection and analysis system is further used to receive a temperature signal of the water outlet pipe of the beam guiding channel, and output a main focusing coil driving current adjustment signal when the temperature signal of the water outlet pipe of the beam guiding channel exceeds a fourth preset range and the scanning coil is not working; The electron gun control system further comprises a main focus control system, which is used to receive the main focus coil driving current adjustment signal and adjust the main focus coil current parameters.

6. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: The temperature measuring device further includes a fourth temperature sensor, which is connected to the water outlet pipe of the beam guiding channel and is used to monitor the temperature signal of the water outlet pipe of the beam guiding channel; The temperature detection and analysis system is further used to receive a temperature signal of the water outlet pipe of the beam guiding channel, and output a scanning coil driving current adjustment signal when the temperature signal of the water outlet pipe of the beam guiding channel exceeds a fourth preset range and the scanning coil is working; The electron gun control system further comprises a scanning control system, which is used to receive the scanning coil driving current adjustment signal and adjust the scanning coil current parameters.

7. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: It also includes an alarm unit, which is connected to the temperature detection and analysis system; The temperature detection and analysis system is also used to output an alarm signal when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun does not reach a set range; The alarm unit is used to receive the alarm signal and issue an alarm.

8. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 2, characterized in that: The temperature detection and analysis system is also used to set the high voltage given signal to 0 when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun does not reach the set range; The high voltage control system is also used to turn off the high voltage output when the electron gun control system adjusts the working parameters corresponding to the electron gun for a preset period of time and the temperature of the electron gun does not reach a set range.

9. The high-power cold cathode electron gun protection system based on multi-point temperature measurement as claimed in claim 1, characterized in that: It also includes a voltage-stabilized DC power supply and a plurality of connection resistors; one end of each of the temperature sensors is connected to the voltage-stabilized DC power supply through the connection resistor, and the other end is grounded.

10. The high-power cold cathode electron gun protection system based on multi-point temperature measurement according to claim 1, characterized in that: It also includes a plurality of operational amplifier circuits; each of the operational amplifier circuits is respectively connected between the corresponding temperature sensor and the temperature detection and analysis system.

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