JP2013149346A - X-ray tube device and x-ray ct device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray tube device in a structure capable of improving cooling efficiency by a simple structure and specially preventing overheat of a rotary bearing, and to provide an X-ray CT device loaded with the X-ray tube device.SOLUTION: The X-ray tube device includes a cathode for generating an electron beam, an anode for emitting X-rays by being irradiated with the electron beam, a package for holding the cathode and the anode in a vacuum atmosphere, and an anode rotary driving part for rotating the anode. The anode has a cylindrical shape part on a back side of a surface facing the cathode, and a vacuum cavity to be filled with an effector is provided inside the cylindrical shape part.

Description

  The present invention relates to an X-ray tube apparatus and an X-ray CT (Computed Tomography) apparatus.

  An X-ray CT device is an X-ray tube device that irradiates a subject with X-rays, and an X-ray detector that detects X-ray dose transmitted through the subject as projection data by rotating the subject around the subject. The tomographic image of the subject is reconstructed using the obtained projection data from a plurality of angles, and the reconstructed tomographic image is displayed. The image displayed by the X-ray CT apparatus describes the shape of an organ in the subject and is used for diagnostic imaging.

  In recent developments of X-ray CT apparatuses, the imaging time has been shortened by rotating a scanner equipped with an X-ray tube apparatus and an X-ray detector at a higher speed. In order to maintain the image quality of tomographic images even when the scanner rotates at high speed, it is necessary to increase the X-ray dose per unit time generated from the X-ray tube device. To increase the X-ray dose, the tube current must be increased and the amount of heat generated in the X-ray tube increases. The amount of heat generated in the X-ray tube has several adverse effects on the X-ray tube. For example, the cause of harmful effects such as melting of the X-ray target due to overheating of the anode, misalignment of the X-ray focal point due to thermal expansion of the rotating shaft of the anode, and rotation failure due to overheating of the solid lubricant used in the rotating bearing of the anode Become.

  Therefore, in order to prevent the harmful effects that can occur in the X-ray tube, various improvements have been made to the structure of the X-ray tube to improve the cooling efficiency. For example, in Patent Document 1, a vacuum cavity is formed inside the anode, and the cooling efficiency is improved by evaporating and condensing zinc, antimony, and bismuth, which are working fluid materials accommodated in the vacuum cavity. A tube apparatus is disclosed.

JP 2010-103046

  However, when the vacuum cavity for accommodating the working fluid material is formed inside the anode as in Patent Document 1, the working fluid material dissipates heat, so that the coolant flows inside the wall surface that the working fluid material radiates. It is necessary to form a path, and the X-ray tube apparatus has a complicated structure. Moreover, no consideration is given to preventing overheating of the rotary bearing.

  Therefore, an object of the present invention is to provide an X-ray tube apparatus having a structure that can improve cooling efficiency with a simple structure, and in particular, can prevent overheating of a rotary bearing, and an X-ray CT apparatus equipped with the X-ray tube apparatus. Is to provide.

  In order to achieve the above object, the present invention provides a vacuum cavity for filling the working body inside a cylindrical portion provided on the back surface of the cathode facing surface of the rotating anode, and the working body is disposed in the vacuum cavity. By evaporating and condensing, heat transfer from the rotary anode to the envelope is promoted.

  Specifically, a cathode that generates an electron beam, an anode that is disposed opposite to the cathode and emits X-rays when irradiated with the electron beam, and an envelope that holds the cathode and the anode in a vacuum atmosphere And an X-ray tube device comprising an anode rotation drive unit for rotating the anode, the anode having a cylindrical part on the back side of the surface facing the cathode, The X-ray tube apparatus is characterized in that a vacuum cavity portion filled with an operating body is provided inside.

  In addition, the X-ray tube device, the X-ray detector that is disposed opposite to the X-ray tube device and detects X-rays transmitted through the subject, the X-ray tube device and the X-ray detector are mounted, and the target is mounted. A rotating disk that rotates around the specimen, an image reconstruction device that reconstructs a tomographic image of the subject based on transmitted X-ray doses from a plurality of angles detected by the X-ray detector, and the image reconstruction device. An X-ray CT apparatus comprising: an image display device that displays a reconstructed tomographic image.

  According to the present invention, an X-ray tube apparatus capable of improving cooling efficiency with a simple structure and preventing overheating of a rotary bearing, and an X-ray CT apparatus equipped with the X-ray tube apparatus are provided. Can do.

The block diagram which shows the whole structure of the X-ray CT apparatus of this invention The figure which shows the whole structure of the X-ray tube apparatus of this invention The figure which shows the structure of the anode periphery of 1st embodiment. The figure which shows the flow of the heat transfer around the anode of 1st embodiment The figure which shows the structure of the anode periphery of 2nd embodiment. The figure which shows the structure of the anode periphery of 3rd embodiment. The figure which shows the structure of the anode periphery of 4th embodiment. The figure which shows the structure of the anode periphery of 5th embodiment.

  Hereinafter, preferred embodiments of an X-ray CT apparatus according to the present invention will be described with reference to the accompanying drawings. In the following description and the accompanying drawings, the same reference numerals are given to the constituent elements having the same functional configuration, and redundant description will be omitted.

  The overall configuration of the X-ray CT apparatus 1 to which the present invention is applied will be described with reference to FIG. The X-ray CT apparatus 1 includes a scan gantry unit 100 and a console 120.

  The scan gantry unit 100 includes an X-ray tube device 101, a rotating disk 102, a collimator 103, an X-ray detector 106, a data collection device 107, a bed 105, a gantry control device 108, and a bed control device 109. An X-ray control device 110. The X-ray tube device 101 is a device that irradiates a subject placed on a bed 105 with X-rays. The collimator 103 is a device that limits the radiation range of X-rays emitted from the X-ray tube device 101. The rotating disk 102 includes an opening 104 into which the subject placed on the bed 105 enters, and is equipped with an X-ray tube device 101 and an X-ray detector 106, and rotates around the subject. The X-ray detector 106 is a device that measures the spatial distribution of transmitted X-rays by detecting X-rays that are disposed opposite to the X-ray tube device 101 and transmitted through the subject. The rotating disk 102 is arranged in the rotating direction, or the rotating disk 102 is arranged two-dimensionally in the rotating direction and the rotating shaft direction. The data collection device 107 is a device that collects the X-ray dose detected by the X-ray detector 106 as digital data. The gantry control device 108 is a device that controls the rotation of the rotary disk 102. The bed control device 109 is a device that controls the vertical and horizontal movements of the bed 105. The X-ray control device 110 is a device that controls electric power input to the X-ray tube device 101.

  The console 120 includes an input device 121, an image arithmetic device 122, a display device 125, a storage device 123, and a system control device 124. The input device 121 is a device for inputting a subject's name, examination date and time, imaging conditions, and the like, specifically a keyboard or a pointing device. The image computation device 122 is a device that performs CT processing on the measurement data sent from the data collection device 107 and performs CT image reconstruction. The display device 125 is a device that displays the CT image created by the image calculation device 122, and is specifically a CRT (Cathode-Ray Tube), a liquid crystal display, or the like. The storage device 123 is a device that stores data collected by the data collection device 107 and image data of a CT image created by the image calculation device 122, and is specifically an HDD (Hard Disk Drive) or the like. The system control device 124 is a device that controls these devices, the gantry control device 108, the bed control device 109, and the X-ray control device 110.

  The X-ray tube device 101 is controlled by the X-ray controller 110 controlling the power input to the X-ray tube device 101 based on the imaging conditions input from the input device 121, in particular, the X-ray tube voltage and the X-ray tube current. Irradiates the subject with X-rays according to imaging conditions. The X-ray detector 106 detects X-rays irradiated from the X-ray tube apparatus 101 and transmitted through the subject with a large number of X-ray detection elements, and measures the distribution of transmitted X-rays. The rotating disk 102 is controlled by the gantry control device 108, and rotates based on the photographing conditions input from the input device 121, particularly the rotation speed. The couch 105 is controlled by the couch controller 109 and operates based on the photographing conditions input from the input device 121, particularly the helical pitch.

  By repeating the X-ray irradiation from the X-ray tube device 101 and the measurement of the transmitted X-ray distribution by the X-ray detector 106 along with the rotation of the rotating disk 102, projection data from various angles is acquired. The acquired projection data from various angles is transmitted to the image calculation device 122. The image calculation device 122 reconstructs the CT image by performing back projection processing on the transmitted projection data from various angles. The CT image obtained by the reconstruction is displayed on the display device 125.

  Depending on the size of the opening 104 of the rotating disk 102 and the thickness of the scan gantry unit 100, the subject may feel a sense of pressure. Therefore, it is desirable that the opening 104 is large and the scan gantry unit 100 is thin. Since the size of the opening 104 and the thickness of the scan gantry unit 100 depend on the size of the load on the rotating disk 102, it is preferable that the X-ray tube device 101, which is one of the loads, is smaller. .

  The configuration of the X-ray tube apparatus 101 will be described with reference to FIG. The X-ray tube apparatus 101 includes an X-ray tube 210 that generates X-rays and a container 220 that stores the X-ray tube 210.

  The X-ray tube 210 includes a cathode 211 that generates an electron beam, an anode 212 to which a positive potential is applied to the cathode 211, and an envelope 213 that holds the cathode 211 and the anode 212 in a vacuum atmosphere.

  The cathode 211 includes a filament or a cold cathode and a focusing electrode. The filament is formed by winding a high melting point material such as tungsten in a coil shape, and is heated when a current is passed to emit thermoelectrons. A cold cathode is formed by sharpening a metal material such as nickel or molybdenum, and emits electrons by field emission when an electric field is concentrated on the cathode surface. The focusing electrode forms a focusing electric field for focusing the emitted electrons toward the X-ray focal point on the anode 212. The filament or cold cathode and the focusing electrode are at the same potential.

  The anode 212 includes a target and an anode base material. The target is made of a material having a high melting point and a large atomic number, such as tungsten. X-rays 217 are emitted from the X-ray focal point when electrons emitted from the cathode 211 collide with the X-ray focal point on the target. The anode base material holds the target and is made of a material having high thermal conductivity such as copper. The target and the anode base material are at the same potential.

  The envelope 213 maintains the cathode 211 and the anode 212 in a vacuum atmosphere in order to electrically insulate the cathode 211 and the anode 212 from each other. The envelope 213 is provided with a radiation window 218 for emitting X-rays 217 to the outside of the X-ray tube 210. The radiation window 218 is made of a material having a small atomic number such as beryllium having a high X-ray transmittance. The radiation window 218 is also provided in the container 220 described later. The potential of the envelope 213 is a ground potential.

  The electrons emitted from the cathode 211 are accelerated by a voltage applied between the cathode and the anode and become an electron beam 216. When the electron beam 216 is focused by the focusing electric field and collides with the X-ray focal point on the target, X-rays 217 are generated from the X-ray focal point. The energy of the generated X-ray is determined by the voltage applied between the cathode and the anode, so-called tube voltage. The dose of X-rays generated depends on the amount of electrons emitted from the cathode, the so-called tube current and the tube voltage.

  Of the energy of the electron beam 216, the ratio of being converted to X-rays is only about 1%, and most of the remaining energy is heat. In the X-ray tube apparatus 101 mounted on the medical X-ray CT apparatus 1, the tube voltage is hundreds of kV and the tube current is several hundred mA, so the anode 212 is heated with a heat quantity of several tens kW. In order to prevent the anode 212 from being overheated and melted by such heating, the anode 212 is connected to the rotating body support mechanism 215, and the one-dot chain line 219 in FIG. Rotates as an axis. The rotating body support mechanism 215 drives the magnetic field generated by the excitation coil 214 as a rotational driving force. By rotating the anode 212, the X-ray focal point where the electron beam 216 collides always moves, so that the temperature of the X-ray focal point can be kept lower than the melting point of the target, and the anode 212 can be overheated and melted. Can be prevented.

  The X-ray tube 210 and the excitation coil 214 are accommodated in the container 220. The container 220 is filled with cooling water as a cooling medium or an insulating oil as a cooling medium while electrically insulating the X-ray tube 210. Cooling water or insulating oil filled in the container 220 is guided to the cooler through a pipe connected to the container 220 of the X-ray tube device 101, and after the heat is dissipated in the cooler, the heat is dissipated in the container 220 through the pipe. Returned.

  The anode 212 has an average temperature of about 1000 ° C. due to heat generated at the X-ray focal point. Most of the generated heat is radiated from the surface of the anode 212 to the envelope 213 by radiation, and the remaining heat flows to the envelope 213 through the rotating body support mechanism 215 by heat conduction. Since the heat flowing to the rotating body support mechanism 215 causes various harmful effects, it is necessary to devise a method of heat transfer. Hereinafter, the structure around the anode 212, particularly the rotating body support mechanism 215 connected to the anode 212 will be described in detail.

(First embodiment)
FIG. 3 is a view showing a structure around the anode 212 of the first embodiment. The rotating body support mechanism 215 is connected to the back side of the surface where the anode 212 faces the cathode 211, and includes a fixed portion 215A, a rotating bearing 215B, a rotating shaft portion 215C, and a rotating cylindrical portion 215D.

  The fixed portion 215A has a cylindrical shape, and one end is supported by the envelope 213. A rotary bearing 215B is held on the inner surface of the cylinder.

  The rotary bearing 215B supports the rotary shaft portion 215C in a rotatable manner, and is, for example, a ball bearing, a slide bearing, a fluid bearing, or the like. When a large amount of heat flows through the rotary bearing 215B, the rotational performance deteriorates due to the thermal expansion of the rotary bearing 215B or the phase change of the lubricant, and in the worst case, the rotation becomes impossible, so the amount of heat transfer to the rotary bearing 215B is suppressed. It is preferred that

  The rotation shaft portion 215C has a cylindrical shape and is disposed inside the fixed portion 215A. A rotating cylindrical portion 215D is connected to the rotating shaft portion 215C, and an anode 212 is connected to the rotating cylindrical portion 215D. A metal having a low thermal conductivity, such as stainless steel, may be interposed between the rotating cylindrical portion 215D and the rotating shaft portion 215C in order to suppress the amount of heat transfer.

  The rotating cylindrical portion 215D has a cylindrical shape, and a fixed portion 215A and a rotating shaft portion 215C are disposed inside the rotating cylindrical portion 215D. The outer peripheral surface of the rotating cylindrical portion 215D faces the inner surface of the envelope 213.

  The rotating cylindrical portion 215D rotates around the alternate long and short dash line 219 by receiving the magnetic field generated by the exciting coil 214. Along with the rotation of the rotating cylindrical portion 215D, the anode 212 and the rotating shaft portion 215C connected to the rotating cylindrical portion 215D also rotate around the alternate long and short dash line 219. In the following description, the rotation axis of the anode 212 is referred to as a rotation axis 219 using the reference numeral 219.

  In this embodiment, in order to suppress the amount of heat transferred from the anode 212 to the rotary body support mechanism 215 to the rotary bearing 215B, a vacuum cavity 300 is provided inside the rotary cylinder 215D. Fill with liquid. The amount of heat transferred to the rotary bearing 215B is suppressed by the latent heat when the liquid filled in the vacuum cavity 300 changes to gas, that is, when it evaporates.

  The vacuum cavity 300 may have any shape that extends in the direction of the rotating shaft 219 from the position where the rotating cylindrical portion 215D and the rotating shaft portion 215C are connected. For example, the vacuum hollow portion 300 may have a thin cylindrical shape, A plurality of cylinders arranged in the circumferential direction may be used.

For example, pure water is used as the liquid filled in the vacuum cavity 300. The latent heat of pure water is 2258 J / cm ^3, which is sufficiently larger than the sensible heat 400 J / cm ³ for raising the temperature of pure iron by 100 K, and the amount of heat transfer to the rotary bearing 215B can be sufficiently suppressed.

  In order to fill the vacuum cavity 300 with the liquid, the inside of the vacuum cavity 300 is evacuated and then filled with the liquid, and the vacuum cavity 300 is sealed. Moreover, the same method as that for producing a known heat pipe may be used. Further, separately from the rotating cylindrical portion 215D, a cylindrical portion having a vacuum cavity portion 300 filled with a liquid may be created and disposed outside or inside the rotating cylindrical portion 215D.

  Further, the vacuum cavity 300 may be filled with a solid material having a melting point lower than that of the surrounding material. The heat of fusion when the material having a low melting point undergoes a phase change by heat and becomes a liquid is also a kind of latent heat, and a large amount of energy is consumed as compared with the sensible heat of the surrounding material.

  The inner surface of the vacuum cavity 300 may be coated with a material having a low affinity with the liquid or solid material filled in the vacuum cavity 300. By coating the inner surface of the vacuum cavity 300 with a material having low affinity, the liquid or solid material can move smoothly in the vacuum cavity 300. Note that the liquid and the solid material filled in the vacuum cavity 300 are collectively referred to as an operating body.

  The heat flow around the anode 212 to which the rotating body support mechanism 215 described in FIG. 3 is connected will be described with reference to FIG. Since the rotating body support mechanism 215 and the anode 212 have a rotationally symmetric structure with respect to the rotating shaft 219, only half of them are shown in FIG. In FIG. 4, the flow of heat transfer from the anode 212 to the rotating body support mechanism 215 is indicated by an arrow, and the thickness of the arrow is changed according to the amount of heat transferred. In addition, the thickness of the arrow is only what shows the amount of heat transfer typically.

  The heat generated at the anode 212 is transferred to the rotating cylindrical portion 215D by heat conduction. Most of the heat transferred to the rotating cylinder 215D is evaporated into the vacuum cavity 300 in the vicinity of the position where the rotating cylinder 215D and the rotating shaft 215C are connected to evaporate the liquid in the vacuum cavity 300. Heat is transferred, and the remaining amount of heat is transferred to the rotating shaft 215C by heat conduction. The liquid or vapor evaporated in the vacuum cavity 300 moves to a low temperature part in the vacuum cavity 300, for example, the end farthest from the anode 212 of the vacuum cavity 300, and dissipates heat by condensing. The amount of heat dissipated in the low temperature part in the vacuum cavity 300 is transferred to the surface of the rotating cylindrical part 215D by heat conduction, and further radiated to the envelope 213 and the fixing part 215A facing the surface of the rotating cylindrical part 215D. Heat transfer. The amount of heat transferred to the envelope 213 and the fixed portion 215A is transferred by heat transfer to the cooling water or insulating oil filled between the envelope 213 and the container 220.

  The liquid condensed in the vacuum cavity 300 circulates to a position where the rotary cylinder 215D and the rotary shaft 215C, which are high-temperature parts, are connected, and is evaporated again to transfer heat to the rotary cylinder 215D. Most of the heat is transferred into the vacuum cavity 300. Further, the amount of heat transferred to the rotating shaft portion 215C is transferred to the fixed portion 215A via the rotating bearing 215B by heat conduction.

  As described above, according to the configuration of the present embodiment, most of the heat generated from the anode 212 to the rotating body support mechanism 215 is transferred to the cooling water or insulating oil filled in the container 220 via the vacuum cavity 300. Since heat is transferred, the amount of heat transferred to the rotary bearing 215B can be significantly reduced. As a result, overheating of the rotary bearing can be prevented. The X-ray tube apparatus 101 can also have a simple structure because it is only necessary to provide the vacuum cavity 300 for filling the inside of the rotary cylindrical portion 215D.

(Second embodiment)
FIG. 5 is a view showing the structure around the anode 212 of the second embodiment. A significant difference from the first embodiment is the form of the vacuum cavity 300. Each configuration will be described below. In addition, about the same structure as 1st embodiment, it is the same code | symbol and abbreviate | omits description.

  In the present embodiment, the vacuum cavity 300 has an inclination with respect to the rotation shaft 219, and the end closer to the anode is farther away from the rotation shaft 219 than the far end. By adopting such a configuration, the liquid condensed in the vacuum cavity 300 can be smoothly moved to a position where the rotary cylinder 215D and the rotary shaft 215C, which are high temperature parts, are connected. The reason will be described below.

  Liquid and gas have different densities, and liquid is heavier. Therefore, by forming the vacuum cavity portion 300 as shown in FIG. 5, the liquid can be moved away from the rotation shaft 219 by the centrifugal force generated by the rotation of the rotating cylindrical portion 215D. As a result, the condensed liquid can move smoothly to the high temperature part, and conversely, the vapor moves to the low temperature part, so heat transfer from the high temperature part to the low temperature part is promoted, and the cooling efficiency can be improved.

(Third embodiment)
FIG. 6 is a view showing a structure around the anode 212 of the third embodiment. A significant difference from the first and second embodiments is the surface of the rotating cylindrical portion 215D. Each configuration will be described below. In addition, about the same structure as 1st, 2nd embodiment, it is set as the same code | symbol and description is abbreviate | omitted.

  In the present embodiment, the radiation film 600 is formed to face the outer surface of the rotating cylindrical portion 215D and the inner surface of the envelope 213. The radiation film 600 is a film for improving the radiation rate of heat from the surface, and is a black film formed by plating, vacuum deposition, ion plating, sputtering film formation, or the like. It is desirable to form the radiation film 600 with a material having a heat resistance of about several hundred degrees and a higher emissivity than the rotating cylindrical portion 215D. By forming the radiation film 600 on the outer surface of the rotating cylindrical portion 215D and the inner surface of the envelope 213, heat transfer by radiation from the rotating cylindrical portion 215D to the envelope 213 can be further improved.

  FIG. 6 shows an example in which the radiation film 600 is formed on the outer surface of the rotating cylindrical portion 215D and the inner surface of the envelope 213, but it is also possible to form the radiation film 600 only on one of the surfaces. good.

  Further, the radiation film 600 may be formed on at least one of the inner surface of the rotating cylindrical portion 215D and the outer surface of the fixed portion 215A. By forming the radiation film 600 on at least one of the inner surface of the rotating cylindrical portion 215D and the outer surface of the fixed portion 215A, heat transfer by radiation from the rotating cylindrical portion 215D to the fixed portion 215A can be further improved. .

(Fourth embodiment)
FIG. 7 is a view showing the structure around the anode 212 of the fourth embodiment. A significant difference from the first and second embodiments is the surface of the rotating cylindrical portion 215D. Each configuration will be described below. In addition, about the same structure as 1st, 2nd embodiment, it is set as the same code | symbol and description is abbreviate | omitted.

  In the present embodiment, the fin 700 is formed on the inner surface of the rotating cylindrical portion 215D. By forming the fin 700 on the inner surface of the rotating cylindrical portion 215D, heat transfer by radiation from the rotating cylindrical portion 215D to the fixed portion 215A can be further improved.

(Fifth embodiment)
FIG. 8 is a view showing the structure around the anode 212 of the fifth embodiment. A significant difference from the first and second embodiments is the form of the rotating cylindrical portion 215D and the envelope 213. Each configuration will be described below. In addition, about the same structure as 1st, 2nd embodiment, it is set as the same code | symbol and description is abbreviate | omitted.

  In the present embodiment, the length of the rotating cylindrical portion 215D in the direction of the rotating shaft 219 is made longer than that of the fixed portion 215A, and the length of the vacuum cavity portion 300 is also extended in the direction of the rotating shaft 219 so as to be inside the rotating cylindrical portion 215D. The envelope 213 protrudes. By adopting such a configuration, the area where the rotating cylindrical portion 215D and the envelope 213 face each other is increased, and heat transfer to the cooling water or insulating oil circulating on the outer surface of the envelope 213 is promoted. The As a result, heat transfer by radiation from the rotating cylindrical portion 215D to the envelope 213 can be further improved.

  Although a plurality of embodiments have been described above, the present invention is not limited to the above embodiments. For example, in the above embodiment, the rotating anode has been described, but the present invention can also be applied to a fixed anode. That is, you may provide a vacuum cavity part in the base material of a fixed anode.

  Moreover, you may combine several embodiment suitably. For example, a radiation film may be formed on the surface of the fin by a combination of the third embodiment and the fourth embodiment. Further, the fifth embodiment may be combined with the third embodiment or the fourth embodiment.

  1 X-ray CT device, 100 scan gantry unit, 101 X-ray tube device, 102 rotating disk, 103 collimator, 104 opening, 105 bed, 106 X-ray detector, 107 data collection device, 108 gantry control device, 109 bed control Device, 110 X-ray control device, 120 console, 121 input device, 122 image processing device, 123 storage device, 124 system control device, 125 display device, 210 X-ray tube, 211 cathode, 212 anode, 213 envelope, 214 Excitation coil, 215 Rotating body support, 215A fixed part, 215B Rotating bearing, 215C Rotating shaft part, 215D Rotating cylindrical part, 216 Electron beam, 217 X-ray, 218 Radiation window, 219 Rotating shaft, 220 Container, 300 Vacuum cavity Part, 600 radiation film, 700 fins

Claims (6)

A cathode that generates an electron beam; an anode that is disposed opposite to the cathode and emits X-rays when irradiated with the electron beam; an envelope that holds the cathode and the anode in a vacuum atmosphere; and the anode An X-ray tube apparatus having an anode rotation drive unit for rotating
The anode has a cylindrical portion on the back side of the surface facing the cathode,
An X-ray tube apparatus characterized in that a vacuum cavity portion filled with an operating body is provided inside the cylindrical portion. The X-ray tube apparatus according to claim 1,
The X-ray tube apparatus characterized in that the vacuum cavity portion has an inclination in the rotation axis direction of the anode, and an end portion close to the anode is further away from a rotation axis of the anode than a far end portion. . The X-ray tube apparatus according to claim 1 or 2,
An X-ray tube apparatus, wherein a radiation film is formed on a surface of the cylindrical portion. The X-ray tube apparatus according to claim 1 or 2,
An X-ray tube apparatus, wherein a fin is formed on a surface of the cylindrical portion. In the X-ray tube device according to any one of claims 1 to 4,
The X-ray tube apparatus, wherein the envelope protrudes inside the cylindrical portion. Equipped with an X-ray source for irradiating a subject with X-rays, an X-ray detector arranged to face the X-ray source and detecting X-rays transmitted through the subject, and the X-ray source and the X-ray detector A rotating disk rotating around the subject, an image reconstruction device for reconstructing a tomographic image of the subject based on the transmitted X-ray dose detected by the X-ray detector, and reconstruction by the image reconstruction device An X-ray CT apparatus comprising: an image display device that displays the tomographic image obtained
The X-ray CT apparatus according to claim 1, wherein the X-ray source is the X-ray tube apparatus according to claim 1.

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