X-ray tube apparatus, x-ray apparatus, and treatment method for x-ray tube apparatus

Abstract

To provide an X-ray tube apparatus capable of restoring the amount of electrons emitted from a cathode, an X-ray apparatus, and a treatment method for the X-ray tube apparatus.SOLUTION: The X-ray tube apparatus includes an electron source capable of emitting electrons when a voltage is applied, a focusing electrode surrounding the electron source, an anode capable of generating X-rays when the electrons emitted from the electron source are incident thereon, a cathode power supply capable of applying the voltage to the electron source, and a power supply capable of applying a first positive voltage to the focusing electrode.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to an X-ray tube device, an X-ray device, and a treatment method for an X-ray tube device.

Background Art

[0002] An X-ray tube device includes, for example, an outer container capable of maintaining an atmosphere depressurized from atmospheric pressure, a cathode provided inside the outer container, and a target provided inside the outer container at a position facing the cathode. Further, the cathode includes, for example, a filament that emits electrons and a cylindrical focusing electrode that surrounds the filament.

[0003] Here, the amount of electrons emitted from the cathode may decrease over time. The reason for the decrease in the amount of emitted electrons is not necessarily clear, but it is conceivable that residual gas or the like inside the outer container becomes positive ions and adheres to the surfaces of the focusing electrode and the filament at a negative potential.

[0004] When the amount of electrons emitted from the cathode decreases, the dose of X-rays emitted from the X-ray tube device decreases. For example, the quality of an X-ray image may deteriorate, or the accuracy of measuring or inspecting the thickness of an object may decrease.

[0005] Therefore, the development of a technology capable of restoring the amount of electrons emitted from the cathode has been desired.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved by the present invention is to provide an X-ray tube device, an X-ray device, and a treatment method for an X-ray tube device that can restore the amount of electrons emitted from a cathode.

Means for Solving the Problem

[0008] The X-ray tube device according to the embodiment includes an electron source capable of emitting electrons when a voltage is applied, a focusing electrode surrounding the electron source, an anode capable of generating X-rays when the electrons emitted from the electron source are incident thereon, a cathode power source capable of applying the voltage to the electron source, and a power source capable of applying a positive first voltage to the focusing electrode.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments will be exemplified with reference to the drawings. In each drawing, the same reference numerals are given to the same components, and detailed descriptions thereof are omitted as appropriate.

[0011] (X-ray tube device) FIG. 1 is a block diagram for exemplifying the X-ray tube device 1 according to the present embodiment. As shown in FIG. 1, the X-ray tube device 1 is provided with, for example, an X-ray tube 10, a cathode power source 20, a high-voltage power source 30, a power source 40, and a controller 50.

[0012] The X-ray tube 10 includes, for example, an envelope 11, a cathode 12, and an anode 13. The outer enclosure 11 is capable of maintaining an atmosphere (also referred to as a vacuum state) that is depressurized relative to atmospheric pressure. The outer enclosure 11 has a cylindrical shape. The outer enclosure 11 has, for example, a shape extending in one direction (e.g., cylindrical). The outer enclosure 11 is formed using a glass material such as borosilicate glass.

[0013] The cathode 12 is provided inside the outer enclosure 11. The cathode 12 is sealed, for example, at one end of the outer enclosure 11. The cathode 12 has, for example, a filament 12a and a focusing electrode (Wehnelt electrode) 12b.

[0014] The filament 12a is electrically connected to the cathode power supply 20. The filament 12a has a coiled shape in which a linear material is wound. The material of the linear material is, for example, tungsten.

[0015] Although the cathode 12 provided with the filament 12a has been illustrated, instead of the filament 12a, a heater and a plate-shaped impregnated cathode structure heated by the heater may be provided. The heater is not particularly limited as long as it generates heat when energized. The impregnated cathode structure has, for example, a plate-shaped body formed using porous tungsten or the like, and an electron-emitting substance (also referred to as an emitter) held in the pores of the plate-shaped body. The electron-emitting substance is, for example, barium oxide (BaO), calcium oxide (CaO), aluminum oxide (Al2O3), or the like. That is, the cathode 12 may be provided with an electron source that emits electrons when a voltage is applied thereto.

[0016] The focusing electrode 12b surrounds the electron source (e.g., the filament 12a). The focusing electrode 12b has, for example, a cylindrical shape with openings at both ends. The focusing electrode 12b can be formed from a conductive material such as iron (Fe) or stainless steel.

[0017] The focusing electrode 12b converges, for example, the electrons emitted from the electron source and forms a focus on the target layer 13a1 of the target 13a described later. Therefore, generally, the focusing electrode 12b is connected to the same potential as the filament 12a or a negative voltage is applied thereto in order to converge the electrons.

[0018] The anode 13 is provided inside the envelope 11. The anode 13 is sealed, for example, at the other end of the envelope 11. The anode 13 has a target 13a, a rotating part 13b, and a stator 13c.

[0019] The target 13a has, for example, a disc shape. The peripheral region of the surface of the target 13a on the cathode 12 side is an inclined surface. The inclined surface of the target 13a faces the filament 12a. The target 13a can be formed from, for example, a molybdenum alloy or the like. A target layer 13a1 can be provided on the inclined surface of the target 13a. The target layer 13a1 can be formed from, for example, a tungsten alloy. Note that the target 13a can be formed from, for example, a tungsten alloy and the target layer 13a1 can be omitted.

[0020] The rotating part 13b extends inside the envelope 11. The target 13a is provided at the end of the rotating part 13b on the cathode 12 side. A fixed shaft 13b1 is provided inside the rotating part 13b. The rotating part 13b is rotatably supported by the fixed shaft 13b1 via a sliding bearing or the like. The fixed shaft 13b1 can be provided substantially coaxially with the central axis of the envelope 11. One end of the fixed shaft 13b1 is provided at the end of the envelope 11. For example, the fixed shaft 13b1 extends inside the envelope 11 and one end is exposed outside the envelope 11. The rotating part 13b and the fixed shaft 13b1 can be formed from a metal such as iron or a molybdenum alloy.

[0021] The stator 13c is provided outside the outer casing 11. The stator 13c is formed, for example, by winding a wire. When an electric current flows through the stator 13c, a magnetic field is generated, and the rotating part 13b rotates due to the generated magnetic field. Therefore, the position of the target 13a (target layer 13a1) can be moved in the rotational direction.

[0022] That is, the X-ray tube 10 illustrated in FIG. 1 is a rotating anode X-ray tube. However, the X-ray tube 10 is not necessarily limited to a rotating anode X-ray tube. The X-ray tube 10 may be a stationary anode X-ray tube. When the X-ray tube 10 is a stationary anode X-ray tube, for example, a columnar support that extends inside the outer casing 11 and has an end on the cathode 12 side inclined with respect to the central axis of the outer casing 11, and a target provided at the inclined end of the support may be provided. The rotating anode or the stationary anode generates X-rays when electrons emitted from an electron source are incident thereon.

[0023] The cathode power supply 20 is electrically connected to the filament 12a. When an impregnated cathode structure and a heater are provided instead of the filament 12a, the cathode power supply 20 is electrically connected to the heater. The cathode power supply 20 applies a voltage to an electron source (for example, the filament 12a or the heater). The voltage applied to the electron source is, for example, about 2V to 20V.

[0024] For example, when a voltage is applied to the filament 12a by the cathode power supply 20, the filament 12a is heated and electrons (thermoelectrons) are emitted from the filament 12a. When an impregnated cathode structure and a heater are provided, when a voltage is applied to the heater by the cathode power supply 20, the impregnated cathode structure is heated and electrons are emitted from the electron-emitting substance held in the impregnated cathode structure.

[0025] The high-voltage power supply 30 is electrically connected to the anode 13 and the filament 12a. For example, the high-voltage power supply 30 is electrically connected to the fixed shaft 13b1 of the anode 13. When a fixed anode is provided instead of a rotating anode, the high-voltage power supply 30 is electrically connected to a columnar support. The high-voltage power supply 30 applies a high voltage between the anode 13 and the cathode power supply 20. The voltage applied is, for example, about 20 kV to 200 kV.

[0026] The electrons emitted from the cathode 12 are accelerated by the positive voltage applied to the anode 13 and collide with the target 13a (target layer 13a1). When the accelerated electrons collide with the target 13a (target layer 13a1), X-rays are generated, and the generated X-rays are radiated to the outside of the outer vessel 11.

[0027] Also, as described above, generally, in order to converge electrons on the target 13a (target layer 13a1), the focusing electrode 12b is connected to the same potential as the filament 12a, or a negative voltage is applied to the focusing electrode 12b. For example, a bias voltage of -5 kV to 0 V (superimposed voltage based on the filament voltage) is applied to the focusing electrode 12b.

[0028] Here, the amount of electrons emitted from the cathode 12 may decrease over time. When the amount of electrons emitted from the cathode 12 decreases, the dose of X-rays radiated from the X-ray tube device 1 will decrease. When the dose of X-rays decreases, for example, the quality of the X-ray image may deteriorate, or the accuracy of measuring or inspecting the thickness of an object may decrease.

[0029] Although the reason for the decrease in the amount of electrons emitted from the cathode 12 over time is not necessarily clear, it is conceivable that residual gas or the like inside the envelope 11 becomes positive ions and adheres to the surfaces of the focusing electrode 12b and the filament 12a at a negative potential. In this case, when there is a certain amount of deposits on the surface of the focusing electrode 12b or the like, the deposits are decomposed by the heat from the filament 12a or the like, generating gas. When gas is generated, the degree of vacuum deteriorates in the vicinity of the cathode 12, making it easier to prevent the emission of electrons. It is considered that the amount of electrons emitted decreases over time as described above.

[0030] Therefore, the X-ray tube device 1 is provided with a power supply 40. The power supply 40 is provided to recover the amount of electrons emitted from the cathode 12. In the following, the case of the cathode 12 having the filament 12a will be described, but the same applies to the case of a cathode having a heater and an impregnated cathode structure.

[0031] FIG. 2 is a block diagram for exemplifying the operation of the power supply 40. As shown in FIG. 2, the power supply 40 is electrically connected to the focusing electrode 12b. The power supply 40 applies a positive voltage (corresponding to an example of the first voltage) to the focusing electrode 12b. In this case, the power supply 40 applies a positive voltage to the focusing electrode 12b when the amount of electrons emitted from the cathode 12 becomes lower than a predetermined value.

[0032] The decrease in the amount of electrons emitted from the cathode 12 can be detected, for example, by a decrease in at least either the tube current or the tube voltage. For example, the power supply 40 applies a positive voltage to the focusing electrode 12b when the tube current or the tube voltage drops by about 20% to 30% from the rated value. The tube current and the tube voltage can be detected, for example, by a detection unit 30a (corresponding to an example of the first detection unit) provided between the high-voltage power supply 30 and the anode 13 as shown in FIG. 1. The detection unit 30a can be, for example, at least either an ammeter or a voltmeter. Note that a positive voltage may be applied to the focusing electrode 12b from the power supply 40 periodically or as necessary.

[0033] As described above, when a voltage is applied to the filament 12a by the cathode power supply 20, electrons are emitted from the filament 12a. As shown in FIG. 2, when a positive voltage is applied to the focusing electrode 12b by the power supply 40, the emitted electrons are drawn into the focusing electrode 12b. When electrons enter the focusing electrode 12b, a current flows through the focusing electrode 12b, so the focusing electrode 12b generates heat. If the temperature of the focusing electrode 12b increases, the deposits on the surface of the focusing electrode 12b can be decomposed by heat.

[0034] Also, the following effects may occur. There is residual gas inside the envelope 11. Also, deposits adhering to the focusing electrode 12b may be decomposed to generate gas. When electrons collide with gas molecules in the vicinity of the focusing electrode 12b, the gas molecules are ionized. When the ionized gas molecules collide with deposits on the surfaces of the filament 12a and the focusing electrode 12b, the deposits are sputtered.

[0035] Therefore, if a positive voltage is applied to the focusing electrode 12b by the power supply 40, the deposits adhering to at least either the focusing electrode 12b or the filament 12a can be removed.

[0036] When applying a voltage by the power supply 40, the voltage application by the high-voltage power supply 30 described above is not performed. If the voltage application by the high-voltage power supply 30 is not performed, it is possible to suppress the electrons emitted from the cathode 12 from being drawn to the anode 13 side. Therefore, it is possible to suppress the unintentional emission of X-rays while the electron amount is being restored by the power supply 40.

[0037] FIGS. 3(a) to (c) are graphs for exemplifying the effect of voltage application by the power supply 40. When removing the deposits by the power supply 40, as shown in Fig. 3(b), a current (filament current) is passed through the filament 12a by the cathode power supply 20. The current flowing through the filament 12a is, for example, about 4 A. When a current flows through the filament 12a, electrons are emitted from the filament 12a as described above (see Fig. 2).

[0038] Also, as shown in Fig. 3(a), a positive voltage is applied to the focusing electrode 12b by the power supply 40. The voltage applied to the focusing electrode 12b is about 50 V to 500 V. When a positive voltage is applied to the focusing electrode 12b, as described above, the electrons emitted from the filament 12a are drawn into the focusing electrode 12b and a current flows through the focusing electrode 12b (see Fig. 2). Therefore, the temperature of the focusing electrode 12b rises and the deposits on the surface of the focusing electrode 12b are decomposed by heat.

[0039] Also, if the voltage applied to the focusing electrode 12b is about 50 V to 500 V, the above-described sputtering is likely to occur. For example, it is considered that the deposits can be physically removed by causing the ionized gas molecules to collide with the deposits on the surfaces of the filament 12a and the focusing electrode 12b.

[0040] If the deposits on the surfaces of the filament 12a and the focusing electrode 12b are removed, the amount of electrons emitted from the cathode 12 can be restored. The restoration of the amount of electrons emitted from the cathode 12 can be detected, for example, by the current flowing through the focusing electrode 12b as shown in Fig. 3(c). According to the findings obtained by the present inventor, as shown in Fig. 3(c), the current that had dropped to 80 mA could be restored to 100 mA in about 5 minutes from the start of the application of the voltage by the power supply 40.

[0041] The current flowing through the focusing electrode 12b can be detected by an ammeter provided between the power supply 40 and the focusing electrode 12b. Alternatively, a voltmeter may be provided between the power supply 40 and the focusing electrode 12b, and the recovery timing may be detected based on the change in voltage. That is, as shown in FIG. 2, a detection unit 40a (corresponding to an example of a second detection unit) capable of detecting at least one of the current flowing through the focusing electrode 12b and the voltage at the focusing electrode 12b can be provided.

[0042] Also, by time management, the voltage application by the power supply 40 can be terminated. For example, the voltage application by the power supply 40 can be terminated using the recovery time obtained in advance through experiments or simulations.

[0043] Also, as described above, when emitting X-rays, the focusing electrode 12b is preferably connected to the ground or a negative voltage is applied to converge electrons. Therefore, when emitting X-rays, the power supply 40 can stop applying a positive voltage to the focusing electrode 12b so that the focusing electrode 12b has a ground potential. Also, the power supply 40 can apply a negative voltage to the focusing electrode 12b when emitting X-rays, and can apply a positive voltage to the focusing electrode 12b when recovering the amount of electrons emitted from the cathode 12. That is, the power supply 40 may be capable of switching the polarity and voltage value of the voltage applied to the focusing electrode 12b.

[0044] The controller 50 controls, for example, the stator 13c of the anode 13 provided in the X-ray tube 10, the cathode power supply 20, the high-voltage power supply 30, and the power supply 40. The controller 50 includes, for example, an arithmetic unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The controller 50 is, for example, a computer or the like.

[0045] The memory unit stores a control program for controlling the operations of the respective elements provided in the X-ray tube apparatus 1, data for control, and the like. The data for control can be, for example, the value of the voltage applied to the focusing electrode 12b when recovering the amount of electrons emitted from the cathode 12, the values of the tube current and tube voltage for determining the timing to start recovering the amount of electrons, the values of the current and voltage at the focusing electrode 12b for determining the timing to end the process of recovering the amount of electrons, the time used for time management, and the like. Note that the data for control can include general data used when emitting X-rays.

[0046] For example, the controller 50 controls the operations of the stator 13c of the anode 13, the cathode power supply 20, the high-voltage power supply 30, and the power supply 40 based on the control program and data stored in the memory unit, and causes the X-ray tube 10 to emit X-rays.

[0047] For example, the controller 50 controls the operations of the cathode power supply 20 and the power supply 40 based on the control program and data stored in the memory unit, and recovers the amount of electrons emitted from the cathode 12.

[0048] In this case, the controller 50 can control the cathode power supply 20 and the power supply 40 based on the detection value from the detection unit 30a. When the detection value from the detection unit 30a becomes equal to or less than a predetermined value, the controller 50 controls the cathode power supply 20 to emit electrons from the electron source. Further, the controller 50 controls the power supply 40 to apply a positive voltage to the focusing electrode 12b.

[0049] In this case, when the controller 50 controls the power supply 40 to apply a positive voltage to the focusing electrode 12b, the controller 50 can control the high-voltage power supply 30 so as not to apply a high voltage between the anode 13 and the filament 12a.

[0050] Further, after applying a positive voltage to the focusing electrode 12b, when the detection value from the detection unit 40a becomes equal to or greater than a predetermined value, the controller 50 can control the cathode power supply 20 to stop applying the voltage to the electron source. Further, the controller 50 can control the power supply 40 to stop applying the positive voltage to the focusing electrode 12b.

[0051] Further, after applying a positive voltage to the focusing electrode 12b, when a predetermined time has elapsed, the controller 50 controls the cathode power supply 20 to stop applying the voltage to the electron source. Further, the controller 50 can control the power supply 40 to stop applying the positive voltage to the focusing electrode 12b.

[0052] Further, the power supply 40 can be made capable of switching between the positive voltage applied to the focusing electrode 12b and the negative voltage. In this case, after stopping the application of the positive voltage to the focusing electrode 12b, the controller 50 can control the power supply 40 to continue to stop the application of the positive voltage to the focusing electrode 12b or apply a negative voltage to the focusing electrode 12b. Then, the controller 50 can control the cathode power supply 20 to apply a voltage to the electron source to emit electrons from the electron source, and control the high-voltage power supply 30 to apply a voltage between the anode 13 and the filament 12a.

[0053] Further, the treatment method of the X-ray tube device according to the present embodiment is a treatment method of an X-ray tube device including an electron source capable of emitting electrons and a focusing electrode 12b surrounding the electron source. In the treatment method of the X-ray tube device, when at least one of the tube current and the tube voltage becomes equal to or less than a predetermined value, a voltage is applied to the electron source to emit electrons from the electron source, and a positive voltage is applied to the focusing electrode 12b.

[0054] In this case, when at least one of the tube current and the tube voltage becomes equal to or less than a predetermined value, a warning can be issued to the user of the X-ray tube device. Note that the content of the treatment method of the X-ray tube device can be the same as that described above, so detailed description thereof will be omitted.

[0055] (X-ray device) Next, an example of the X-ray device 100 will be given. Examples of the X-ray device 100 include, for example, an X-ray imaging diagnostic device used for medical diagnosis, an X-ray inspection device used for non-destructive inspection, an X-ray thickness measurement device for measuring the thickness of plate materials such as iron and copper alloys, and the like. However, the X-ray device 100 is not limited to the examples given, and any device may be used as long as it includes an X-ray tube device 1 and an X-ray detection device capable of detecting X-rays emitted from the X-ray tube device 1 and transmitted through an object. In the following, as an example, a case where the X-ray device 100 is an X-ray imaging diagnostic device will be described.

[0056] FIG. 4 is a block diagram for exemplifying the X-ray device 100 according to the present embodiment. As shown in FIG. 4, the X-ray device 100 is provided with, for example, an X-ray tube device 1, an X-ray detection device 101, a controller 102, and a display unit 103.

[0057] The X-ray detection device 101 can be an X-ray sensor that detects X-rays emitted from the X-ray tube device 1 and transmitted through the object 200. The X-ray sensor may be an indirect conversion type X-ray sensor or a direct conversion type X-ray sensor. The indirect conversion type X-ray sensor converts X-rays into fluorescence (visible light) by a scintillator and converts the fluorescence into charges by a photoelectric conversion element such as a photodiode. The direct conversion type X-ray sensor detects the photoconductive charges generated inside the photoconductive film by X-rays.

[0058] The controller 102 includes, for example, an arithmetic unit such as a CPU and a storage unit such as a memory. The controller 102 is, for example, a computer or the like.

[0059] The memory unit stores a control program for controlling the operations of each element provided in the X-ray apparatus 100, data for performing control, and the like. The memory unit also stores a program for constructing an X-ray image using the data detected by the X-ray detector 101. Since known technologies can be applied to the control program for controlling the operations of each element, the program for constructing an X-ray image, etc., detailed descriptions thereof are omitted.

[0060] The display unit 103 displays, for example, the constructed X-ray image, the state of the X-ray apparatus 100, and the like. The display unit 103 can be, for example, a liquid crystal panel display or the like. In addition, an input unit for inputting instructions and data to the controller 102 can also be provided. The input unit is, for example, a keyboard, a mouse, or the like.

[0061] Here, when the object 200 is a human body, irradiating the human body with a large amount of X-rays has an adverse effect on health. Therefore, when the X-ray apparatus 100 is an X-ray diagnostic apparatus, the X-ray irradiation dose to the object 200 (human body) is suppressed to the minimum necessary. As a result, the intensity of the X-rays that pass through the object 200 and enter the X-ray detector 101 becomes extremely weak.

[0062] In such a case, if the decrease in the amount of electrons emitted from the cathode 12 described above occurs, the intensity of the X-rays incident on the X-ray detector 101 becomes even weaker, and the quality of the obtained X-ray image may be significantly deteriorated.

[0063] As described above, since the X-ray tube device 1 is provided with the power supply 40, the amount of electrons emitted from the cathode 12 can be restored. Therefore, it becomes easy to maintain the quality of the obtained X-ray image.

[0064] This also applies to the case where the X-ray apparatus is a non-destructive inspection apparatus, an X-ray thickness measurement apparatus, or the like. However, the effect of restoring the amount of electrons emitted from the cathode 12 is more important in the case of an X-ray diagnostic apparatus.

[0065] The above has illustrated the embodiments. However, the present invention is not limited to these descriptions. Regarding the foregoing embodiments, those in which a person skilled in the art appropriately adds, deletes, or changes the design of components, or adds, omits, or changes conditions of steps, are also included in the scope of the present invention as long as they have the features of the present invention.

[0066] The following shows appendices regarding the foregoing embodiments.

[0067] (Appendix 1) An X-ray tube device comprising: an electron source capable of emitting electrons when a voltage is applied; a focusing electrode surrounding the electron source; an anode capable of generating X-rays when the electrons emitted from the electron source are incident thereon; a cathode power source capable of applying the voltage to the electron source; a power source capable of applying a positive first voltage to the focusing electrode;

[0068] (Appendix 2) An outer container in which the electron source, the focusing electrode, and the anode are provided; a high-voltage power source capable of applying a positive voltage to the anode; a first detection unit capable of detecting at least one of tube current and tube voltage in the outer container; a controller capable of controlling the cathode power source and the power source based on a detection value from the first detection unit; further comprising: when the detection value from the first detection unit becomes equal to or less than a predetermined value, the controller controls the cathode power source to cause the electron source to emit the electrons, and controls the power source to apply the positive first voltage to the focusing electrode. The X-ray tube device according to Appendix 1.

[0069] (Appendix 3) The controller is further capable of controlling the high-voltage power source. The X-ray tube device according to appended note 2, wherein when the controller controls the power supply to apply the positive first voltage to the focusing electrode, the controller controls the high-voltage power supply not to apply the positive voltage to the anode.

[0070] (Appended note 4) The X-ray tube device according to appended note 2 or 3, further comprising a second detection unit capable of detecting at least one of the current flowing through the focusing electrode and the voltage at the focusing electrode. The X-ray tube device according to appended note 2 or 3, wherein after the controller applies the positive first voltage to the focusing electrode, when the detection value from the second detection unit becomes equal to or greater than a predetermined value, the controller controls the cathode power supply to stop applying the voltage to the electron source, and controls the power supply to stop applying the positive first voltage to the focusing electrode.

[0071] (Appended note 5) The X-ray tube device according to appended note 2 or 3, wherein after the controller applies the positive first voltage to the focusing electrode, when a predetermined time has elapsed, the controller controls the cathode power supply to stop applying the voltage to the electron source, and controls the power supply to stop applying the positive first voltage to the focusing electrode.

[0072] (Appended note 6) The power supply is further capable of switching between the positive first voltage applied to the focusing electrode and a negative second voltage, and after the controller stops applying the positive first voltage to the focusing electrode, the controller controls the power supply to continue stopping the application of the positive first voltage to the focusing electrode or to apply the negative second voltage to the focusing electrode, controls the cathode power supply to apply the voltage to the electron source to emit electrons from the electron source, The X-ray tube apparatus according to any one of Appendices 2 to 5, which controls the high-voltage power supply to apply the positive voltage to the anode.

[0073] (Appendix 7) An X-ray tube apparatus according to any one of Appendices 1 to 6, an X-ray detection apparatus capable of detecting X-rays emitted from the X-ray tube apparatus and transmitted through an object, and an X-ray apparatus comprising the same.

[0074] (Appendix 8) A treatment method for an X-ray tube apparatus comprising an electron source capable of emitting electrons and a focusing electrode surrounding the electron source, wherein when at least one of the tube current and the tube voltage becomes equal to or less than a predetermined value, a voltage is applied to the electron source to emit the electrons from the electron source, and a positive first voltage is applied to the focusing electrode.

[0075] (Appendix 9) The treatment method for an X-ray tube apparatus according to Appendix 8, wherein when at least one of the tube current and the tube voltage becomes equal to or less than the predetermined value, a warning is issued to a user of the X-ray tube apparatus.

Description of Reference Numerals

[0076] 1 X-ray tube apparatus, 10 X-ray tube, 11 outer enclosure, 12 cathode, 12a filament, 12b focusing electrode, 13 anode, 20 cathode power supply, 30 high-voltage power supply, 30a detection unit, 40 power supply, 40a detection unit, 50 controller, 100 X-ray apparatus, 101 X-ray detection apparatus, 200 object

Claims

1. An electron source capable of emitting electrons when a voltage is applied, A focusing electrode surrounding the electron source, An anode capable of generating X-rays when the electrons emitted from the electron source are incident thereon, A cathode power source capable of applying the voltage to the electron source, A power source capable of applying a positive first voltage to the focusing electrode, An X-ray tube device comprising the same.

2. An outer container provided therein with the electron source, the focusing electrode, and the anode, A high-voltage power source capable of applying a positive voltage to the anode, A first detection unit capable of detecting at least one of the tube current and the tube voltage in the outer container, A controller capable of controlling the cathode power source and the power source based on a detection value from the first detection unit, Further comprising, When the detection value from the first detection unit becomes equal to or less than a predetermined value, the controller Controls the cathode power source to emit the electrons from the electron source, Controls the power source to apply the positive first voltage to the focusing electrode. The X-ray tube device according to claim 1.

3. The controller is further capable of controlling the high-voltage power source, When the controller controls the power source to apply the positive first voltage to the focusing electrode, the controller controls the high-voltage power source not to apply the positive voltage to the anode. The X-ray tube device according to claim 2.

4. Further comprising a second detection unit capable of detecting at least one of the current flowing through the focusing electrode and the voltage at the focusing electrode, After the controller applies the positive first voltage to the focusing electrode, when the detection value from the second detection unit becomes equal to or greater than a predetermined value, the controller Control the cathode power supply to stop applying the voltage to the electron source, The X-ray tube device according to claim 2, wherein the power supply is controlled to stop applying the positive first voltage to the focusing electrode.

5. After applying the positive first voltage to the focusing electrode, when a predetermined time has elapsed, the controller Controls the cathode power supply to stop applying the voltage to the electron source, The X-ray tube device according to claim 2, wherein the power supply is controlled to stop applying the positive first voltage to the focusing electrode.

6. The power supply is further capable of switching between the positive first voltage applied to the focusing electrode and a negative second voltage, After stopping the application of the positive first voltage to the focusing electrode, the controller Controls the power supply to continue stopping the application of the positive first voltage to the focusing electrode or to apply the negative second voltage to the focusing electrode, Controls the cathode power supply to apply the voltage to the electron source to emit electrons from the electron source, The X-ray tube device according to claim 4 or 5, wherein the high-voltage power supply is controlled to apply the positive voltage to the anode.

7. An X-ray tube device according to any one of claims 1 to 5, An X-ray detection device capable of detecting X-rays emitted from the X-ray tube device and transmitted through an object, An X-ray device comprising the same.

8. A treatment method for an X-ray tube device including an electron source capable of emitting electrons and a focusing electrode surrounding the electron source, comprising: When at least one of the tube current and the tube voltage becomes equal to or less than a predetermined value, A treatment method for an X-ray tube device, which applies a voltage to the electron source to emit electrons from the electron source and applies a positive first voltage to the focusing electrode.

9. The treatment method for an X-ray tube device according to claim 8, wherein when at least one of the tube current and the tube voltage becomes equal to or less than the predetermined value, a warning is issued to the user of the X-ray tube device.

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