High power density water-cooled anode filament cathode emission performance testing device

Abstract

The utility model provides a high power density water -cooled anode's filamentous cathode emission performance test device relates to vacuum electron device field. Including: anode body and anode cylinder, wherein, anode cylinder is hollow cylindrical structure, wherein outside end face is connected to anode body, remaining outside surface is contacted with cooling water in anode body, and the inside surface corresponds with filamentous cathode to test the emission performance of the cathode. The anode of this anode cylinder is hollow cylindrical structure, and the gas permeability of the airtight space between anode cylinder and anode body is very low, so that the cathode emission test device can test the emission performance of filamentous cathode. Meanwhile, the outside surface of anode cylinder is contacted with cooling water, so that the electron of higher power density can be received, and the refractory metal evaporation of anode cylinder is not easy to cause, and the anode is damaged. In addition, the device structure is simple, and convenient operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vacuum electron devices, and in particular to a filament cathode emission testing device of a high-power-density water-cooled anode. BACKGROUND

[0002] Vacuum electron devices are widely used in radar, satellite communication, electron accelerator, global positioning, controllable thermonuclear fusion and future military high-power microwave weapons due to their unique functions and superior performance. In particular, in the case of high power and high frequency, vacuum electron devices are irreplaceable by other devices. Modern high-tech microwave devices constantly put forward new development requirements for the power, frequency, bandwidth and other working characteristics of microwave signals. These requirements mainly include higher frequency, greater power, wider bandwidth, higher efficiency and new working characteristics, thereby putting forward new challenges and development opportunities for the development of vacuum electron devices and related technologies.

[0003] The cathode for electron emission is the most core part in a vacuum electron device, and its performance will directly affect the output performance and service life of the microwave source, and further affect the performance and service life of the satellite and high-power microwave device. Therefore, the cathode emission performance is an important index of the vacuum electron device. At present, due to the limitation of the anode for cathode emission testing in the vacuum electron device, the filament cathode emission performance testing power is low, and the electron power density received by the anode cannot be too high. Too high electron power density will cause the anode to overheat, thereby affecting the cathode emission performance and causing damage to the anode. SUMMARY

[0004] (I) Technical problems to be solved

[0005] In view of the above technical problems, the present application provides a high-power-density water-cooled anode and a filament cathode emission testing device to solve the above technical problems.

[0006] (II) Technical solutions

[0007] On one hand, the present invention provides a device for testing the emission performance of a filament cathode of a vacuum electronic device with a high power density water-cooled anode, comprising: an anode body (9) and an anode cylinder (8), wherein the anode body (9) is a cylindrical structure with a sealed bottom, and the anode cylinder (8) is a cylindrical structure with two ends open, the anode cylinder (8) passes through the lower part of the anode body (9), and the central axes of the anode cylinder (8) and the anode body (9) intersect vertically; the outer side surfaces of the two ends of the anode cylinder (8) are connected and sealed to the anode body (9), and the filament cathode (7) coaxially passes through the anode cylinder (8) to test the emission performance of the filament cathode of the vacuum electronic device. The emission performance of the cathode (7) is improved, and the filament cathode (7) is not in contact with the anode tube (8); a coaxial water inlet pipe (2) is provided at the upper end of the anode body (9), and a water outlet (3) is provided on the upper wall of the anode body (9), so that cooling water enters from the water inlet pipe (2) and exits from the water outlet (3) on the side, and the anode tube (8) is immersed in the cooling water in the anode body (9); both ends of the filament cathode (7) coaxially passing through the anode tube (8) are connected to an electrode (4), and each electrode (4) is fixed by an insulating ceramic (5) and then by an electrode flange (6).

[0008] The outer diameter of the anode cylinder (8) is smaller than the inner diameter of the anode body (9).

[0009] Optionally, the seal between the anode body (9) and the anode cylinder (8) has a gas leakage rate of less than 1×10 -9 Pa.m 3 / s.

[0010] Optionally, the material of the anode cylinder (8) is a metal or alloy material such as tungsten or molybdenum with low saturated vapor pressure and high melting point.

[0011] Optionally, the material of the anode body (9) is a metal material with high thermal conductivity, easy processing and low price, such as copper, stainless steel or other alloys.

[0012] (3) Beneficial effects

[0013] The present disclosure provides a high-power density water-cooled anode and filament cathode emission test device, which has the following beneficial effects: the anode tube in the anode of the cathode emission test device is a cylindrical structure, the air permeability of the enclosed space between the anode tube and the anode body is very low, and the outer side of the anode tube (8) is in contact with the cooling water, so that it can receive electrons with a high power density, and it is not easy to cause the refractory metal of the anode tube (8) to evaporate and cause damage to the anode. The emission performance of the filament cathode can be tested, which is conducive to receiving electrons with a high power density, and will not cause the refractory metal to evaporate, neither affecting the cathode emission performance nor causing damage to the anode, and has high economic value. In addition, the device has a simple structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, which are incorporated herein and constitute a part of this specification, illustrate embodiments consistent with the present disclosure, and together with the description serve to explain the principles of the present disclosure. In which:

[0015] Figure 1 The figure schematically shows an anode structure diagram for testing the emission performance of a filament cathode of a vacuum electron device according to an exemplary embodiment of the present disclosure;

[0016] Figure 2 Schematically shows a side view of an anode structure for testing the emission performance of a filament cathode of a vacuum electronic device according to an exemplary embodiment of the present disclosure;

[0017] Figure 3 The flowchart of the method for preparing an anode for testing the emission performance of a filament cathode of a vacuum electronic device according to an exemplary embodiment of the present disclosure is schematically shown;

[0018] 1-water inlet 2-water inlet pipe 3-water outlet 4-electrode 5-insulating ceramic 6-electrode flange 7-filament cathode 8-anode cylinder 9-anode body;

[0019] Figure 4 The volt-ampere characteristic curves of La-W cathode measured at different temperatures;

[0020] Figure 5 This is the volt-ampere characteristic curve of the La-Mo cathode measured at different temperatures in the literature. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure. Example 1

[0022] An embodiment of the present disclosure provides an anode for testing the emission performance of a filament cathode of a vacuum electron device. Figure 1 The structure of an anode for testing the emission performance of a filament cathode of a vacuum electron device according to an exemplary embodiment of the present disclosure is schematically shown. Figure 2 The figure schematically shows a side view of an anode for testing the emission performance of a filament cathode of a vacuum electron device according to an exemplary embodiment of the present disclosure, as shown in FIG. Figure 1 and Figure 2 As shown, the anode may include, for example:

[0023] The anode body 9 has a water inlet pipe 2 inside, a water inlet 1 and a water outlet 3 on the wall, an electrode flange 6, insulating ceramic and an electrode 4 on the flange 6, and a filament cathode 7 fixed on the electrode 4.

[0024] During the test of the filament cathode emission performance, cooling water enters the water inlet pipe 2 from the water inlet 1 and then flows out from the water outlet 3. The material of the anode body 9 is selected from a metal that is easy to process, easy to weld, low in price and has high thermal conductivity. The thermal conductivity of the material can be, for example, higher than the third preset value of the metal. The third preset value can be, for example, 0.5 W / cm.K (at a temperature of 100°C). That is, the material of the anode body 9 selected in this embodiment has a thermal conductivity higher than 0.5W / cm.K at a temperature of 100°C, and this disclosure does not impose any restrictions. In a feasible manner of this embodiment, for example, stainless steel or oxygen-free copper can be used. Preferably, oxygen-free copper is used to prepare the anode body 9, and this disclosure does not impose any restrictions.

[0025] The cylindrical anode tube 8 is a hollow cylindrical structure, with the outer side surfaces of its two ends connected to the anode body 9, forming a sealed space between the anode tube 8 and the anode body 9. Its inner side corresponds to the filament cathode 7 to test the emission performance of the cathode 7. In one feasible embodiment of the present disclosure, the anode tube 8 can be a cylindrical structure, so that the emission current of the filament cathode can be tested, which is not limited by the present disclosure.

[0026] A sealed space is formed between the anode body 9 and the anode cylinder 8, and the air permeability of the sealed space is as small as possible. In a feasible mode of this embodiment 1, the air permeability of the sealed space can be, for example, less than 1×10 -9 Pa.m 3 / s, the specific air permeability can be set according to actual needs and is not limited in this disclosure.

[0027] The material of the anode cylinder 8 can be selected from metal or alloy materials with high melting point, low saturated vapor pressure and low price. The saturated vapor pressure of the material can be lower than the first preset value, while the melting point can be higher than the second preset value, wherein the first preset value can be 10 -9 Pa (under the condition of a temperature of 600°C), the second preset value can be, for example, 1000°C, which is not limited in this disclosure. In a feasible manner of this embodiment 1, the anode cylinder 8 can be made of, for example, molybdenum or tungsten, or an alloy thereof, such as a rhenium-tungsten alloy, a ruthenium-molybdenum alloy, or a tungsten-molybdenum alloy, which is not limited in this disclosure.

[0028] This embodiment provides an anode for testing the emission performance of a filament cathode in a vacuum electron device. The anode tube has a polyhedral structure, and the air permeability of the enclosed space between the anode tube and the anode body is very low, allowing the emission performance of the filament cathode to be tested on the anode. Furthermore, by rationally designing the materials of the anode body and the anode tube, testing efficiency is further improved. Furthermore, the device has a simple structure and is easy to operate.

[0029] Figure 3 A flow chart of a method for preparing an anode for testing emission performance of a filamentary cathode of a vacuum electronic device according to an exemplary embodiment of the present disclosure is schematically shown. The method may include operations S301 - 302 .

[0030] S301, preparing the anode body 9 and the anode cylinder 8 with a cylindrical structure.

[0031] In a feasible approach of this embodiment, the anode body 9 is made of a metal that is easy to process, easy to weld, inexpensive, and has high thermal conductivity, and the anode cylinder 8 is made of a metal or alloy material that has a high melting point, low saturated vapor pressure, and is inexpensive. A water inlet pipe 2 is provided inside the anode body 9, and a water inlet 1 and a water outlet 3 are provided on the wall of the anode body 9.

[0032] S302 , connecting the outer side surfaces of both ends of the anode cylinder 8 to the anode body 9 , so that a sealed space is formed between the anode cylinder 8 and the anode body 9 .

[0033] In a feasible mode of this embodiment 1, the anode cylinder 8 and the anode body 9 are welded by welding. The welding method can be, for example, electron beam welding, laser welding, brazing, etc. It is necessary to ensure that the bottom metal sheet of the anode and the anode body are tightly connected, and the gas leakage rate is less than 1×10 -9 Pa.m 3 / s. The preferred welding method is brazing. Example 2

[0034] The method for testing the emission performance using the above device comprises the following steps:

[0035] Step 1. Install the water-cooled anode with welded filament cathode on the quartz bell jar;

[0036] Step 2. Vacuum to 1.0x10 -6 pa;

[0037] Step 3: Pass cooling water and start to slowly heat the filament cathode. The vacuum should not be less than 5.0x10 -6 pa;

[0038] Step 4. When the cathode is heated to the corresponding temperature, such as 1600°C, start to slowly increase the anode voltage, during which the vacuum should not be less than 5.0x10 -6 pa;

[0039] Step 5. After the anode voltage is increased to the maximum (different voltages are set according to the test performance), it is kept for a period of time, for example, the voltage is 500V and it stays for about 5 hours. At this time, the maximum power of the anode receiving electron bombardment can reach 500W, and the power density can reach 1000W / cm 2 , such a high power density, if there is no water-cooled anode or a water-cooled anode made of general materials is used, it will cause evaporation or even melting;

[0040] Step 6. After the cathode emission stabilizes, start recording the values ​​of the anode voltage and emission current to complete the filament cathode emission performance test.

[0041] The volt-ampere characteristic curves of La-W cathode measured at different temperatures using the above method are shown in Figure 4 ;

[0042] Figure 5 This is the volt-ampere characteristic curve of the La-Mo cathode measured at different temperatures in the literature.

[0043] Compared with the La-Mo cathode with good performance that has been widely studied, the electron emission performance of the La-W cathode tested by the present device in Example 2 is also relatively stable, and the test results are accurate.

[0044] For details not covered in this embodiment, please refer to the above-mentioned embodiment of the anode structure, which will not be repeated here.

[0045] The preparation method of this embodiment is simple, and the prepared anode can be used to measure the emission performance of the filament cathode.

[0046] An embodiment of the present application further provides a cathode emission test device. The cathode emission test device includes an anode that adopts the anode described in the above embodiment. The cathode emission test device has high testing efficiency.

[0047] It will be appreciated by those skilled in the art that although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present application, it will be appreciated by those skilled in the art that various changes in form and details may be made to the present application without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents. Therefore, the scope of the present application should not be limited to the above-described embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

Claims

1. A device for testing the emission performance of a filament cathode of a vacuum electronic device using a high power density water-cooled anode, characterized in that: include: An anode body (9) and an anode cylinder (8), wherein the anode body (9) is a cylindrical structure with a sealed bottom, and the anode cylinder (8) is a cylindrical structure with two ends open. The anode cylinder (8) passes through the lower part of the anode body (9), and the central axes of the anode cylinder (8) and the anode body (9) intersect vertically; the outer side surfaces of the two ends of the anode cylinder (8) are connected and sealed with the anode body (9), and the filament cathode (7) coaxially passes through the anode cylinder (8) to test the emission performance of the cathode (7), and the filament cathode (7) and the anode cylinder (8) are connected. ) do not contact; a coaxial water inlet pipe (2) is provided at the upper end of the anode body (9), and a water outlet (3) is provided on the upper wall of the anode body (9), so that cooling water enters from the water inlet pipe (2) and exits from the water outlet (3) on the side, and at the same time the anode cylinder (8) is immersed in the cooling water in the anode body (9); both ends of the filament cathode (7) coaxially passing through the anode cylinder (8) are connected to an electrode (4), and each electrode (4) is fixed by an insulating ceramic (5) and then by an electrode flange (6).

2. The device according to claim 1, characterized in that The outer diameter of the anode cylinder (8) is smaller than the inner diameter of the anode body (9).

3. The device according to claim 1, characterized in that The air leakage rate of the seal between the anode body (9) and the anode cylinder (8) is less than 1×10 -9 Pa.m 3 / s.

4. The device according to claim 1, characterized in that The anode cylinder (8) is made of tungsten, molybdenum metal or alloy material with low saturated vapor pressure and high melting point.

5. The device according to claim 1, characterized in that The material of the anode body (9) is copper or stainless steel.

6. A method for testing emission performance using the device according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: Step 1. Install the water-cooled anode with welded filament cathode on the quartz bell jar; Step 2. Vacuum to 1.0x10 -6 pa; Step 3: Pass cooling water and start to slowly heat the filament cathode. The vacuum should not be less than 5.0x10 -6 pa; Step 4. When the cathode is heated to 1600℃, start to slowly increase the anode voltage, during which the vacuum should not be less than 5.0x10 -6 pa; Step 5. After the anode voltage is increased to the maximum, it is kept for 5 hours. At this time, the maximum power of the anode receiving electron bombardment can reach 500W, and the power density can reach 1000W / cm 2 , such a high power density, if there is no water-cooled anode or a water-cooled anode made of general materials is used, it will cause evaporation or even melting; Step 6. After the cathode emission stabilizes, start recording the values ​​of the anode voltage and emission current to complete the filament cathode emission performance test.

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