Pressure-resistant X-ray tube

Abstract

The utility model discloses a voltage-withstanding X-ray tube, which belongs to the technical field of X-ray tubes, and specifically comprises a shell, an anode assembly and a cathode assembly are fixed in the shell, a voltage-withstanding part is fixed on each of the anode assembly and the cathode assembly, and the voltage-withstanding parts are simultaneously fixed with the shell. A vacuum space is formed among the two pressure-resistant pieces, the shell, the anode assembly and the cathode assembly, and the faces, facing each other, of the pressure-resistant pieces are in a corrugated shape. According to the utility model, the corrugated voltage-withstanding parts are respectively fixed on the cathode assembly and the anode assembly, so that the distance of creepage arc length is increased compared with a flat plate type voltage-withstanding part, and the voltage-withstanding performance of the voltage-withstanding part is effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to X ray tube technical field, especially relate to a pressure -proof X ray tube. BACKGROUND

[0002] The hot cathode X ray tube is mainly composed of an anode assembly, a cathode assembly and a sealed tube shell. The hot cathode assembly is mainly an electron source, which is generally a spiral filament made of tungsten wire. A certain filament current is applied to heat the cathode to a high temperature state, so that an electron beam can be generated. After being accelerated by the high-voltage electric field between the cathode assembly and the anode target, the electron beam bombards the anode target, thereby generating X rays.

[0003] The higher the voltage that can be withstood between the cathode and the anode, the higher the energy generated by the X rays, and the stronger the ability of the X rays to penetrate objects. The way to achieve this potential difference is to use a pressure -proof piece. The ceramic shape determines the maximum voltage that can be withstood between the cathode / anode and the shell.

[0004] The pressure -proof piece currently mainly used in the market is a flat plate structure, and most of the published patents and general applications are concentrated in 160KV high voltage, which to some extent limits the development process of high-voltage electric vacuum products. Based on the above problems, the present application realizes the use of the X ray tube at a higher voltage by designing the structure of the X ray tube. SUMMARY

[0005] The utility model discloses a pressure -proof X ray tube to solve the problem raised in the background art.

[0006] To achieve the above object, the utility model adopts one technical scheme: a pressure -proof X ray tube, including the shell, the shell is fixed with anode assembly and cathode assembly, the anode assembly and cathode assembly all are fixed with a pressure -proof piece, the pressure -proof piece is fixed with the shell simultaneously, make two pressure -proof pieces, the shell, anode assembly and cathode assembly form vacuum space between, the face of the pressure -proof piece each other is corrugated.

[0007] Preferably, the cross section of the pressure -proof piece is formed by a straight bottom edge, two straight side edges arranged vertically to the straight bottom edge, an inclined edge arranged inwardly and upwardly connecting the two straight side edges, and a transition arc connecting the two inclined edges, and is formed along a circular route.

[0008] Preferably, the surface formed by the two straight side edges of the pressure -proof piece is coated with a metal layer.

[0009] Preferably, a chamfer / groove for suppressing local electric field enhancement is formed at the connection between the two inclined edges and the two straight side edges.

[0010] Preferably, the two pressure-resistant parts in the X-ray tube are coated with a voltage-resistant coating on the surfaces facing each other.

[0011] The utility model discloses the beneficial effect: this scheme is fixed a corrugated pressure-resistant part on cathode assembly and anode assembly respectively, and the distance of creeping arc length is increased relative to flat plate type pressure-resistant part, and the pressure resistance of pressure-resistant part is effectively promoted.

[0012] Among them, the shape design of the pressure-resistant part of the scheme can increase the creeping arc length as far as possible, and can effectively avoid the generation of sharp tip discharge phenomenon;

[0013] Among them, the circular ring type design can ensure the uniformity of the electric field on the pressure-resistant part, and ensures the stability during the use of the product.

[0014] Among them, the metal layer on the pressure-resistant part is used for conveniently welding and fixing the pressure-resistant part with the cathode assembly, the anode assembly and the shell.

[0015] Among them, the voltage-resistant coating can further enhance the voltage resistance of the product. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structural diagram of the utility model;

[0017] Figure 2 It is the axial section schematic view of the pressure-resistant part of the utility model;

[0018] Figure 3 It is the simulation result diagram of the surface electrostatic field of the traditional flat plate type pressure-resistant part;

[0019] Figure 4 It is the simulation result diagram of the surface electrostatic field of the pressure-resistant part in the utility model;

[0020] In the drawing: 1, shell; 2, anode assembly; 3, cathode assembly; 4, pressure-resistant part; 41, flat bottom edge;

[0021] 42, flat side edge one; 43, flat side edge two; 44, bevel edge one; 45, bevel edge two; 46, transition arc; 5, chamfer / groove. DETAILED DESCRIPTION

[0022] The preferred embodiments of the utility model will be described in detail below with reference to the drawings, so that the advantages and features of the utility model can be more easily understood by the person skilled in the art, and the protection scope of the utility model can be more clearly and explicitly defined.

[0023] Embodiment:

[0024] Reference Figure 1A pressure-resistant X-ray tube is disclosed, comprising a housing 1, an anode assembly 2 and a cathode assembly 3 fixed inside the housing 1, and a pressure-resistant component 4 fixed on each of the anode assembly 2 and the cathode assembly 3. The pressure-resistant component 4 is also fixed to the housing 1, thereby forming a vacuum space between the two pressure-resistant components 4, the housing 1, the anode assembly 2 and the cathode assembly 3. The surfaces of the pressure-resistant components 4 facing each other are corrugated. In this embodiment, the pressure-resistant component 4 is made of alumina ceramic, which has high voltage resistance.

[0025] Among them, see Figure 2 The pressure-resistant component 4 is formed by scanning along a circular path through a cross section consisting of a straight bottom edge 41, a straight side edge 42 perpendicular to the left end of the straight bottom edge and upward, a straight side edge 43 perpendicular to the right end of the straight bottom edge and upward, a first inclined side edge 44 connected to the upper end of the first straight side edge 42 and inclined side edge 45 connected to the upper end of the second straight side edge 43 and inclined side edge 45 and upward convex transition arc 46 connecting the upper ends of the first inclined side edge 44 and the second inclined side edge 45. The first inclined side edge, the second inclined side edge and the transition arc form an irregular corrugated shape.

[0026] The pressure-resistant component 4 has a metal layer coated on the surface formed by scanning the first straight side 42 and the second straight side 43. The metal layer on the first straight side 42 is used to facilitate welding and fixing to the inner wall of the outer shell, and the metal layer on the second straight side 43 is used to facilitate welding and fixing to the side wall of the cathode assembly or the side wall of the anode assembly.

[0027] Wherein, chamfers / grooves 5 are provided at the connection points between the two inclined sides and the two straight sides to suppress the enhancement of local electric field.

[0028] The two pressure-resistant components 4 inside the X-ray tube are coated with a voltage-resistant coating on their mutually facing surfaces, such as chromium oxide.

[0029] The X-ray tube structure of this design can significantly reduce the electric field intensity on the ceramic surface and improve pressure resistance. Specifically, taking an X-ray tube with an inner diameter of φ100-150mm and a diameter of φ40-60mm at the assembly point of the anode and cathode outer walls as an example, a pressure-resistant component 4 with a maximum height of 20-30mm and a creepage arc length (i.e., the total length of the hypotenuse and the transition arc connecting the two hypotenuses) of 55-65mm is selected. (See reference...) Figure 3 Electrostatic field simulation diagram ( Figure 3 The figures (from top to bottom) show the results of a traditional flat-plate cathode ceramic pressure-resistant component and an anode ceramic pressure-resistant component. In a double-ended X-ray tube with cathode component 3 at a negative voltage of -225kV and anode component 2 at a positive voltage of 225kV, forming a total voltage environment of 450kV, the maximum electric field on the surface of the flat-plate pressure-resistant component 4 is 41MV / m; see reference. Figure 4Electrostatic field simulation diagram ( Figure 4 The figures, from top to bottom, show the results of the cathode ceramic pressure-resistant component and the anode ceramic pressure-resistant component in this scheme. In a 450kV high-energy double-ended X-ray tube with a -225kV negative high voltage on the inner wall of the cathode ceramic and a 225kV positive high voltage on the inner wall of the anode ceramic, the maximum electric field of the pressure-resistant ceramic component in this scheme is 35MV / m. It can be seen that compared with the X-ray tube of the traditional flat plate pressure-resistant component 4, the maximum electric field on the surface of the pressure-resistant component 4 in this scheme is reduced by about 15%. This means that compared with the traditional flat plate pressure-resistant component 4, the structure of this scheme can be used in a stronger electric field environment.

[0030] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A voltage withstanding type X-ray tube, characterized by: The application relates to an X-ray tube, which comprises a shell (1), an anode assembly (2) and a cathode assembly (3) fixed in the shell (1), a voltage-resistant part (4) fixed on the anode assembly (2) and the cathode assembly (3), and two voltage-resistant parts (4) fixed on the shell (1) at the same time, so that a vacuum space is formed among the two voltage-resistant parts (4), the shell (1), the anode assembly (2) and the cathode assembly (3), and the surfaces of the two voltage-resistant parts (4) facing each other are corrugated.

2. A voltage standing wave type X-ray tube according to claim 1, characterized in that: The cross section of the voltage-resistant part (4) is formed by a straight bottom edge (41), a straight side edge one (42) arranged upwardly and perpendicularly to the left end of the straight bottom edge, a straight side edge two (43) arranged upwardly and perpendicularly to the right end of the straight bottom edge, an oblique edge one (44) arranged obliquely upwardly and connected to the upper end of the straight side edge one (42), an oblique edge two (45) arranged obliquely upwardly and connected to the upper end of the straight side edge two (43), and a transition arc (46) arranged upwardly and connected to the upper ends of the oblique edge one (44) and the oblique edge two (45).

3. A voltage standing wave type X-ray tube according to claim 2, characterized in that: The surfaces of the straight side edge one (42) and the straight side edge two (43) of the voltage-resistant part (4) are coated with a metal layer.

4. A voltage standing wave type X-ray tube according to claim 2, characterized in that: Chamfers / grooves (5) for inhibiting local electric field enhancement are arranged at the connection positions of the two oblique edges and the two straight side edges.

5. A voltage standing wave type X-ray tube according to claim 1, characterized in that: The surfaces of the two voltage-resistant parts (4) facing each other are coated with a voltage-resistant coating.

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