X-ray source

Abstract

The present invention provides an X-ray source including: an anode electrode having a target; a tube-shaped first housing made of an insulating material and having the anode electrode installed at one end; a tube-shaped second housing made of a conductive material and having one end connected to the first housing; and a cathode electrode having an emitter installed at the other end of the second housing and facing the target.

Description

[Technical field]

[0001] The present invention relates to a field emission type X-ray source. [Background technology]

[0002] In general, X-ray sources are widely used in a variety of inspection and diagnostic devices for medical diagnosis, non-destructive testing, chemical analysis, and the like. A field emission X-ray source includes a cathode electrode, a gate electrode, and an anode electrode in a vacuum housing made of an insulating material such as ceramic. An emitter formed of a nanostructure such as CNT (Carbon Nano Tube) is provided on one side of the cathode electrode, a target such as tungsten (W) is provided on one side of the anode electrode facing the cathode electrode, and a gate electrode is provided between the emitter and the target. A field emission X-ray source has a configuration in which electrons are emitted from the emitter by a gate voltage applied to the gate electrode, and the emitted electrons are accelerated toward the anode electrode by the voltage difference between the cathode voltage and the anode voltage applied to the cathode electrode and the anode electrode, respectively, and collide with the target to generate X-rays.

[0003] However, since the housing of conventional field emission X-ray sources is made of insulating materials such as ceramics, if residual charges are trapped, they are difficult to remove, and if this causes arc discharge, the nanostructure emitter can be deteriorated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication No. 10-2021-0083040 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been devised to solve the above-mentioned problems, and its purpose is to provide a field emission X-ray source in which a first housing on the anode electrode side made of a ceramic material and a second housing on the cathode electrode side made of a metal material are joined together as the housing of the field emission X-ray source, so that residual charges in the housing can be easily induced and eliminated in the second housing made of a metal material. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the X-ray source of the present invention is characterized in including an anode electrode portion, a target electrically connected to the anode electrode portion, a first housing made of an insulating material and accommodating at least a portion of the anode electrode portion, an emitter facing the target, a cathode electrode portion electrically connected to the emitter, and a second housing made of a conductive material and forming an X-ray tube together with the first housing.

[0007] The first housing has an inner diameter that increases in a direction from the anode electrode portion toward the cathode electrode portion.

[0008] The housing may further include a flange installed on an outer surface of the second housing, and a window formed in the flange.

[0009] The second housing may further include an insulating spacer, and the cathode electrode part may be fixed to the insulating spacer.

[0010] The cathode electrode portion is disposed inside or outside the second housing.

[0011] The magnitude of the anode voltage applied to the anode electrode portion is proportional to the length of the first housing. Effect of the Invention

[0012] The X-ray source of the present invention has the following advantages.

[0013] The housing is constructed with a joint structure of a first housing on the anode electrode side made of a ceramic material and a second housing on the cathode electrode side made of a metal material. The unique structure of the first and second housings minimizes the possibility of residual charge in the first housing, while the second housing is grounded to quickly remove residual charge, preventing deterioration of the emitter due to discharge arcs.

[0014] In addition, a flange portion is provided on one side of the second housing corresponding to the X-ray irradiation position, and a window is installed thereto to facilitate connection and alignment with other devices. [Brief description of the drawings]

[0015] [Figure 1] 1 is an external perspective view of an X-ray source according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a longitudinal sectional view of FIG. [Diagram 3] 3 is an enlarged cross-sectional view showing parts A, B and C in FIG. 2. [Figure 4] 3 is an enlarged cross-sectional view showing parts A, B and C in FIG. 2. [Diagram 5] 3 is an enlarged cross-sectional view showing parts A, B and C in FIG. 2. [Figure 6] FIG. 11 is an external perspective view of an X-ray source according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a vertical cross-sectional view of FIG. 6. [Figure 8] 8 is an enlarged cross-sectional view of a portion D in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. Regardless of the drawing or the symbol, the same or similar components are given the same reference symbol, and the duplicated description thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed for the sake of ease of specification writing only, and do not have a meaning or role that is different from each other by themselves. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of related known technology may make the gist of the embodiments disclosed in this specification unclear, the detailed description will be omitted. In addition, the accompanying drawings are merely for making the embodiments disclosed in this specification easily understandable, and the technical ideas disclosed in this specification are not limited by the accompanying drawings, and it should be understood that the accompanying drawings include all modifications, equivalents, or alternatives included in the idea and technical scope of the present invention.

[0017] Terms including ordinal numbers, such as "first," "second," etc., may be used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another.

[0018] When a component is said to be "coupled" or "connected" to another component, it should be understood that this means that the component is directly coupled or connected to the other component, but also includes cases where there are other components between them. On the other hand, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components between them.

[0019] A singular expression includes a plural expression unless the context clearly indicates a different meaning.

[0020] In this application, terms such as "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are to be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0021] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings.

[0022] Certain steps may be performed in a different order than that described, when an embodiment can be realized differently. For example, two steps described as successive may be performed substantially simultaneously, or may be performed in the reverse order from that described.

[0023] Meanwhile, the present invention is divided into several embodiments according to specific configurations and functions, and each embodiment will be considered separately below. For convenience of explanation, the contents common to the embodiments will be fully explained in the first embodiment, and the other embodiments will be explained focusing on the differences.

[0024] First embodiment FIG. 1 is an external perspective view of an X-ray source 10 according to a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of FIG. 1, and FIGS. 3, 4 and 5 are enlarged cross-sectional views showing portions A, B and C of FIG. 2.

[0025] With reference to FIGS. 1 and 2, the x-ray source 10 may include an external housing 20 .

[0026] The housing 20 is hollow and tubular, and a vacuum can be created inside.

[0027] The housing 20 can include a first housing 21 on the anode electrode portion 30 side.

[0028] The first housing 21 may have a hollow shape. The first housing 21 may be made of an insulating material. For example, the first housing 21 may be made of a ceramic material.

[0029] The inner surface 21a of the first housing 21 may be skirt-shaped. The skirt shape may be a shape in which the inner diameter becomes larger from top to bottom, that is, from the anode electrode portion 30 to the cathode electrode portion 40 described below.

[0030] 2 and 3, the first housing 21 may include a sleeve 22. The sleeve 22 may be formed to extend downward from a lower end of the first housing 21 toward the cathode electrode unit 40 through the inside of the cylindrical tube 27 toward the cathode electrode unit 40. Thus, the sleeve 22 may cover a joint portion 25 between the lower end of the first housing 21 and the upper end of the cylindrical tube 27. The sleeve 22 may be integral with the first housing 21. An inner surface 22a of the sleeve 22 may be ribbed and extend downward from the inner surface 21a of the first housing 21. This rib shape may maximize the insulation distance. An outer surface 22b of the sleeve 22 may be spaced apart from the cylindrical tube 27. An inclined surface 22c may be formed on the outside of the lower end of the sleeve 22. The inclined surface 22c may be funnel-shaped or dish-shaped such that the distance between the inclined surface 22c and the inner surface of the cylindrical tube 27 becomes gradually narrower as it approaches the first housing 21. This funnel or dish shape allows the charge remaining in the internal space of the housing 20 to be smoothly conducted to the second housing 26, which is the metal side.

[0031] The housing 20 may include a second housing 26 on the side of the cathode electrode unit 40. The second housing 26 may be made of a metal material. The second housing 26 may be grounded.

[0032] The second housing 26 may include a cylindrical tube 27 made of a metal material. The upper end of the cylindrical tube 27 may be joined to the lower end of the first housing 21. The joining may be by brazing, for example.

[0033] The second housing 26 may include a bottom plate 28 made of a metal material. The bottom plate 28 may be a donut-shaped hollow plate. For example, a through hole 28a may be formed in the center of the bottom plate 28. The edge of the bottom plate 28 may be joined to the lower end of the cylindrical tube 27. The joining may be, for example, by brazing and welding.

[0034] 2, the average thickness T of the first housing 21 may be formed to be much thicker than the thickness t of the second housing 26. This is to prevent the ceramic material of the first housing 21 from being dielectrically broken down by the high voltage applied to the anode electrode part 30.

[0035] 2 and 4, the X-ray source 10 may include an anode electrode portion 30 disposed at one end of the first housing 21.

[0036] The anode electrode part 30 may include an anode electrode bar 31 disposed at the center of the inner surface of the first housing 21. The anode electrode bar 31 may be made of a metal material.

[0037] The anode electrode unit 30 may include a support 33 disposed outside the upper end of the first housing 21. The support 33 may be made of a metal material. The support 33 may be integrally formed with the upper end of the anode electrode bar 31. The diameter of the support 33 may be larger than the diameter of the anode electrode bar 31 and smaller than the minimum inner diameter of the first housing 21. The support 33 may include a support base 35 made of a metal material. The support base 35 may be formed on the outer circumferential surface of the support 33. The support base 35 may have a U-shaped bridge structure. The support base 35 may include a horizontal support base 35a. The horizontal support base 35a may protrude horizontally outward from the outer circumferential surface of the support 33. The support base 35 may include a vertical support base 35b. The vertical support base 35b may protrude downward from the horizontal support base 35a. A lower end of the vertical support base 35b may be joined to the upper end of the first housing 21. A space 36 may be formed between the vertical support 35b and the outer circumferential surface of the support 33. The support 35 and the space 36 may enable the anode electrode unit 30 to be stably fixed to the first housing 21 despite the difference in thermal expansion coefficient between the different materials, the anode electrode unit 30 made of a metal material and the first housing 21 made of a ceramic material.

[0038] The anode electrode unit 30 may include a target mounting unit 37 made of a metal material. The target mounting unit 37 may be integrally formed at the lower end of the anode electrode bar 31. A lower surface 37a of the target mounting unit 37 is inclined obliquely toward the window 50. A target 39 may be bonded to the lower surface 37a of the target mounting unit 37. The target 39 may emit X-rays to the window 50 by being struck by accelerated electrons. The target 39 may be made of tungsten (W), copper (Cu), molybdenum (Mo), cobalt (Co), chromium (Cr), iron (Fe), silver (Ag), tantalum (Ta), yttrium (Y), or the like. For example, the target 39 may be made of tungsten (W), which has a high melting point and excellent X-ray emission efficiency.

[0039] 2 and 5, the X-ray source 10 may include a cathode electrode unit 40. The cathode electrode unit 40 may be disposed in the through-hole 28a of the bottom plate 28 of the second housing 26 at a distance from the through-hole 28a. Thus, the cathode electrode unit 40 may be electrically insulated from the second housing 26 made of a metal material.

[0040] The cathode electrode portion 40 may include a cathode electrode 41. The cathode electrode 41 may be disposed on the outside of the bottom plate 28 of the second housing 26.

[0041] The cathode electrode 41 may have a convex shape. The cathode electrode 41 may include a cathode body 41a made of a metal material. A nanoscale emitter (not shown), such as a carbon nano tube (CNT) or a metal nano tip, may be disposed on the surface of the cathode body 41a.

[0042] The cathode electrode 41 may include a cathode flange 41b made of a metal material. The cathode flange 41b may be integrally formed on the lower side of the cathode body 41a.

[0043] The cathode electrode part 40 may include a gate electrode 42. The gate electrode 42 may be provided on an upper surface of the cathode body 41a at a distance therefrom. Thus, the gate electrode 42 is electrically insulated from the cathode electrode 41. The gate electrode 42 may be in the form of a mesh.

[0044] The gate electrode 42 may include a focus portion 43. The focus portion 43 may include a focus tube 43a. The gate electrode 42 may be joined to a lower end of the focus tube 43a. The focus tube 43a may guide electrons emitted from the emitter and passing through the gate electrode 42 to be focused. The focus portion 43 may include a focus flange 43b. The focus flange 43b may be formed on the lower side of the focus tube 43a. A first step portion 43b' may be formed on an upper surface of the focus flange 43b. The first step portion 43b' may be formed to be recessed downward. A second step portion 43b" may be formed on a lower surface of the focus flange 43b. The second step portion 43b" may be formed to be recessed upward.

[0045] The cathode electrode section 40 may include a focus electrode 44. The focus electrode 44 can perform secondary focusing on the electrons focused in the focus section 43.

[0046] The focus electrode 44 may include a focus electrode hollow plate 44a. The inner diameter of the focus electrode hollow plate 44a may be the same as that of the focus tube 43a, or may be slightly larger.

[0047] The focus electrode 44 may include a focus electrode sidewall 44b. The focus electrode sidewall 44b may extend downward from the lower surface of the edge of the focus electrode hollow plate 44a. The inner diameter of the focus electrode sidewall 44b may be approximately the same as the outer diameter of the focus flange 43b.

[0048] The cathode electrode portion 40 may include a tubular first insulating spacer 45. The first insulating spacer 45 may be provided between the cathode electrode 41 and the focus portion 43. That is, the first insulating spacer 45 may be provided between the cathode flange 41b and the second step portion 43b″. The first insulating spacer 45 may separate and electrically insulate the cathode electrode 41 and the gate electrode 42.

[0049] The cathode electrode section 40 may include a tubular second insulating spacer 46. The second insulating spacer 46 may be provided between the focus electrode 44 and the bottom plate 28 of the second housing 26, and between the focus electrode 44 and the focus portion 43. That is, the lower surface of the second insulating spacer 46 is placed on the step portion 28b of the bottom plate 28 and the first step portion 43b', and the upper surface of the second insulating spacer 46 may receive the focus electrode side wall 44b. The second insulating spacer 46 may separate the focus portion 43 of the gate electrode 42 from the focus electrode 44, and may fix the cathode electrode section 40 to the second housing 26. This allows the gate electrode 42 and the focus electrode 44 to be electrically insulated from each other.

[0050] These components may be joined together to form an assembly in the cathode electrode unit 40. The cathode electrode unit 40 of this assembly structure may be joined to the second housing 26 by filler welding the second insulating spacer 46 to the stepped portion 28b of the bottom plate 28.

[0051] The X-ray source 10 may include a window 50. The window 50 may be provided inside a flange portion 51 installed on one side of the cylindrical tube 27 of the second housing 26 facing the target 39.

[0052] The flange portion 51 may include a horizontal pipe 53. The horizontal pipe 53 may be disposed on the outer surface of one side of the cylindrical pipe 27.

[0053] The flange portion 51 may include a flange 55. The flange 55 may be provided at an end of the horizontal pipe 53.

[0054] The window 50 may be provided at the interface of the horizontal pipe 53 and the flange 55 .

[0055] Such a flange portion 51 not only provides the window 50 but also provides convenience in connection and alignment with other devices.

[0056] A cathode voltage can be applied to the cathode electrode 41, an anode voltage to the anode electrode section 30, a gate voltage to the gate electrode 42, and a focus voltage to the focus electrode 44. When electrons are emitted from the emitter by the gate voltage applied to the gate electrode 42, the high potential difference between the cathode voltage and the anode voltage applied to the cathode electrode 41 and the anode electrode section 30 causes the electrons to pass through the mesh of the gate electrode 42 and accelerate toward the anode electrode section 30, where they collide with the target 39 and generate X-rays. The generated X-rays are transmitted through the window 50 and irradiated to the outside. During this process, the focus electrode 44 focuses the electrons that pass through the mesh of the gate electrode 42 and head toward the anode electrode section 30 onto the target 39.

[0057] On the other hand, the distance between the target 39 and the cathode electrode 41 can be fixed in order to form an electric field.

[0058] The X-ray source 10 according to the first modified example of this embodiment may be, for example, a so-called single power supply type in which the cathode voltage applied to the cathode electrode is at ground potential and the anode voltage applied to the anode electrode unit 30 is at positive potential. In this case, a very high voltage is applied to the anode electrode unit 30. The anode voltage may be, for example, +120 kV or more. Therefore, the length of the anode electrode bar 31 and the first housing 21 is increased to strengthen the insulation of the first housing 21, and the height of the second insulating spacer 46 is adjusted to dispose the cathode electrode 41 outside the lower end of the second housing 20, thereby maintaining the distance between the target 39 and the cathode electrode 41.

[0059] Second Variation FIG. 6 is an external perspective view of an X-ray source 100 according to a second modified example of the preferred embodiment of the present invention, FIG. 7 is a vertical sectional view of FIG. 6, and FIG. 8 is an enlarged sectional view of a portion D of FIG.

[0060] The X-ray source 100 according to the second modified example of the present embodiment may be a dual power supply type in which the anode voltage and the cathode voltage indicate a positive potential and a negative potential, respectively. For example, the anode voltage may be +60 kV and the cathode voltage may be −60 kV.

[0061] 2 and 7, the X-ray source 100 according to the second modified example has almost the same structure as the X-ray source 10 according to the first modified example, but since the anode voltage is relatively low, the dielectric strength required for the first housing 21 is relatively small. Therefore, the length of the first housing is relatively short, and the cathode electrode 41 is disposed inside the second housing 126 to maintain the distance between the target 39 and the cathode electrode 41. For this purpose, a tubular third insulating spacer 147 can be added inside the second housing 126.

[0062] Hereinafter, when the structure and function are the same as those of the X-ray source 10 according to the first modified example, the same reference numerals are used and detailed description thereof will be omitted.

[0063] 6 and 7, the x-ray source 100 can include an external housing 120.

[0064] The housing 120 may include a first housing 121 on the anode electrode unit 130 side and a second housing 126 on the cathode electrode unit 140 side. The first housing 121 may be made of an insulating material, for example a ceramic material, and the second housing 126 may be made of a metal material. Compared to the first modified example, the first housing 121 may be relatively shorter in length (height).

[0065] A sleeve 122 may be formed at a lower end of the first housing 121 to extend downward into the second housing 126. The sleeve 122 may be formed of a material that is integral with the first housing 121.

[0066] An inner surface 121a of the first housing 121 and an inner surface 122a of the sleeve 122 may be skirt-shaped with an inner diameter that increases downward.

[0067] An outer surface 122b of the sleeve 122 may be spaced apart from the cylindrical tube 127 of the second housing 126. An inclined surface 122c may be formed on the outside of the lower end of the sleeve 122. The inclined surface 122c may be funnel-shaped or dish-shaped so as to gradually narrow with the inner surface of the cylindrical tube 127 as it approaches the first housing 121.

[0068] The second housing 126 may include a cylindrical tube 127 and a bottom plate 128. A through hole 128a may be provided at the center of the bottom plate 128.

[0069] Referring to FIG. 7, the X-ray source 100 can include an anode electrode portion 130 . The anode electrode portion 130 can be disposed at the center of the inner surfaces of the first housing 121 and the sleeve 122 .

[0070] The anode electrode unit 130 may include an anode electrode bar 131 , and a support unit 33 and a target mounting unit 37 formed on the upper and lower ends of the anode electrode bar 131 .

[0071] The anode electrode bar 131 can be covered by a first housing 121 and a sleeve 122 .

[0072] The anode electrode bar 131 of the dual power supply may be relatively shorter in length (height) than the anode electrode bar 31 of the single power supply.

[0073] The outer circumferential surface of the support part 33 may include a support stand 35. The support stand 35 may be U-shaped and may include a horizontal support stand 35a and a vertical support stand 35b. A space 36 that allows for thermal expansion may be formed between the vertical support stand 35b and the outer circumferential surface of the support part 33.

[0074] The lower surface 37a of the target mounting portion 37 is an inclined surface that is inclined obliquely toward the window 50 side, and the target 39 can be bonded to this inclined surface.

[0075] 7 and 8, the X-ray source 100 may include a cathode electrode portion 140. The cathode electrode portion 140 may be disposed within the second housing 126.

[0076] The cathode electrode portion 140 may include a cathode electrode 41. The cathode electrode 41 may be disposed inside the housing 20.

[0077] The cathode electrode 41 has a convex shape and can include a cathode body 41a and a cathode flange 41b. An emitter (not shown) can be disposed on the upper surface of the cathode body 41a.

[0078] The cathode electrode section 140 may include a gate electrode 42 provided on the upper surface of the cathode body 41a. The gate electrode 42 may be in a mesh shape.

[0079] The cathode electrode portion 140 can include a focus portion 43 .

[0080] The focus unit 43 may include a focus tube 43a and a focus flange 43b. The gate electrode 42 may be joined to a lower end of the focus tube 43a. A first step portion 43b' may be formed on an upper surface of the focus flange 43b, the first step portion 43b' being recessed downward. A second step portion 43b" may be formed on a lower surface of the focus flange 43b, the second step portion 43b" being recessed upward.

[0081] The cathode electrode portion 140 may include a focus electrode 144 .

[0082] The focus electrode 144 may include a focus electrode hollow plate 144a. The inner diameter of the focus electrode hollow plate 144a may be the same as or slightly larger than that of the focus tube 43a.

[0083] The focus electrode 144 may include a focus electrode sidewall 144b. The focus electrode sidewall 144b may extend downward from a lower surface of the focus electrode hollow plate 144a. The inner diameter of the focus electrode sidewall 144b may be larger than the outer diameter of the focus tube 43a. The focus electrode sidewall 144b may be inserted into the outer circumferential surface of the focus tube 43a. A step portion 144b' recessed upward may be formed on the inner side of the lower end of the focus electrode sidewall 144b.

[0084] The focus electrode 144 may include a support flange 144c. The support flange 144c may be provided so as to extend outward from the outer circumferential surface of the focus electrode hollow plate 144a. A locking step 144c' may be provided at an end of the support flange 144c. The locking step 144c' may be provided so as to extend downward from the end of the support flange 144c.

[0085] The cathode electrode portion 140 may include a first insulating spacer 45. The first insulating spacer 45 may be provided between the cathode electrode 41 and the focus portion 43. That is, the first insulating spacer 45 may be provided between the cathode flange 41b and the second step portion 43b″. The first insulating spacer 45 separates the cathode electrode 41 and the gate electrode 42 to electrically insulate them from each other.

[0086] The cathode electrode unit 140 may include a second insulating spacer 146. The second insulating spacer 146 may be provided between the focus electrode 144 and the focus unit 43. That is, the lower surface of the second insulating spacer 146 may be provided between the first step portion 43b' and the step portion 144b'. The second insulating spacer 146 separates the focus unit 43 and the focus electrode 144 to electrically insulate them from each other.

[0087] The X-ray source 100 may include a third insulating spacer 147. The third insulating spacer 147 may be provided between the focus electrode 144 and the bottom plate 128. That is, the third insulating spacer 147 may be provided between the locking step 144c' and the step portion 128b of the bottom plate 128. The third insulating spacer 147 may insulate the cathode electrode 41 from the second housing 126 and fix the cathode electrode part 140 to the second housing 126. The third insulating spacer 147 may be in the form of a skirt whose diameter increases from the top to the bottom. Therefore, the third insulating spacer 147 may lead residual charges in the housing to the second housing 127 made of a metal material.

[0088] These components may be joined together to form an assembly in the cathode electrode unit 140. In the cathode electrode unit 140 of this assembly structure, the lower end of the third insulating spacer 147 may be joined to the step portion 128b of the bottom plate 128.

[0089] The x-ray source 100 may include a window 50 .

[0090] The window 50 may be provided in a flange portion 51. The flange portion 51 may include a horizontal tube 53 and a flange 55. The window 50 may be provided at the interface between the horizontal tube 53 and the flange 55.

[0091] On the other hand, the distance between the target 39 and the cathode electrode 41 can be fixed in order to form an electric field.

[0092] In the case of the X-ray source 100 in which a negative potential and a positive potential are applied to the cathode electrode 41 and the anode electrode unit 130, respectively, the anode voltage is relatively low, and therefore the dielectric strength required for the first housing 21 is relatively small. Therefore, by disposing the cathode electrode 41 inside the housing 120, the length of the anode electrode bar 131 and the first housing 121 can be reduced and the length (or height) of the third insulating spacer 147 can be increased, thereby keeping the distance between the target 39 and the cathode electrode 41 constant.

[0093] For example, comparing FIG. 2 and FIG. 7, the first housing 121 and the anode electrode rod 131 of the X-ray source 100 of FIG. 7 are shorter in length than the first housing 21 and the anode electrode rod 31 of the X-ray source 10 of FIG. 2, but the second housing 126 of the X-ray source 100 of FIG. 7 can be formed to be longer in length than the second housing 26 of the X-ray source 10 of FIG. 2.

[0094] The above-mentioned embodiment of the present invention or other embodiments are not mutually exclusive or distinct, and the configurations or functions of the above-mentioned embodiment of the present invention or other embodiments may be used together or combined.

[0095] It is obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. The above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. [Explanation of symbols]

[0096] 10 X-ray source 20, 120 Housing 21, 121 Housing 22, 122 sleeve 25 Joint site 26, 126 Second Housing 27, 127 Cylindrical tube 28, 128 bottom plate 30, 130 Anode electrode part 31, 131 Anode electrode 33 Support part 35 Support stand 37 Target installation section 39 Target 40 Cathode electrode part 41 Cathode electrode 42 Gate electrode 43 Focus section 44, 144 Focus electrode 45 First insulating spacer 46, 146 Second insulating spacer 50 Windows 51 Flange 53 Horizontal pipe 55 Flange 100 X-ray source 147 Third insulating spacer

Claims

1. an anode electrode portion; a target electrically connected to the anode electrode portion; a first housing made of an insulating material and accommodating at least a portion of the anode electrode portion; an emitter facing the target; a cathode electrode portion electrically connected to the emitter; an X-ray source including a second housing made of a conductive material, the second housing forming an X-ray tube together with the first housing, the second housing being grounded;

2. The X-ray source according to claim 1 , wherein the first housing has an inner diameter that increases in a direction from the anode electrode portion toward the cathode electrode portion.

3. a flange disposed on an outer surface of the second housing; 10. The x-ray source of claim 1, further comprising a window formed in the flange.

4. the second housing further includes an insulating spacer; The X-ray source according to claim 1 , wherein the cathode electrode portion is fixed to the insulating spacer.

5. The X-ray source according to claim 4 , wherein the cathode electrode portion is disposed inside or outside the second housing.

6. 2. The X-ray source according to claim 1, wherein the magnitude of the anode voltage applied to the anode electrode portion is proportional to the length of the first housing.

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