JPH1027562A - X-ray tube, its manufacture, and device for its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray device which is stable with little residual gas therein by providing a high frequency heating element, which is made of a material different from that for the anode of the X-ray tube, on the surface of the anode. SOLUTION: An X-ray tube 13 comprises a vacuum container 16, a cathode 17 located at one end inside the vacuum container 16, an anode 18 located at the other end, and the like, the cathode 17 and the anode 18 being insulated from each other by the vacuum container 16. A filament 19 for heating time cathode 17 is provided inside the cathode 17 and connected to a lead terminal 20. The anode 18 comprises a rod-shaped main body part 18a, an anode target 18b provided in front of the part 18a, e.g. on an end surface, and the like, with the anode target 18b located within the vacuum container 16 and its rear located outside the vacuum container 16, and with the main body part 18a sealed to the sealing part 16a of the vacuum container 16. A high frequency heating element 21 made of a magnetic substance different from that for the anode 18 is formed in a cylindrical shape on the outer peripheral surface of the main body part 18a except the front and rear end surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tube in which the degree of vacuum in the tube is improved and the amount of residual gas is small, and a method and apparatus for manufacturing the same.

[0002]

2. Description of the Related Art A conventional X-ray tube will be described with reference to FIG. 6 taking a fixed anode X-ray tube as an example. Reference numeral 61 denotes a vacuum container constituting a part of the X-ray tube, and the inside of the vacuum container 62 is maintained at a vacuum. A cathode 62 is provided at one end in the vacuum vessel 61, and an anode 6 is provided at the other end of the vacuum vessel 61.
The cathode 62 and the anode 63 are insulated by the vacuum vessel 61. Inside the cathode 62, a filament 64 for heating the cathode 62 is provided. The filament 64 is connected to the lead terminal 65.

The anode 63 has a rod-shaped main body 63a,
In addition, the main body 63a is constituted by an anode target 63b provided in front of, for example, a tip portion of the main body 63a, and the main body 63a is sealed by a sealing portion 61a which is a part of the vacuum vessel 61. The rear of the main body 63 a of the anode 63 is located outside the vacuum vessel 61. When manufacturing the X-ray tube having the above-described configuration in which the anode target 63b is irradiated with the electron beam 66 generated by the cathode 62 and generates X-rays, one of the manufacturing processes includes an exhausting process. The evacuation step includes, for example, three heating steps. A first heating step of heating the entire X-ray tube with a gas furnace or an electric furnace, a second heating step of passing a current through the filament 64 to heat the cathode 62, and irradiating the anode target 63a with the electron beam 66 to form the anode 63 This is a third heating step of heating. These first to third heating steps are sequentially performed. In these heating steps, the components of the X-ray tube are heated so that the residual gas is reduced, so that an X-ray tube that operates stably in a high vacuum can be realized.

In the case of a fixed anode X-ray tube, an anode target 63 made of a refractory metal irradiated with an electron beam 66 is used.
b is embedded in the tip of the rod-shaped main body 63a. At this time, the heat of the anode target 63b heated by the irradiation of the electron beam 66 is released to the outside.
The main body portion 63a is usually made of copper or the like having good heat conductivity.

[0005]

The evacuation process of the X-ray tube is as follows.
As described above, the first heating step heats the entire X-ray tube, the second heating step heats the cathode, and the third heating step heats the anode. In each of these heating steps, different components of the X-ray tube are mainly heated for each heating step. In the first heating step, the vacuum vessel is mainly heated, and in the second and third heating steps,
The respective cathode and anode are mainly heated. For this reason, in the evacuation process of the X-ray tube, the temperature of the cathode and the anode is not at the same time suitable for gas release.

[0006] As described above, for example, in the second heating step, the cathode is mainly heated and the anode is at a low temperature.
Therefore, gas discharged from the cathode may be adsorbed on the anode target. In the third heating step, the anode is heated and the temperature of the cathode is lowered. Therefore, the gas discharged from the anode is adsorbed on the cathode. As described above, a gas catch ball occurs between the cathode and the anode, and the X-ray tube is not sufficiently exhausted. If the exhaust is not sufficient, the withstand voltage characteristics deteriorate, for example, a discharge occurs when a high voltage is applied to the electrode of the X-ray tube.

Here, a third heating step of heating the anode will be described with reference to FIG. In FIG. 7, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted. The vacuum vessel 61 is connected to a vacuum pump 71, and a high voltage power supply 72
A high voltage of kV is applied. A filament power supply 73 is connected between the filaments 64 of the cathode 62, and an electron beam 66 is supplied by electric power supplied from the filament power supply 73.
And irradiates the anode target 63b. Thus, the anode target 63b generates the X-ray 74. At this time, the anode target 63b generates heat and releases gas.

By the way, when the anode target 63b is heated, for example, in a heating step of the cathode 62, for example, there is a catch ball of gas or the like. Is affected by the gas emitted from the anode 63, and a stable discharge cannot be maintained. In such a case, a kaminari discharge may occur and the X-ray tube may be damaged. When the anode target 63a is heated by irradiation with the electron beam 66, X-rays 74 are generated from the anode 63, so equipment for shielding the X-rays is required.

In order to eliminate the above-mentioned problem, a method of directly heating a vacuum vessel, a cathode, and an anode using induction heating by high frequency is considered. However, in the case of a fixed anode X-ray tube or the like, the rod-shaped main body of the anode is made of copper or a copper alloy to improve heat conduction. Copper or copper alloys have low electrical resistance and are diamagnetic, so induction heating by high frequency cannot be expected much. For this reason, if the anode is heated to the target temperature, other metals, for example, the cathode are heated more than necessary, which may cause breakage.

An object of the present invention is to solve the above-mentioned drawbacks and to provide an X-ray tube having a small amount of residual gas, and a method and an apparatus for manufacturing the same.

[0011]

According to the present invention, there is provided a vacuum vessel constituting a part of an X-ray tube, a cathode arranged in the vacuum vessel for emitting an electron beam, and an anode irradiated with the electron beam. In an X-ray tube including a target provided in front and an anode positioned outside the outer container, a high-frequency heating element made of a material different from the anode is provided on an outer peripheral portion of the anode.

The high-frequency heating element has a thickness of 1 mm or less.

The high-frequency heating element is provided on the outer peripheral portion of the anode by welding, brazing, or plating.

Further, according to the method of manufacturing an X-ray tube of the present invention, a cathode is fixed to one end in a vacuum vessel constituting a part of the X-ray tube,
A step of fixing an anode having a high-frequency heating element provided on an outer peripheral portion to the other end of the vacuum vessel, a step of disposing the vacuum vessel to which the cathode and the anode are fixed in a heat dissipation prevention tank, And heating the high-frequency heating element provided on the outer peripheral portion of the device with a high-frequency coil.

Further, according to the method of manufacturing an X-ray tube of the present invention, a cathode is fixed to one end in a vacuum vessel constituting a part of the X-ray tube,
Fixing an anode to the other end of the vacuum vessel, attaching a high-frequency heating element to the anode portion located outside the vacuum vessel, and heating the high-frequency heating element attached to the anode section with a high-frequency coil And removing the high-frequency heating element attached to the anode part from the anode part.

The high-frequency heating element is formed in a rod shape having a diameter of 6 mm or less.

The high-frequency heating element has a cylindrical portion having an outer diameter of at least 6 mm and a thickness of at most 1 mm.

Further, the apparatus for manufacturing an X-ray tube according to the present invention includes a tubular high-frequency heating element surrounding a periphery of an X-ray tube in which a cathode and an anode target are arranged inside an outer container, and a high-frequency heating element for heating the high-frequency heating element. And a coil.

The method for manufacturing an X-ray tube according to the present invention comprises the steps of: heating a cylindrical high-frequency heating element surrounding a periphery of the X-ray tube in which a cathode and an anode are arranged inside a vacuum vessel with a high-frequency coil; And a step of irradiating the substrate with an electron beam.

The apparatus for manufacturing an X-ray tube according to the present invention further comprises a cylindrical high-frequency heating element surrounding the periphery of the X-ray tube having a cathode and an anode disposed inside the outer container; A high-frequency heating element attached to the anode part, and a high-frequency coil for heating the high-frequency heating element attached to the cylindrical high-frequency heating element and the anode part are provided.

In addition, a heat dissipation prevention tank made of an electric insulator for housing the X-ray tube and the tubular high-frequency heating element is provided.

In addition, a heat dissipation prevention tank made of an electrically insulating material for accommodating the X-ray tube and the cylindrical high-frequency heating element is provided, and the inside of the heat dissipation prevention tank has an inert gas atmosphere.

Further, a cylindrical high-frequency heating element is disposed so as to surround the cathode-side end of the X-ray tube.

The high-frequency heating element is iron or an iron-based alloy, nickel or a nickel alloy, tungsten or a tungsten alloy, molybdenum or a molybdenum alloy, or tantalum or a tantalum alloy.

According to the above configuration, the high-frequency heating element made of a material different from the anode, for example, iron, an iron-based alloy, nickel, or a nickel alloy is provided on the surface of the anode. According to this configuration, the high-frequency heating element can be heated by induction heating using the high-frequency coil, and the anode can be heated by the heat generated by the high-frequency heating element. Therefore,
In the evacuation process of the X-ray tube, the cathode and anode of the X-ray tube can be simultaneously heated using a high-frequency coil. For this reason,
There is no catch of gas between the cathode and the anode, and an X-ray tube with less residual gas can be realized. Further, since the anode does not generate X-rays, no device for shielding X-rays is required.
Further, the heating temperature of the anode can be adjusted by adjusting the area and thickness of the high-frequency heating element, and the heating temperature of the cathode and the anode can be balanced.

When the high-frequency heating element is thick, the surface heating effect of the induction heating is impaired, and the ability of the anode to release the generated heat to the outside is reduced. For this reason, in the present invention, the thickness of the high-frequency heating element is, for example, 1 mm or less.

In the method of manufacturing an X-ray tube according to the present invention, a high-frequency heating element is attached to an anode located outside the vacuum vessel, and the high-frequency heating element is heated by a high-frequency coil to heat the anode. The high-frequency heating element attached to the anode is removed from the anode. According to this method, the high-frequency heating element is detachable from the anode part, and the high-frequency heating element is attached to the anode part only when the anode is heated. Therefore, the anode can be heated using the high-frequency coil without changing the structure of the X-ray tube during the evacuation step or the like.

Further, the apparatus for manufacturing an X-ray tube according to the present invention comprises: a metal tubular high-frequency heating element surrounding a periphery of an X-ray tube in which a cathode and an anode target are arranged inside a vacuum vessel; And a high-frequency coil for heating, for example,
The high-frequency heating element is arranged so as to surround the cathode portion of the X-ray tube. In the case of this configuration, the high-frequency heating element is heated by the high-frequency coil, and the heat can simultaneously heat the vacuum vessel, the cathode, and the anode that constitute a part of the X-ray tube. Therefore, there is no catch of gas between the cathode and the anode,
An X-ray tube with less residual gas can be realized.

When the X-ray tube and the high-frequency heating element are housed in the heat dissipation preventing tank, the entire inside of the heat dissipation preventing tank is heated by the high-frequency heating element. Therefore, the vacuum vessel, the cathode, and the anode can be heated at the same time, there is no gas catch between the cathode and the anode, and an X-ray tube with less residual gas can be realized. Further, the high-frequency heating element disposed so as to surround the cathode portion of the X-ray tube has a function of shielding high-frequency waves. Therefore, by changing the relative positional relationship between the high-frequency heating element and the cathode, the high-frequency signal applied to the cathode can be controlled,
The heating temperature of the cathode can be controlled and set to an appropriate temperature.

Further, when the inside of the heat dissipation prevention tank is set to an inert gas atmosphere, oxidation of the high frequency heating element can be prevented. At this time, graphite or the like can be used as the high-frequency heating element.

The heating by the high-frequency heating element and the heating by the irradiation of the electron beam are used together. The focal point of the anode target where the electron beam hits is approximately 20
The temperature rises to 00 ° C. Therefore, the anode can be set to a high temperature by using the heating by the electron beam irradiation, and more reliable exhaust can be performed.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. 1 taking a fixed anode X-ray tube as an example. FIG. 1 is a cross-sectional view showing an evacuation process in which an X-ray tube is arranged in a heat dissipation prevention tank. Reference numeral 11 denotes a heat dissipation prevention tank, and the heat dissipation prevention tank 11 includes a cap 11a made of quartz and a base 11b, and a space is formed therein. Heat dissipation prevention tank 1
A high-frequency coil 12 is arranged in a spiral shape on the outside of 1. An X-ray tube 13 is arranged in the heat dissipation prevention tank 11,
The lower end of the wire tube 13 is connected to an exhaust pump 15 through an exhaust tube 14.

The X-ray tube 13 includes a vacuum vessel 16, a cathode 17 located at one end of the vacuum vessel 16, and an anode 18 located at the other end. The cathode 17 and the anode 18 are insulated by the vacuum vessel 16. ing. Inside the cathode 17, a filament 19 for heating the cathode 17 is provided.
9 is connected to the lead terminal 20.

The anode 18 is connected to the rod-shaped main body portion 18.
a, and an anode target 18b provided in front of the main body portion 18a, for example, on the front end surface. The front of the main body portion 18a is located inside the vacuum container 16, and the rear is outside the vacuum container 16.
Is sealed by the sealing portion 16a. A high-frequency heating element 21 made of a magnetic material such as iron, an iron-based alloy, nickel, or a nickel alloy is formed in a cylindrical shape, for example, on the entire outer surface of the main body portion 18a except for the front end face and the rear end face. Have been.

In the above configuration, when the X-ray tube 13 is evacuated, a current is applied to the high-frequency coil 12 to heat the cathode 17 and also to heat the high-frequency heating element 21, and the heat is used to heat the anode 18. . The inside of the X-ray tube 13 is exhausted by an exhaust pump 15. At this time, since the body portion 18a of the anode 18 is made of copper and a copper alloy having good thermal conductivity, induction heating by high frequency is small. However, the high-frequency heating element 21 fixed to the outer peripheral portion of the anode 18 by brazing or the like generates heat, whereby the anode 18 is heated. In this method, the cathode 17 and the anode 18 are simultaneously heated and evacuated. Therefore, there is no catching ball of gas between the cathode 17 and the anode 18, the degassing effect is improved, and the gas is exhausted well. As a result, a stable X-ray tube with little residual gas can be realized. The heating temperature of the anode 18 can be adjusted by changing the thickness of the high-frequency heating element 21. Therefore, by adjusting the thickness of the high-frequency heating element 21 and the current flowing through the high-frequency coil 12,
And the anode 18 can be simultaneously set to an appropriate temperature.

If the high-frequency heating element 21 is thick, the surface heating effect of induction heating is impaired. In addition, the ability to release the heat generated at the anode 18 to the outside is reduced. Therefore, the thickness of the high-frequency heating element 21 is desirably 1 mm or less. Further, in the above-described embodiment, the high-frequency heating element is brazed to the surface of the anode. However, when the high-frequency heating element is fixed to the anode, a film forming method such as plating or ion plating may be used.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 2, portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

In the embodiment shown in FIG. 1, a high-frequency heating element 21 made of a magnetic material is formed on the outer periphery of the rod-shaped main portion 18a of the anode 18 by brazing or a film forming technique. In this embodiment, when the X-ray tube is placed in the heating tank and evacuated, the high-frequency heating element 21 such as iron or an iron-based alloy can be attached to and detached from the anode 18 located outside the vacuum vessel 16, and , Mounted so as to be thermally coupled.

For example, the high-frequency heating element 21 is entirely cylindrical 2
1a, and the center of the cylinder 21a is a wall 21b.
And has a H-shaped cross section. Cylinder 21
The inner diameter of the portion a is made substantially equal to the outer diameter of the rear end of the anode 18,
The rear end of the anode 18 is fitted into the cylinder 21 a of the high-frequency heating element 21. Then, it is fixed to the rear end face of the anode 18 by, for example, an anode terminal 18c using a through hole formed in the wall 21b. In this case as well, the high-frequency heating element 21 is heated by passing a current through the high-frequency coil 12, and this heat is transmitted to the anode 18 through the wall 21 b of the high-frequency heating element 21 and heats the anode 18. In addition,
At the stage where the evacuation process is completed, the high-frequency heating element 21
Removed from 8.

The above-described high-frequency heating element 21 is induction-heated by the high-frequency coil 12 and may be any element that transfers this heat to the anode 18. Therefore, as shown in FIG. 3A, the high-frequency heating element 21 may be made of a magnetic material such as iron or an iron-based alloy in a rod shape, and the tip may be screwed into the end of the anode 18 and fixed. it can. Alternatively, as shown in FIG. 3B, the entire high-frequency heating element 21 may be formed in a cylindrical shape, and the rear end of the anode 18 may be fitted inside the cylindrical portion. Also in these structures, the high-frequency heating element 21 is heated by the high-frequency coil, and the heat is transmitted to the anode 18 by radiation or conduction to heat the anode 18. Note that the high-frequency heating element 21 shown in FIGS.
When the wire tube is placed in the heat dissipation prevention tank and exhausted, the anode 18
And is removed from the anode 18 when the evacuation process is completed. 3, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted.

When the high frequency heating element 21 is rod-shaped as shown in FIG. 3A, the outer diameter D is desirably 6 mm or less. In addition, as shown in FIG.
When 1 is a cylinder or a cylinder having an H-shaped cross section, the outer diameter D is desirably 6 mm or more, and the thickness t of the tubular portion is desirably 1 mm or less.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 4, the same reference numerals are given to portions corresponding to FIG. 1 and FIG.
A duplicate description is partially omitted.

For example, the X-ray tube 13 whose inside is evacuated is placed in the heat dissipation prevention tank 11, and the cathode 1 of the X-ray tube 13 is
A cylindrical high-frequency heating element 41 having a height surrounding seven
It is installed around the wire tube 13. And the X-ray tube 13
A spiral high-frequency coil 12 is provided outside the heat dissipation prevention tank 11 at a position from the center to the anode 18.

In this configuration, a current flows through the high-frequency coil 12, and the cathode 17 and the high-frequency heating element 41 are heated.
At this time, since the inside of the heat dissipation preventing tank 11 is a substantially closed space, when the high-frequency heating element 41 is heated, the atmosphere around the vacuum vessel 16 is heated. The heated atmosphere rises along the side surface of the vacuum vessel 16 and descends along the inner surface of the heat dissipation prevention tank 11. In this way, the closed atmosphere inside the heat dissipation prevention tank 11 is heated to a target temperature and circulates inside the X-ray tube 1.
The area around 3 rises to a uniform temperature.

The high-frequency heating element 41 has a function of shielding high-frequency waves applied to the cathode 17. Therefore, if the relative position between the high-frequency heating element 41 and the cathode 17 is changed, the heating temperature of the cathode 17 can be adjusted, and good components between the components of the X-ray tube 13, for example, the vacuum vessel 16, the cathode 17 and the anode 18 can be obtained. Heating balance can be obtained. Therefore, the temperatures of the anode 18, the cathode 17, the vacuum vessel 16, and the like can be set in any combination.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 5, parts corresponding to those in FIGS. 1, 2, and 4 are denoted by the same reference numerals, and overlapping description is partially omitted. In this embodiment, for example, a high-frequency heating element 21 similar to that described in the embodiment of FIG. 2 is detachably attached to the anode 18 of the X-ray tube 13 and surrounds the cathode 17 of the X-ray tube 13. As described above, the tubular high-frequency heating element 4 similar to that described in the embodiment of FIG.
1 is arranged. A high-frequency coil 12 that is vertically wound is disposed outside the heat dissipation prevention tank 11.

According to this configuration, the anode is heated by the high-frequency heating element 21 attached to the anode 18.
In addition, the high-frequency heating element 41 disposed near the cathode 17 can heat the atmosphere in the heat dissipation prevention tank 11, thereby heating the vacuum vessel 16, the cathode 17, the anode 18, and the like. At this time, the heating temperature of the anode can be adjusted by changing the dimensions of the high-frequency heating element 21, and the heating temperature of the cathode 17 can be adjusted by adjusting the relative position between the high-frequency heating element and the cathode 17. Therefore, a good heating balance among the vacuum vessel 16, the cathode 17, and the anode 18 constituting the X-ray tube 13 can be obtained.

As described in the embodiment of FIGS. 4 and 5, when the vacuum vessel 16 constituting a part of the X-ray tube 13 is placed in the heat dissipation prevention tank 11 and heated, the heat dissipation prevention is performed. Tank 1
1 may be filled not with the atmosphere but with an inert gas. In this case, oxidation of the high-frequency heating element 41 can be prevented. When the inside of the heat dissipation preventing tank 11 is a pure inert gas atmosphere, graphite or the like can be used as the high-frequency heating element 41. In the above-described embodiment, iron or an iron-based alloy, nickel, or a nickel alloy is used as the high-frequency heating element. However, in the case of heating conditions, for example, conditions such as high temperature, W, Mo, T
a or their alloys can also be used.

In the above-described embodiment, an example in which heating is performed by a high-frequency heating element has been described. However, the temperature of the focus portion of the anode target where the electron beam is irradiated rises to about 2000 ° C. in the operating state. In such a case, by using both the heating by the high-frequency heating element and the heating by the irradiation of the electron beam, the anode target can be heated to a higher temperature, and more reliable exhaust can be performed.

Although the above embodiment has been described with reference to a fixed anode X-ray tube, the present invention can also be applied to a rotating anode X-ray tube in which the anode rotates.

[0051]

According to the present invention, it is possible to provide a stable X-ray tube having a small amount of residual gas, and a method and apparatus for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view illustrating another embodiment of the present invention.

FIG. 4 is a schematic sectional view showing another embodiment of the present invention.

FIG. 5 is a schematic sectional view showing another embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a conventional example.

FIG. 7 is a diagram illustrating a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Heat dissipation prevention tank 12 ... High frequency coil 13 ... X-ray tube 14 ... Exhaust pipe 15 ... Exhaust pump 16 ... Vacuum container 17 ... Cathode 18 ... Anode 19 ... Filament 20 ... Lead terminal 21 ... High frequency heating element

Claims (15)

[Claims] 1. A vacuum vessel constituting a part of an X-ray tube, a cathode disposed in the vacuum vessel for emitting an electron beam, and an anode target irradiated with the electron beam are provided in front and rearward. An X-ray tube comprising an anode located outside the vacuum vessel, wherein a high-frequency heating element made of a material different from the anode is provided on an outer peripheral portion of the anode. 2. The X-ray tube according to claim 1, wherein the high-frequency heating element has a thickness of 1 mm or less. 3. The X-ray tube according to claim 1, wherein the high-frequency heating element is provided on an outer peripheral portion of the anode by welding, brazing, or plating. 4. A step of fixing a cathode at one end in a vacuum vessel constituting a part of an X-ray tube, and fixing an anode having a high-frequency heating element provided on an outer peripheral portion to the other end of the vacuum vessel; An X-ray tube comprising: a step of disposing the vacuum vessel to which the cathode and the anode are fixed in a heat dissipation prevention tank; and a step of heating the high-frequency heating element provided on the outer peripheral portion of the anode with a high-frequency coil. Production method. 5. A step of fixing a cathode to one end of a vacuum vessel constituting a part of an X-ray tube and fixing an anode to the other end of the vacuum vessel, and the anode part located outside the vacuum vessel. X-rays comprising a step of attaching a high-frequency heating element to the anode part, a step of heating the high-frequency heating element attached to the anode part with a high-frequency coil, and a step of removing the high-frequency heating element attached to the anode part from the anode part. Pipe manufacturing method. 6. The method of manufacturing an X-ray tube according to claim 5, wherein the high-frequency heating element is formed in a rod shape having a diameter of 6 mm or less. 7. The method for manufacturing an X-ray tube according to claim 5, wherein the high-frequency heating element has a cylindrical portion having an outer diameter of 6 mm or more and a wall thickness of 1 mm or less. 8. An X-ray, comprising: a cylindrical high-frequency heating element surrounding a periphery of an X-ray tube in which a cathode and an anode are disposed inside a vacuum vessel; and a high-frequency coil for heating the high-frequency heating element. Pipe manufacturing equipment. 9. A method comprising: heating a cylindrical high-frequency heating element surrounding a periphery of an X-ray tube in which a cathode and an anode are arranged inside a vacuum vessel with a high-frequency coil; and irradiating the anode with an electron beam. Manufacturing method of wire tube. 10. A tubular high-frequency heating element in which a cathode or anode target surrounds an X-ray tube arranged inside a vacuum vessel;
A high-frequency heating element attached to the anode part located outside the vacuum vessel, and a high-frequency coil for heating the high-frequency heating element attached to the cylindrical high-frequency heating element and the anode part. X-ray tube manufacturing equipment. 11. The apparatus for manufacturing an X-ray tube according to claim 8, further comprising a heat dissipation prevention tank made of an electrically insulating material for accommodating the X-ray tube and the cylindrical high-frequency heating element. 12. A heat dissipation prevention tank made of an electric insulator for housing an X-ray tube and a cylindrical high-frequency heating element, wherein the inside of the heat dissipation prevention tank is an inert gas atmosphere. An apparatus for manufacturing an X-ray tube according to claim 10. 13. The method according to claim 4, wherein a step of irradiating the anode with an electron beam is provided.
Manufacturing method of wire tube. 14. The X-ray tube according to claim 8, wherein the tubular high-frequency heating element is arranged so as to surround the cathode-side end of the X-ray tube.
An apparatus for manufacturing an X-ray tube according to claim 10. 15. The high-frequency heating element is made of iron or an iron-based alloy, nickel or a nickel alloy, tungsten or a tungsten alloy, molybdenum or a molybdenum alloy, or tantalum or a tantalum alloy. The method or apparatus for manufacturing an X-ray tube or an X-ray tube according to any one of claims 4, 5, 8, 9, and 10.