X-ray tube and method for manufacturing same

Abstract

An X-ray tube according to an embodiment may include: a tube-type vacuum container having a first axis; a cathode disposed at the lower end of the tube-type vacuum container and including an electron source from which electrons are emitted; an anode disposed at the upper end of the tube-type vacuum container and including a front end portion to which the electrons emitted from the electron source are irradiated to emit X-rays; an insulating cover including a first insulating portion sharing the first axis with the tube-type vacuum container and a second insulating portion filled between the outer circumferential surface of the tube-type vacuum container and the inner circumferential surface of the first insulating portion; and an irradiation port through which the X-rays emitted from the front end portion are emitted to the outside.

Description

X-ray tube and method of manufacturing the same

[0001] The present disclosure relates to an X-ray tube and a method for manufacturing the same.

[0002] This disclosure is derived from research conducted as part of the 'BRIDGE Convergence Research and Development Project' with funding from the government (Ministry of Science and ICT) and support from the National Research Foundation of Korea.

[0003] [Project ID: RS-2023-00240135, Research Title: Development of a Patient-Specific Carbon Nano X-ray Tube-Based Multi-Source C-arm CT Imaging System Equipped with 3D Position Tracking Navigation for Robotic Surgery Image Guidance]

[0004] X-rays are electromagnetic waves with good penetrating power through objects and can be used for non-destructive and non-contact observation of the internal structures of objects or the human body. Electrons emitted from the cathode electrode are accelerated by the anode electrode and collide with the anode electrode tungsten target, and only a portion (less than about 1%) of the electrical energy applied to the X-ray tube is emitted as X-rays from the anode electrode target. The X-rays emitted from the anode electrode are extracted to the outside of the X-ray tube and can be used for non-destructive and non-contact observation of the internal structures of objects or the human body.

[0005] The present disclosure provides technology regarding an X-ray tube and a method for manufacturing the same.

[0006] One aspect of the present disclosure provides embodiments of an X-ray tube. An X-ray tube according to one embodiment may include a tubular vacuum vessel having a first axis, a cathode disposed at the bottom of the tubular vacuum vessel and comprising an electron source from which electrons are emitted, an anode disposed at the top of the tubular vacuum vessel and comprising a tip portion into which electrons emitted from the electron source are irradiated to emit X-rays, an insulating cover comprising a first insulating portion sharing the first axis with the tubular vacuum vessel and a second insulating portion filled between the outer surface of the tubular vacuum vessel and the inner surface of the first insulating portion, and an irradiation port for extracting the X-rays emitted from the tip portion to the outside.

[0007] In one embodiment, the second insulating portion may be formed to protrude in a direction spaced apart from the first axis around the irradiation area.

[0008] In one embodiment, the first insulating part may include a non-elastic material, and the second insulating part may include an elastic material.

[0009] In one embodiment, the first insulating part may be made of acrylic or polycarbonate, and the second insulating part may be made of epoxy or silicone.

[0010] In one embodiment, a conductive cylinder surrounding at least a portion of the outer surface of the first insulating part may be further included.

[0011] In one embodiment, the conductive cylinder may be formed to extend upward from the bottom of the first insulating part.

[0012] In one embodiment, the anode may further include an anode cap covering at least a portion of the tip portion.

[0013] In one embodiment, the tubular vacuum container may be made of a ceramic material.

[0014] One aspect of the present disclosure provides embodiments of a method for manufacturing an X-ray tube. A method for manufacturing an X-ray tube having a multilayer insulating structure according to one embodiment may include the steps of: manufacturing an X-ray generating unit comprising a tubular vacuum vessel having a first axis, a cathode disposed at the bottom of the tubular vacuum vessel and comprising an electron source from which electrons are emitted, and an anode disposed at the top of the tubular vacuum vessel and comprising a tip portion that emits X-rays when irradiated with electrons emitted from the electron source; arranging a first insulating portion such that the first insulating portion, having an inner diameter larger than the outer diameter of the tubular vacuum vessel, shares a first axis with the tubular vacuum vessel; filling a fluid insulating liquid between the tubular vacuum vessel and the first insulating portion; and curing the insulating liquid to form a second insulating portion.

[0015] In one embodiment, the first insulating part includes a first hole, and after the step of arranging the first insulating part, the method further includes the step of inserting a cylindrical mold into the first hole, and after the step of forming the second insulating part, the method further includes the step of removing the cylindrical mold.

[0016] According to one embodiment of the present disclosure, high-power X-rays can be stably irradiated from an X-ray tube.

[0017] According to one embodiment of the present disclosure, the amount of X-ray exposure to an object or a part of the human body can be easily controlled.

[0018] According to one embodiment of the present disclosure, a more accurate diagnostic image can be provided.

[0019] The effects according to the technology of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description of the present disclosure.

[0020] FIG. 1 is a perspective view of an X-ray tube according to one embodiment of the present disclosure.

[0021] Figure 2 is a cross-sectional view of an X-ray tube cut along a plane that shares a through hole with the A1 axis of Figure 1.

[0022] FIG. 3 is a diagram illustrating the movement of scattered electrons with and without an anode electrode cap according to one embodiment of the present disclosure.

[0023] FIG. 4 is a cross-sectional view of an X-ray tube according to an embodiment in which a conductive cylinder is added to the embodiments of FIG. 1 and FIG. 2.

[0024] FIG. 5 is a flowchart of a method for manufacturing an X-ray tube according to one embodiment of the present disclosure.

[0025] The embodiments of the present disclosure are illustrative for the purpose of explaining the technical concept of the present disclosure. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the specific description thereof.

[0026] All technical and scientific terms used in this disclosure, unless otherwise defined, have the meaning generally understood by those skilled in the art to which this disclosure pertains. All terms used in this disclosure are selected for the purpose of further clarifying this disclosure and are not selected to limit the scope of the rights under this disclosure.

[0027] Expressions such as “comprising,” “comprising,” “having,” etc. used in this disclosure should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence containing such expressions.

[0028] Unless otherwise stated, singular expressions described in this disclosure may include a plural meaning, and this applies likewise to singular expressions described in the claims.

[0029] Expressions such as "first," "second," etc. used in this disclosure are used to distinguish multiple components from one another and do not limit the order or importance of said components.

[0030] In the present disclosure, where it is stated that a component is "connected" or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, or connected or connected through a new component.

[0031] The dimensions and numbers described in this disclosure are not limited to the stated dimensions and numbers alone. Unless otherwise specified, such dimensions and numbers may be understood to mean the stated values ​​and equivalent ranges including them. For example, the dimension '50 mm' described in this disclosure may be understood to include 'about 50 mm'.

[0032] Embodiments of the present disclosure will be described below with reference to the attached drawings. In the attached drawings, identical or corresponding components are given the same reference numerals. Furthermore, in the description of the embodiments below, the description of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such component is not included in any embodiment.

[0033] FIG. 1 is a perspective view of an X-ray tube (100) according to one embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the X-ray tube (100) cut along A-A' of FIG. 1. Referring to FIG. 1 and FIG. 2, the X-ray tube (100) may include a tubular vacuum vessel (110), a cathode electrode (120), a gate electrode (125), an anode electrode (130), an insulating cover (140), and an irradiation port (150).

[0034] In one embodiment, the tubular vacuum vessel (110) may be made of an insulating material such as ceramic, glass, or silicon. As the tubular vacuum vessel (110) is made of an insulating material, the cathode electrode (120) and the anode electrode (130) can be electrically insulated from each other. According to one embodiment of the present invention, the cathode electrode (120) is not in direct contact with the tubular vacuum vessel (110) but is positioned at the inner center along the first axis (A1) of the tubular vacuum vessel (110), and the anode electrode (130) is also positioned at the inner center along the first axis (A1). Accordingly, the dielectric strength between the cathode electrode (120) and the anode electrode (130) can be maximized. This is because when an insulating material with constant electrical conductivity is interposed between two conductors, the dielectric strength increases as the insulating distance made of the insulating material increases. The tubular vacuum vessel (110) has a bottom and a top through which it penetrates along the first axis (A1). A cathode electrode (120) and an anode electrode (130) may be disposed at the bottom and top of the tubular vacuum vessel (110), respectively. The interior of the tubular vacuum vessel (110) is sealed by the cathode electrode (120) and the anode electrode (130), so that the internal space (111) can be vacuumed.

[0035] In one embodiment, the cathode electrode (120) may be positioned at the bottom of the tubular vacuum vessel (110). The cathode electrode (120) may be made of a negative electrode. The cathode electrode (120) may include an electron source (121) that emits electrons. The electron source (121) may generate electrons and emit them toward the anode electrode (130). The electrons generated from the electron source (121) may be emitted in a direction parallel to the first axis (A1). A gate electrode (125) may be positioned between the electron source (121) and the anode electrode (130). The gate electrode (125) may be positioned close to the electron source (121) to form an electric field that initiates electron emission.

[0036] In one embodiment, the anode electrode (130) may be positioned at the top of the tubular vacuum vessel (110). In one embodiment, the anode electrode (130) may be made of a positive electrode. The anode electrode (130) may be surrounded by a conductive material. The anode electrode (130) may emit X-rays in a direction (Dx) perpendicular to the direction of electron emission (De) emitted from the cathode electrode (120). The anode electrode (130) may include a base portion (131) and a tip portion (132). The base portion (131) may extend from the top of the tubular vacuum vessel (110) toward the cathode electrode (120). A high voltage may be applied to the base portion (131). The tip portion (132) may correspond to the end portion of the anode electrode (130) on the side of the cathode electrode (120) of the base portion (131). Electrons incident on the anode electrode (130) collide with the tip portion (132) at high speed, and the kinetic energy of the electrons can be converted into X-rays and thermal energy. X-rays can be emitted from the tip portion (132) through such energy conversion. X-rays generated from the tip portion (132) can pass through the irradiation hole (150) and be irradiated to the outside. Referring to FIG. 2, the direction of electron emission (De) and the direction of X-ray movement (Dx) may be perpendicular to each other. In order for the direction of electron emission (De) and the direction of X-ray movement (Dx) to be perpendicular to each other, the tip portion (132) may be positioned at an angle with respect to the direction of electron emission (De). That is, the reflective surface of the tip portion (132) can be positioned to be inclined with respect to the direction of electron emission (De).

[0037] In one embodiment, the anode electrode (130) may further include an anode cap (133). Referring to FIG. 3, electrons (EL) incident on the tip (132) of the anode electrode (130) may be scattered at an angle greater than 90 degrees with respect to the incident direction due to interaction with the radiating material. Electrons scattered in this way are called backscattered electrons (BSE). Backscattered electrons (BSE) may collide with and accumulate on the inner wall of a tubular vacuum vessel (110) made of an insulating material such as ceramic, thereby generating an electric field that interferes with the path of electrons emitted from the electron source (121), and as a result, may degrade the X-ray generation efficiency and the quality of the X-ray spectrum. The anode cap (133) is intended to physically prevent these backscattered electrons (EBS) from accumulating in the tubular vacuum vessel (110), and the anode cap (133) may be formed to cover a portion of the tip (132). The anode cap (133) may extend from the base (131) to the lower side of the tip (132). The anode cap (133) may surround the periphery of the tip (132) but may not surround the direction (De) in which electrons flow into the tip (132) and the direction (Dx) in which X-rays are emitted from the tip (132). That is, the anode cap (133) may include one or more through holes formed in the direction (De) in which electrons flow into the tip (132) and the direction (Dx) in which X-rays are emitted from the tip (132). The anode cap (133) can absorb electrons scattered from the tip (132) of the anode electrode (130) (i.e., backscattered electrons (EBS)). FIG. 3 (a) illustrates the movement of backscattered electrons (EBS) without the anode cap (133), and FIG. 3 (b) illustrates the movement of backscattered electrons (EBS) with the anode cap (133).In FIG. 3(a), the backscattered electrons (EBS) emitted from the leading edge (132) are absorbed directly by the inner wall of the tubular vacuum vessel (110), whereas in FIG. 3(b), at least some of the backscattered electrons (EBS) are absorbed by the anode cap (133) and only the remaining portion is absorbed by the tubular vacuum vessel (110), so it can be seen that the amount of backscattered electrons (EBS) absorbed by the inner wall of the tubular vacuum vessel (110) is significantly reduced when the anode cap (133) is present. Accordingly, the anode cap (133) can improve the X-ray generation efficiency and the quality of the X-ray spectrum.

[0038] In one embodiment, the insulating cover (140) may surround the tubular vacuum container (110) while sharing a first axis (A1) with the tubular vacuum container (110). The insulating cover (140) may include a first insulating portion (141) and a second insulating portion (142). The first insulating portion (141) may be spaced apart from the tubular vacuum container (110) and arranged to surround the outer surface of the tubular vacuum container (110). The first insulating portion (141) shares a first axis (A1) with the tubular vacuum container (110). The first insulating portion (141) may be formed of a rigid, non-elastic material. For example, the first insulating portion (141) may be formed of at least one of acrylic or polycarbonate. In one embodiment, the second insulating portion (142) may be positioned between the tubular vacuum container (110) and the first insulating portion (141). Specifically, the second insulating part (142) can be filled in the space between the outer surface of the tubular vacuum container (110) and the inner surface of the first insulating part (141). The second insulating part (142) can be formed from a soft elastic material. Specifically, the second insulating part (142) can be formed by curing an insulating liquid in a fluid state. For example, the second insulating part (142) can be formed from at least one material of epoxy or silicone. By forming the second insulating part (142) from an elastic material and compressing it between the tubular vacuum container (110) and the first insulating part (141), the insulating cover (140) can be attached to the tubular vacuum container (110) without a gap, thereby increasing the insulation efficiency. The insulating cover (140), which includes the first insulating part (141) and the second insulating part (142), can improve the stability of the X-ray tube (100) by preventing discharge phenomena from occurring even when high-power X-rays are irradiated by forming a multi-layer insulating structure in this way.

[0039] In one embodiment, the irradiation port (150) serves to extract X-rays emitted from the tip (132) of the anode electrode (130) to the outside of the tubular vacuum vessel (110), that is, to the outside of the X-ray tube (100). The irradiation port (150) may be formed parallel to the direction (Dx) in which X-rays are emitted to the outside. The insulating cover (140) may be formed relatively thicker in the surrounding area of ​​the irradiation port (150) compared to other areas. In the surrounding area of ​​the irradiation port (150), the second insulating part (142) of the insulating cover (140) may protrude in a direction spaced apart from the first axis (A1). In the surrounding area of ​​the irradiation port (150), the distance (L2) from the first axis (A1) to the outermost surface of the second insulating part (142) is longer than the distance (L1) from the first axis (A1) to the outermost surface of the first insulating part (141). By forming a second insulating part (142) protruding from the surrounding area of ​​the irradiation area (150), the creeping distance is extended to minimize discharge phenomena and prevent scattering of X-rays, thereby enabling the acquisition of a high-quality image.

[0040] In one embodiment, an X-ray tube (100) comprising the above components is placed inside a box filled with insulating oil and irradiates X-rays toward an object. Here, the insulating oil has the effect of insulating the X-ray tube and cooling the X-ray tube by absorbing and releasing heat generated during X-ray generation.

[0041] FIG. 4 is a cross-sectional view of an X-ray tube (100) according to an embodiment in which a conductive cylinder (160) is added to the embodiment of FIG. 1 and FIG. 2. Referring to FIG. 4, the X-ray tube (100) may include a tubular vacuum vessel (110), a cathode electrode (120), a gate electrode (125), an anode electrode (130), an insulating cover (140), an irradiation port (150), and a conductive cylinder (160). Since the tubular vacuum vessel (110), cathode electrode (120), gate electrode (125), anode electrode (130), insulating cover (140), and irradiation port (150) according to the embodiment of FIG. 4 are substantially identical to the configuration of the embodiment described with reference to FIG. 1 to FIG. 3, the description is omitted below, and the conductive cylinder (160), which is an added component, is described in detail below.

[0042] A conductive cylinder (160) according to one embodiment may be formed to surround the outer surface of an insulating cover (140). The conductive cylinder (160) may surround at least a portion of the outer surface of the first insulating part (141). The conductive cylinder (160) may extend upward from the bottom (141a) of the first insulating part (141). That is, the conductive cylinder (160) may surround the lower portion of the outer surface of the first insulating part (141). The conductive cylinder (160) contacts the outer surface of the first insulating part (141). In one embodiment, the conductive cylinder (160) is formed of a conductive material so as to stabilize the electric field of the internal space (111) of the tubular vacuum vessel (110) by grounding the charge accumulated in the insulating cover (140).

[0043] FIG. 5 is a flowchart illustrating a method (S100) for manufacturing an X-ray tube having a multilayer insulating structure according to one embodiment of the present disclosure (e.g., the X-ray tube (100) of FIG. 1 to 4).

[0044] As described above with reference to FIGS. 1 to 4, the X-ray tube (100) may include a tubular vacuum vessel (110) having a first axis (A1), a cathode electrode (120) disposed at the bottom of the tubular vacuum vessel (110) and including an electron source (121) from which electrons are emitted, an anode electrode (130) disposed at the top of the tubular vacuum vessel (110) and including a tip portion (132) into which electrons emitted from the electron source (121) are irradiated to emit X-rays, an insulating cover (140) including a first insulating portion (141) and a second insulating portion (142), and an irradiation port (150) for extracting X-rays emitted from the tip portion (132) to the outside. In the above configuration of the X-ray tube (100), the configuration excluding the insulating cover (140) and the irradiation port (150) is defined as an X-ray generating unit.

[0045] In a method (S100) for manufacturing an X-ray tube (100) having a multilayer insulation structure according to one embodiment, a step (S110) of manufacturing an X-ray generating unit including a tubular vacuum vessel (110), a cathode electrode (120), and an anode electrode (130) must be performed first. The step (S110) of manufacturing the X-ray generating unit may be performed according to a method of manufacturing an X-ray generating unit by a person with ordinary knowledge in the relevant technical field. The X-ray generating unit manufactured according to the step (S110) of manufacturing the X-ray generating unit is in a state where the tubular vacuum vessel (110), which is cylindrical with respect to the first axis (A1), is exposed to the outside.

[0046] In one embodiment, after arranging the X-ray generating unit so that the first axis (A1) is perpendicular to the bottom surface, a step (S120) of arranging the first insulating part (141) so as to share the first axis (A1) with the tubular vacuum vessel (110) may follow. In the step (S120) of arranging the first insulating part (141), the inner diameter of the first insulating part (141) is larger than the outer diameter of the tubular vacuum vessel (110). That is, the first insulating part (141) must be spaced apart from the outer surface of the tubular vacuum vessel (110). The first insulating part (141) may include a first hole (141H). The first hole (141H) may form part of an irradiation port (e.g., the irradiation port (150) of FIGS. 1 to 4) for extracting X-rays emitted from the tip portion (132) of the cathode electrode (120) to the outside.

[0047] In one embodiment, a step (S125) of inserting a cylindrical mold into a first hole (e.g., the first hole (141H) of FIGS. 2 and 4) of the first insulating part (141) may be performed. The mold according to one embodiment may serve as a frame for being inserted into the first hole (141H) to form an irradiation hole (e.g., the irradiation hole (150) of FIGS. 1, 2 and 4). The mold may be removed after the second insulating part (142) is formed.

[0048] In one embodiment, a step (S130) of filling a fluid insulating liquid between a tubular vacuum vessel (110) and a first insulating part (141) may be performed. A cylindrical mold is formed in the first hole (141H) of the first insulating part (141). The fluid insulating liquid according to one embodiment includes a material that hardens into a solid state by a specific action (e.g., a change in temperature, UV light irradiation, etc.). For example, the insulating liquid may include liquid epoxy, resin, urethane, or silicone, etc. Preferably, the fluid insulating liquid may include a material that has elasticity upon hardening.

[0049] In one embodiment, a step (S140) of curing an insulating liquid filled between a tubular vacuum container (110) and a first insulating part (141) to form a second insulating part (142) may be performed. During the process of curing the insulating liquid, the second insulating part (142) is placed without gaps between the tubular vacuum container (110) and the first insulating part (141), so that the insulating cover (140) is attached to the tubular vacuum container (110) without gaps, thereby increasing the insulation efficiency.

[0050] In one embodiment, after the insulating liquid is cured to form the second insulating part (142), a step (S145) of removing the mold from the first hole (141H) may be performed. As the mold is removed, an irradiation hole (150) may be formed at the location where the mold was placed.

[0051] Although the technical concept of the present disclosure has been described by some embodiments and examples illustrated in the accompanying drawings, it should be understood that various substitutions, modifications, and changes may be made without departing from the technical concept and scope of the present disclosure as understood by those skilled in the art to which the present disclosure pertains. Furthermore, such substitutions, modifications, and changes should be considered to fall within the scope of the appended claims.

Claims

1. A tubular vacuum vessel having a first axis; A cathode electrode disposed at the bottom of the above-mentioned tubular vacuum vessel and comprising an electron source from which electrons are emitted; An anode electrode disposed at the top of the above-mentioned tubular vacuum vessel and comprising a tip portion that emits X-rays when irradiated with electrons emitted from the electron source; An insulating cover comprising a first insulating part sharing the first axis with the tubular vacuum vessel and a second insulating part filled between the outer surface of the tubular vacuum vessel and the inner surface of the first insulating part; and An X-ray tube comprising an irradiation port for extracting the X-rays emitted from the tip portion to the outside.

2. In Paragraph 1, An X-ray tube in which the second insulating portion is formed protruding in a direction spaced apart from the first axis at the periphery of the above investigation area.

3. In Paragraph 1, An X-ray tube, wherein the first insulating part comprises a non-elastic material and the second insulating part comprises an elastic material.

4. In Paragraph 3, An X-ray tube, wherein the first insulating part is made of acrylic or polycarbonate and the second insulating part is made of epoxy or silicone.

5. In Paragraph 1, An X-ray tube further comprising a conductive cylinder surrounding at least a portion of the outer surface of the first insulating part.

6. In Paragraph 5, The above conductive cylinder is an X-ray tube formed to extend upward from the bottom of the first insulating part.

7. In Paragraph 1, X-ray tube, wherein the anode electrode further comprises an anode cap covering at least a portion of the tip portion.

8. In Paragraph 1, The above-mentioned tubular vacuum vessel is an X-ray tube made of ceramic material.

9. A method for manufacturing an X-ray tube having a multilayer insulation structure, A step of manufacturing an X-ray generating unit comprising: a tubular vacuum vessel having a first axis; a cathode electrode disposed at the bottom of the tubular vacuum vessel and including an electron source from which electrons are emitted; and an anode electrode disposed at the top of the tubular vacuum vessel and including a tip portion that emits X-rays when irradiated with electrons emitted from the electron source. A step of arranging the first insulating part such that the first insulating part, having an inner diameter larger than the outer diameter of the tubular vacuum vessel, shares a first axis with the tubular vacuum vessel; A step of filling a fluid-state insulating liquid between the above-mentioned tubular vacuum vessel and the above-mentioned first insulating part; and A method comprising the step of curing the above insulating liquid to form a second insulating part.

10. In Paragraph 9, The above first insulating part includes a first hole, and After the step of arranging the first insulating part, the method further includes the step of inserting a cylindrical mold into the first hole. A method comprising, after the step of forming the second insulating part, further a step of removing the cylindrical mold.

Images