A method for testing insulating ceramics, X-ray tubes and secondary electrons

Abstract

The present invention belongs to the technical field of X-ray equipment, and discloses an insulating ceramic, an X-ray tube and a method for testing secondary electrons. The insulating ceramic is installed on the X-ray tube, and the X-ray tube comprises a tube shell, a cathode assembly and an anode assembly. The anode assembly is rotatably penetrated at one end of the tube shell, and the cathode assembly is installed at the other end of the tube shell. The insulating ceramic comprises a ceramic body and a metal probe. The outer peripheral wall of the ceramic body comprises a conical surface, and the small end of the conical surface is sealed and connected to a supporting assembly of the anode assembly, and the large end of the ceramic body is sealed and connected to the tube shell. There are multiple metal probes, and the multiple metal probes are arranged at intervals in the circumferential direction around the ceramic body. Each metal probe is penetrated in the conical surface, and each metal probe is used to be connected to an external secondary electron detection device, and the other end of the metal probe is used to collect secondary electrons in the tube shell.

Description

Technical Field

[0001] The present invention relates to the field of X-ray technology, and in particular to a testing method for insulating ceramics, an X-ray tube and secondary electrons. Background Art

[0002] During high-power testing and operation of X-ray tubes, the main causes of sparking include potential difference and electronic activity. In traditional double-ended X-ray tubes, the rotating anode has a high voltage of 60kV-70kV, while the potential of the tube shell is zero. Insulating ceramics are required between the two to maintain the potential difference. When the insulating material is not able to withstand enough voltage, the potential difference between the tube shell and the outer wall of the rotating anode will cause sparking. There are many types of electronic activities in X-ray tubes, among which secondary electron multiplication and field emission can cause sparking. Since the secondary electron coefficient on the surface of insulating ceramics is greater than 1 (usually between 6 and 10), once the secondary electrons and field emission electrons bombard the strong electric field area on the surface of the insulating ceramics, a large number of secondary electrons will be generated on the surface of the insulating ceramics, resulting in a positive charge area close to the surface of the tube shell, further increasing the current of field emission, and causing the insulating ceramics or glass to break down.

[0003] In the field of electric vacuum, the traditional method of suppressing secondary electron multiplication is to coat a functional film on the ceramic surface. For example, in the field of traveling wave tubes and electron linear accelerators, in order to suppress the secondary electron multiplication effect of ceramic window components, a titanium nitride film of about 10nm is usually coated on the vacuum side of the ceramic window. The components after titanium nitride coating cannot be brazed again because high temperature will destroy the titanium nitride film. This method is not applicable to X-ray tubes.

[0004] Therefore, it is urgent to propose an insulating ceramic and an X-ray tube that can suppress secondary electron multiplication. Summary of the invention

[0005] The first object of the present invention is to provide an insulating ceramic which can suppress the secondary electron multiplication phenomenon and reduce the probability of sparking inside the X-ray tube.

[0006] A second object of the present invention is to provide an X-ray tube that can suppress the secondary electron multiplication phenomenon and reduce the probability of sparks inside the X-ray tube.

[0007] The third object of the present invention is to provide a secondary electron testing method, which can monitor the number of secondary electrons generated in the X-ray tube in real time during the operation of the X-ray tube, and can promptly prompt the user when sparking occurs.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] The present invention discloses an insulating ceramic, which is installed on an X-ray tube. The X-ray tube comprises a tube shell, a support assembly, a cathode assembly and an anode assembly. The anode assembly is rotatably inserted into the support assembly, and the cathode assembly and the support assembly are respectively installed at two ends of the tube shell. The insulating ceramic comprises: a ceramic body, the outer peripheral wall of the ceramic body comprises a conical surface, and the small end of the conical surface is sealed and connected to the support assembly of the anode assembly, and the large end of the ceramic body is sealed and connected to the tube shell; a metal probe, wherein the metal probes are multiple, and the multiple metal probes are arranged at intervals in the circumferential direction around the ceramic body, each of the metal probes is inserted into the conical surface, and each of the metal probes is used to be connected to an external secondary electron detection device, and the other end of the metal probe is used to collect secondary electrons in the tube shell.

[0010] In some embodiments, a creepage structure is provided on at least one of the inner side wall, the outer side wall and the end surface away from the tube shell of the insulating ceramic, and the creepage structure is used to increase the creepage distance of the insulating ceramic.

[0011] In some specific embodiments, the creepage structure includes a plurality of convex rings, which are arranged at intervals on at least one of the inner side wall, the outer side wall and the end surface away from the tube shell of the insulating ceramic, or:

[0012] The creepage structure comprises a plurality of grooves, and the plurality of grooves are arranged at intervals on at least one of the inner side wall, the outer side wall and the end surface away from the tube shell of the insulating ceramic.

[0013] In some embodiments, the ceramic body includes a first sealing ring, a connecting sleeve and a second sealing ring connected in sequence, the outer peripheral wall of the connecting sleeve is the conical surface, and the first sealing ring is sealed to the supporting assembly, and the second sealing ring is sealed to the tube shell.

[0014] In some specific embodiments, the inner hole of the connecting sleeve is a straight hole, the outer diameter of the first sealing ring is 40mm-70mm, the outer diameter of the second sealing ring is 80mm-120mm, the total height of the connecting sleeve is 20mm-60mm, the height of the second sealing ring is 15mm-30mm, and the diameter of the inner hole is 20mm-60mm.

[0015] In some specific embodiments, the insulating ceramic further includes an external connecting tube, one end of which is sealed to the second sealing ring, the other end of which is sealed to the tube shell, and the inner side wall of which is spaced apart from the anode assembly.

[0016] In some specific embodiments, the insulating ceramic further includes an inner connecting tube, one end of which is sealingly connected to the first sealing ring, and the other end of which is sealingly connected to the supporting assembly.

[0017] In some more specific embodiments, the inner connecting tube has a connecting sealing edge that is in contact with the outer peripheral wall of the first sealing ring.

[0018] The present invention also discloses an X-ray tube, comprising a tube shell, a cathode assembly, an anode assembly and the insulating ceramic mentioned above, wherein a support assembly is provided in the tube shell, the anode assembly is rotatably mounted on the support assembly, the anode assembly and the cathode assembly are respectively located at two ends of the tube shell, and the insulating ceramic is sealed and connected to the tube shell and the support assembly.

[0019] The present invention also discloses a secondary electron testing method, which is used to detect whether secondary electrons exist inside the tube shell of the X-ray tube mentioned above; during the testing process, the tube shell is grounded, one end of the metal probe of the insulating ceramic is connected to a secondary electron detection device, and the secondary electron detection device is connected to a DC bias power supply; wherein: if the current value detected by the secondary electron detection device is not zero, then secondary electrons exist inside the tube shell of the X-ray tube; if the current detected by the secondary electron detection device is greater than a preset value, then sparking occurs inside the tube shell of the X-ray tube.

[0020] The beneficial effects of the insulating ceramic of the present invention are as follows: since a metal probe is provided on the insulating ceramic, the structure is very simple, and in actual operation, the metal probe is electrically connected to a secondary electron detection device and a DC bias power supply. When secondary electrons or field-emission electrons approach the insulating ceramic, due to the effect of the DC bias, the secondary electrons on the ceramic surface are led out through the metal probe, thereby reducing the probability of sparking caused by secondary electron emission, and the secondary electron current is measured through the secondary electron detection device, which provides a basis for evaluating the electrical vacuum condition in the X-ray tube, thereby enabling users to monitor the X-ray tube in real time.

[0021] The beneficial effects of the X-ray tube of the present invention are as follows: since it has the insulating ceramic as described above, and in the actual working process, the metal probe is electrically connected to the secondary electron detection device and the DC bias power supply, when secondary electrons or field-emission electrons approach the insulating ceramic, due to the effect of the DC bias, the secondary electrons on the surface of the ceramic are led out through the metal probe, thereby reducing the probability of sparking caused by the secondary electron emission, and the secondary electron detection device is used to measure the current of the secondary electrons, which provides a basis for evaluating the electrical vacuum condition in the X-ray tube, thereby realizing real-time monitoring of the X-ray tube by the user.

[0022] The beneficial effects of the secondary electron testing method of the present invention are as follows: in the actual working process, the metal probe is electrically connected to the secondary electron detection device and the DC bias power supply. The negative potential formed by the DC bias power supply on the end of the metal probe can realize the collection of secondary electrons in the X-ray tube and display them on the secondary electron detection device, thereby realizing real-time monitoring of the number of secondary electrons generated in the X-ray tube during the operation of the X-ray tube and promptly prompting the user when sparking occurs.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a first insulating ceramic according to an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of the internal structure of the insulating ceramic shown;

[0026] Figure 3 is a schematic structural diagram of a second insulating ceramic according to an embodiment of the present invention;

[0027] Figure 4 is a schematic structural diagram of a third insulating ceramic according to an embodiment of the present invention;

[0028] Figure 5 is a schematic structural diagram of a fourth insulating ceramic according to an embodiment of the present invention;

[0029] Figure 6 is a schematic structural diagram of a fifth insulating ceramic according to an embodiment of the present invention;

[0030] Figure 7 is a schematic structural diagram of an X-ray tube according to an embodiment of the present invention;

[0031] Reference numerals:

[0032] 100, insulating ceramic; 110, ceramic body; 111, first sealing ring; 112, connecting sleeve; 1121, cone surface; 1122, inner hole; 113, second sealing ring; 120, metal probe; 130, outer connecting tube; 140, inner connecting tube; 141, connecting edge; 150, creepage structure;

[0033] 200, tube shell; 300, cathode assembly; 400, anode assembly; 500, support assembly; 600, X-ray window. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0038] The present invention discloses an insulating ceramic 100, referring to Figure 7 As shown, the insulating ceramic 100 is installed on the X-ray tube, which includes a tube shell 200, a cathode assembly 300, an anode assembly 400 and a support assembly 500. The anode assembly 400 is rotatably arranged in the support assembly 500, and the cathode assembly 300 and the support assembly 500 are respectively located at two ends of the tube shell 200.

[0039] refer to Figure 1 and Figure 2As shown, the insulating ceramic 100 disclosed in the present invention includes a ceramic body 110 and a metal probe 120, the outer peripheral wall of the ceramic body 110 includes a conical surface 1121, and the small end of the conical surface 1121 is sealed and connected to the support assembly 500 of the anode assembly 400, the large end of the ceramic body 110 is sealed and connected to the tube shell 200, there are multiple metal probes 120, and the multiple metal probes 120 are arranged at circumferential intervals around the ceramic body 110, each metal probe 120 is penetrated by the conical surface 1121, and each metal probe 120 is used to be connected to an external secondary electron detection device, and the other end of the metal probe 120 is used to collect secondary electrons in the tube shell 200. It can be understood that since the metal probe 120 is provided on the insulating ceramic 100, during the actual working process, the metal probe 120 is electrically connected to the secondary electron detection device and the DC bias power supply. When secondary electrons or field emission electrons approach the insulating ceramic 100, due to the effect of the DC bias, the secondary electrons on the ceramic surface are led out through the metal probe 120, thereby reducing the probability of sparking caused by the secondary electron emission. In addition, the current of the secondary electrons is measured through the secondary electron detection device, which provides a basis for evaluating the electrical vacuum condition in the X-ray tube, thereby realizing real-time monitoring of the X-ray tube by the user.

[0040] Optionally, there are four metal probes 120 , and the four metal probes 120 are evenly spaced apart and arranged on the tube shell 200 .

[0041] Optionally, the material of the ceramic body 110 is aluminum oxide, aluminum nitride, or silicon nitride. Of course, the ceramic body 110 can also be made of other materials according to actual needs, and is not limited to the above limitations.

[0042] In some embodiments, at least one of the inner wall, the outer wall, and the end surface away from the tube shell 200 of the insulating ceramic 100 is provided with a creepage structure 150, and the creepage structure 150 is used to increase the creepage distance of the insulating ceramic 100. It can be understood that the creepage structure 150 can increase the creepage distance of the insulating ceramic 100, thereby improving the voltage resistance performance of the insulating ceramic 100.

[0043] In some specific embodiments, Figure 4-Figure 6 As shown, the creepage structure 150 includes a plurality of convex rings, which are arranged at intervals on the inner side wall of the insulating ceramic 100. The cross-section of the convex ring can be selected according to actual needs, and can be semicircular, square, or polygonal. The convex ring can be a circular ring or a wavy ring. The structure of the convex ring can be selected according to actual needs.

[0044] In an alternative embodiment, the creepage structure 150 includes a plurality of grooves, and the plurality of grooves are arranged at intervals.

[0045] In another alternative embodiment, the inner wall, the outer wall and the end surface of the insulating ceramic 100 away from the tube shell 200 are all inclined surfaces, thereby increasing the creepage distance of the insulating ceramic 100 to a certain extent.

[0046] It should be supplemented that, in some embodiments, the creepage structure 150 is only provided on the inner wall of the insulating ceramic 100; in some embodiments, the creepage structure 150 is only provided on the outer wall of the insulating ceramic 100; in some embodiments, the creepage structure 150 is only provided on the end face away from the tube shell 200; in some embodiments, the creepage structure 150 is provided on the inner wall and the outer wall of the insulating ceramic 100; in some embodiments, the creepage structure 150 is provided on the inner wall of the insulating ceramic 100 and the end face away from the tube shell 200; in some embodiments, the creepage structure 150 is provided on the outer wall of the insulating ceramic 100 and the end face away from the tube shell 200; in some embodiments, the creepage structure 150 is provided on the inner wall, the outer wall and the end face away from the tube shell 200 of the insulating ceramic 100. The specific distribution of the creepage structure 150 can be selected according to actual needs.

[0047] In some embodiments, the ceramic body 110 includes a first sealing ring 111, a connecting sleeve 112 and a second sealing ring 113 connected in sequence, the outer peripheral wall of the connecting sleeve 112 is a conical surface 1121, and the first sealing ring 111 is sealed and connected to the support assembly 500, and the second sealing ring 113 is sealed and connected to the tube shell 200.

[0048] In some specific embodiments, the outer diameter of the first sealing ring 111 is 40 mm-70 mm, and the outer diameter of the first sealing ring 111 can be 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm. The outer diameter of the first sealing ring 111 can also be other values ​​within the range of 40 mm-70 mm, and the outer diameter of the first sealing ring 111 can also be selected from other sizes according to actual needs, and is not limited to the above limitations.

[0049] In some specific embodiments, the outer diameter of the second sealing ring 113 is 80 mm-120 mm. The outer diameter of the second sealing ring 113 can be 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm. The outer diameter of the second sealing ring 113 can also be other values ​​within the range of 80 mm-120 mm. The outer diameter of the second sealing ring 113 can also be selected from other sizes according to actual needs, and is not limited to the above limitations.

[0050] In some specific embodiments, the total height of the connecting sleeve 112 is 20 mm-60 mm. The total height of the connecting sleeve 112 can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm. The total height of the connecting sleeve 112 can also be other values ​​within the range of 20 mm-60 mm. The total height of the connecting sleeve 112 can also be selected from other sizes according to actual needs, and is not limited to the above limitations.

[0051] In some specific embodiments, the height of the second sealing ring 113 is 15 mm-30 mm. The height of the second sealing ring 113 can be 15 mm, 20 mm, 25 mm, 30 mm, or other values ​​within the range of 15 mm-30 mm. The height of the second sealing ring 113 can also be other sizes according to actual needs, and is not limited to the above limitations.

[0052] In some specific embodiments, the inner hole 1122 of the connecting sleeve 112 is a straight hole, and the diameter of the inner hole 1122 is 20 mm-60 mm. The diameter of the inner hole 1122 can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm. The diameter of the inner hole 1122 can also be other values ​​within the range of 20 mm-60 mm, and the diameter of the inner hole 1122 can also be selected from other sizes according to actual needs, and is not limited to the above limitations.

[0053] In some specific embodiments, Figure 3 As shown, the insulating ceramic 100 further includes an external connection tube 130, one end of which is sealedly connected to the second sealing ring 113, the other end of which is sealedly connected to the tube shell 200, and the inner side wall of the external connection tube 130 is spaced apart from the anode assembly 400. It can be understood that, by using the external connection tube 130 as an intermediate piece for sealing the connection sleeve 112 and the tube shell 200, the insulating ceramic 100 can be conveniently sealedly connected to the metal tube shell 200, which simplifies the connection and improves the connection sealing.

[0054] Optionally, the external connection tube 130 is made of a calenderable material and is connected to the tube shell 200 and the second sealing ring 113 by brazing, argon arc welding, etc. Of course, in other embodiments of the present invention, the material of the external connection tube 130 and the sealing connection method with the tube shell 200 and the second sealing ring 113 can be selected according to actual needs and are not limited to the above limitations.

[0055] In some specific embodiments, Figure 3As shown, the insulating ceramic 100 further includes an inner connecting tube 140, one end of which is sealedly connected to the first sealing ring 111, and the other end is sealedly connected to the support assembly 500. The inner connecting tube 140 is used as an intermediate piece for sealing the connecting sleeve 112 and the support assembly 500, so that the insulating ceramic 100 can be conveniently connected to the metal support assembly 500, which simplifies the connection and improves the connection sealing.

[0056] In some more specific embodiments, the inner connecting tube 140 has a connection sealing edge 141 that fits the outer peripheral wall of the first sealing ring 111. Therefore, the inner connecting tube 140 is provided with a connection sealing edge 141 to better achieve the connection between the inner connecting tube 140 and the insulating material, thereby ensuring the connection stability and connection sealing of the two.

[0057] Optionally, the inner connecting tube 140 is made of a ductile material and is connected to the support assembly 500 and the first sealing ring 111 by brazing, argon arc welding, etc. Of course, in other embodiments of the present invention, the material of the inner connecting tube 140 and the sealing connection method with the support assembly 500 and the first sealing ring 111 can be selected according to actual needs and are not limited to the above limitations.

[0058] In some embodiments, the metal probe 120 is supported by a material with high conductivity and high melting point, such as nickel or tungsten. Its diameter is 2 mm to 4 mm, and its tip is rounded, with a diameter of 2 mm to 3 mm. This ensures that the metal probe 120 is stably welded to the insulating ceramic 100 and that the metal probe 120 can extract secondary electrons.

[0059] Optionally, the metal probe 120 and the insulating ceramic 100 are welded by brazing using pure copper solder in a vacuum furnace.

[0060] The present invention also discloses an X-ray tube, such as Figure 7As shown, the X-ray tube includes a tube shell 200, a cathode assembly 300, an anode assembly 400 and the insulating ceramic 100 mentioned above. The tube shell 200 usually includes a plurality of metal shells and is connected by welding to realize that the inside of the tube shell 200 can define a vacuum environment. Stainless steel material is usually used as the tube shell 200. The cathode assembly 300 is arranged at one end of the tube shell 200. The cathode assembly 300 mainly includes structures such as a cathode insulating ceramic part, an electron gun component and a cathode sealing edge. Among them, the electron gun components include but are not limited to a grid electron gun, a focusing pole double filament electron gun structure, etc., which can be selected according to actual needs. The anode assembly 400 includes a target disk and an anode shaft handle. The target disk is mainly composed of a molybdenum-titanium-zirconium alloy. The diameter of the target disk is 140mm-210mm. The anode shaft handle is used to realize the rotatable cooperation between the target disk and the support assembly 500. The support assembly 500 includes a bearing structure and a rotating fixed seat. The bearing structure is sleeved on the anode shaft handle and the rotating fixed seat is installed. The bearing structure can adopt a liquid metal bearing or a ball bearing. The anode assembly 400 and the cathode assembly 300 are respectively located at the two ends of the tube shell 200. The middle of the tube shell 200 is also provided with an X-ray window 600 for emitting X-rays. To increase the X-ray transmittance and ensure the vacuum strength, the window material is usually beryllium or titanium. The outer connecting tube 130 of the insulating ceramic 100 is connected to the tube shell 200, and the inner connecting tube 140 is connected to the rotating fixed seat.

[0061] It is understandable that in the actual working process, a wire with a metal inner conductor is used, one end of which is fixed on the tube shell 200 and the other end is connected to the ground potential, so that the outer wall of the tube shell 200 and the rotating fixed seat are all at zero potential. And one end of the metal probe 120 of the insulating ceramic 100 is connected to the secondary electron detection device, and the secondary electron detection device is connected to the DC bias power supply. The DC bias power supply is a negative voltage generating device that can generate a voltage in the range of -20V to -5V. The secondary electron monitoring device is characterized by an oscilloscope device. Since the generation and release of secondary electrons is a pulse process, the rising and falling edges of the pulse current signal are captured by triggering the oscilloscope, and then the information of the secondary electron current and duration is obtained. Since the metal probe 120 is provided on the insulating ceramic 100, the negative potential generated by the DC bias power supply can realize the collection of secondary electrons in the X-ray tube, reduce the probability of sparking caused by secondary electron emission, and measure the current size of the secondary electrons through the secondary electron current device, which provides a basis for evaluating the electric vacuum condition in the X-ray tube.

[0062] The present invention also discloses a secondary electron testing method, which is used to detect whether secondary electrons exist inside the tube shell 200 of the aforementioned X-ray tube; during the testing process, the tube shell 200 is grounded, one end of the metal probe 120 of the insulating ceramic 100 is connected to a secondary electron detection device, and the secondary electron detection device is connected to a DC bias power supply; wherein: if the current value detected by the secondary electron detection device is not zero, secondary electrons exist inside the tube shell 200 of the X-ray tube; if the current detected by the secondary electron detection device is greater than a preset value, sparking occurs inside the tube shell 200 of the X-ray tube.

[0063] It can be understood that, in actual operation, the metal probe 120 is electrically connected to the secondary electron detection device and the DC bias power supply. The negative potential formed by the DC bias power supply at the end of the metal probe 120 can collect the secondary electrons in the X-ray tube and display them on the secondary electron detection device, thereby realizing real-time monitoring of the number of secondary electrons generated in the X-ray tube during operation of the X-ray tube and promptly prompting the user when sparking occurs.

[0064] It should be additionally explained that the method of prompting the user here can be an acoustic and optical signal prompt emitted by a buzzer or flash lamp connected to the secondary electron detection device, or the secondary electron detection device itself can have a prompt function. It should be additionally explained here that in the embodiment of the present invention, the preset value can be arbitrarily set according to the working parameters of the X-ray, and the specific value of the preset value is not limited here.

[0065] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An insulating ceramic, the insulating ceramic is installed in an X-ray tube, the X-ray tube comprises a tube shell, a support assembly, a cathode assembly and an anode assembly, the anode assembly is rotatably arranged in the support assembly, the cathode assembly and the support assembly are respectively installed at two ends of the tube shell, characterized in that: The insulating ceramic comprises: A ceramic body, wherein the outer peripheral wall of the ceramic body comprises a conical surface, and the small end of the conical surface is sealed and connected to the support assembly, and the large end of the ceramic body is sealed and connected to the tube shell; There are multiple metal probes, and the multiple metal probes are arranged at intervals around the circumference of the ceramic body. Each metal probe passes through the conical surface, and each metal probe is used to be connected to an external secondary electron detection device. The other end of the metal probe is used to collect secondary electrons in the tube shell.

2. The insulating ceramic according to claim 1, characterized in that: A creepage structure is provided on at least one of the inner side wall, the outer side wall and the end surface away from the tube shell of the insulating ceramic, and the creepage structure is used to increase the creepage distance of the insulating ceramic.

3. The insulating ceramic according to claim 2, characterized in that: The creepage structure includes a plurality of convex rings, which are arranged at intervals on at least one of the inner side wall, the outer side wall and the end face away from the tube shell of the insulating ceramic, or, The creepage structure comprises a plurality of grooves, and the plurality of grooves are arranged at intervals on at least one of the inner side wall, the outer side wall and the end surface away from the tube shell of the insulating ceramic.

4. The insulating ceramic according to claim 1, characterized in that The ceramic body comprises a first sealing ring, a connecting sleeve and a second sealing ring which are connected in sequence, the outer peripheral wall of the connecting sleeve is the conical surface, the first sealing ring is sealedly connected to the supporting assembly, and the second sealing ring is sealedly connected to the tube shell.

5. The insulating ceramic according to claim 4, characterized in that: The inner hole of the connecting sleeve is a straight hole, the outer diameter of the first sealing ring is 40mm-70mm, the outer diameter of the second sealing ring is 80mm-120mm, the total height of the connecting sleeve is 20mm-60mm, the height of the second sealing ring is 15mm-30mm, and the diameter of the inner hole is 20mm-60mm.

6. The insulating ceramic according to claim 4, characterized in that: The insulating ceramic further comprises an external connection tube, one end of which is sealedly connected to the second sealing ring, the other end of which is sealedly connected to the tube shell, and the inner side wall of the external connection tube is spaced apart from the anode assembly.

7. The insulating ceramic according to claim 4, characterized in that: The insulating ceramic further comprises an inner connecting tube, one end of which is sealingly connected to the first sealing ring, and the other end of which is sealingly connected to the supporting assembly.

8. The insulating ceramic according to claim 7, characterized in that: The inner connecting tube has a connecting sealing edge which is in contact with the outer peripheral wall of the first sealing ring.

9. An X-ray tube, characterized in that: It comprises a tube shell, a cathode assembly, an anode assembly and an insulating ceramic as described in any one of claims 1 to 8, wherein a support assembly is provided in the tube shell, the anode assembly is rotatably mounted on the support assembly, the anode assembly and the cathode assembly are respectively located at two ends of the tube shell, and the insulating ceramic is sealed and connected to the tube shell and the support assembly.

10. A secondary electron testing method, characterized in that: The secondary electron testing method is used to detect whether there are secondary electrons inside the tube shell of the X-ray tube as claimed in claim 9; During the test, the tube shell is grounded, one end of the metal probe of the insulating ceramic is connected to a secondary electron detection device, and the secondary electron detection device is connected to a DC bias power supply; wherein: If the current value detected by the secondary electron detection device is not zero, secondary electrons exist inside the tube shell of the X-ray tube; If the current detected by the secondary electron detection device is greater than a preset value, sparks may occur inside the tube shell of the X-ray tube.

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