X-ray generator

Abstract

To provide an x-ray generator which can easily detect gas generated in an insulation part.SOLUTION: An x-ray generator 1A includes: an x-ray tube 2 for generating x-rays; a power supply unit 5 for generating a voltage to be applied to the x-ray tube 2; a housing part 3 for accommodating at least a part of the x-ray tube 2; a first liquid insulating part 4 sealed in the housing part 3 and covering at least a part of the x-ray tube 2; and a gas sensor 7 with a detection unit 7a disposed in the housing part 3, for detecting gas generated in the first insulating part 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an X-ray generating device. [Background technology]

[0002] Known X-ray generating devices include an X-ray tube that generates X-rays, a power supply unit that generates a voltage to be applied to the X-ray tube, a housing unit that houses at least a portion of the X-ray tube, and a liquid insulating unit that is sealed in the housing unit and covers at least a portion of the X-ray tube (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6190563 Summary of the Invention [Problem to be solved by the invention]

[0004] In the X-ray generator described above, thermal decomposition of the insulating part may occur due to discharge generated within the insulating part. In this case, the insulating performance of the insulating part may deteriorate, which may reduce the operational stability of the X-ray generator. In order to maintain the operational stability of the X-ray generator, it is important to check the degree of deterioration of the insulating performance of the insulating part by detecting the gas generated as a derivative of the thermal decomposition of the insulating part within the insulating part.

[0005] An object of the present invention is to provide an X-ray generator that can easily detect gas generated in an insulating part. [Means for solving the problem]

[0006] The X-ray generating device of the present invention is [1] "an X-ray generating device comprising: an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing unit that houses at least a portion of the X-ray tube; a liquid first insulating unit that is sealed in the housing unit and covers at least the portion of the X-ray tube; and a gas sensor that has a detection unit located in the housing unit and detects gas generated in the first insulating unit."

[0007] In the X-ray generator described in [1] above, a gas sensor detection unit is disposed in a housing unit in which a liquid first insulating unit is sealed. This gas sensor can detect gas generated in the first insulating unit. Therefore, the X-ray generator described in [1] above makes it possible to easily detect gas generated in the first insulating unit.

[0008] The X-ray generator of the present invention may be [2] "the X-ray generator according to the above [1], in which the detection unit is disposed in the first insulating part." According to the X-ray generator according to [2], the detection unit of the gas sensor is disposed in the first insulating part, which is the gas generation source, and thus the gas generated in the first insulating part can be detected efficiently, and therefore the gas generated in the first insulating part can be detected easily and efficiently.

[0009] The X-ray generator of the present invention may be [3] "the X-ray generator according to the above [1] or [2], wherein the detection unit is disposed in the housing so as not to overlap with the at least part of the X-ray tube when viewed from either a predetermined direction in which the at least part of the X-ray tube and the power supply unit are aligned or any direction perpendicular to the predetermined direction." The X-ray generator according to [3] can suppress the occurrence of discharge between at least a part of the X-ray tube and the detection unit of the gas sensor.

[0010] The X-ray generating device of the present invention is [4] "an X-ray generating device comprising: an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing unit that houses at least a portion of the X-ray tube; and a liquid first insulating part that is sealed in the housing unit and covers at least the portion of the X-ray tube, wherein the housing unit is provided with an outlet that connects the inside of the housing unit to the outside of the housing unit."

[0011] In the X-ray generator described in [4] above, the housing in which the liquid first insulating part is sealed is provided with an outlet that connects the inside of the housing to the outside of the housing. This allows the first insulating part to be easily removed from the inside of the housing through this outlet. Then, by analyzing the removed first insulating part, gas generated in the first insulating part can be detected. Therefore, the X-ray generator described in [4] above makes it possible to easily detect gas generated in the first insulating part.

[0012] The X-ray generator of the present invention may be [5] "the X-ray generator according to the above [4], further comprising a pipe connected to the exhaust port and an opening / closing unit provided in the pipe and capable of opening and closing the inside of the pipe." According to the X-ray generator according to [5], it is possible to easily realize a configuration that prevents leakage of the first insulating part from the housing unit while removing the first insulating part from the inside of the housing unit through the exhaust port.

[0013] The X-ray generating device of the present invention is [6] "an X-ray generating device comprising: an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing unit that houses at least a portion of the X-ray tube; and a liquid first insulating unit that is sealed in the housing unit and covers at least the portion of the X-ray tube, wherein at least a portion of the housing unit is formed from a material that is transparent to light having a predetermined wavelength."

[0014] In the X-ray generator described in [6] above, at least a portion of the housing unit is formed from a material that is transmissive to light having a predetermined wavelength. This allows light having the predetermined wavelength to be incident on the first insulating unit inside the housing unit via at least a portion of the housing unit, making it possible to easily obtain transmitted light, reflected light, etc. from the first insulating unit. By analyzing this transmitted light, reflected light, etc., it is possible to detect gas generated in the first insulating unit. Therefore, the X-ray generator described in [6] above makes it possible to easily detect gas generated in the first insulating unit.

[0015] The X-ray generator of the present invention may be [7] "the X-ray generator according to the above [6], wherein the at least one portion of the housing unit is a plurality of portions located on both sides of the first insulating unit in a predetermined direction." According to the X-ray generator according to [7], transmitted light traveling along the predetermined direction can be more easily obtained through the plurality of portions located on both sides of the first insulating unit.

[0016] The X-ray generator of the present invention may be [8] "the X-ray generator according to any one of the above [1] to [7], wherein the power supply unit has a second insulating unit and a circuit unit embedded in the second insulating unit, and the circuit unit has a first voltage unit to which a first voltage is input from the outside, a boost unit that boosts the first voltage to a second voltage that is the first voltage, and a second voltage unit that outputs the second voltage to the X-ray tube." According to the X-ray generator described in [8], the second insulating unit insulates the circuit unit from other members. This makes it possible to suppress discharge within the power supply unit, thereby improving the operational stability of the X-ray generator.

[0017] The X-ray generator of the present invention may be [9] "the X-ray generator according to any one of [1] to [7] above, wherein the power supply unit has a circuit unit including a first voltage unit to which a first voltage is input from the outside, a boost unit that boosts the first voltage to a second voltage that is the first voltage, and a second voltage unit that outputs the second voltage to the X-ray tube, the housing unit further houses the circuit unit, and the first insulating unit further covers the circuit unit." According to the X-ray generator described in [9], the X-ray tube and the circuit unit can be easily insulated from each other by a single type of first insulating unit. Furthermore, gas can be easily detected even with a first insulating unit configured in this way. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an X-ray generator that can easily detect gas generated in an insulating part. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view of an X-ray generator according to a first embodiment. [Figure 2] FIG. 10 is a cross-sectional view of an X-ray generator according to a second embodiment. [Figure 3] FIG. 10 is a cross-sectional view of an X-ray generator according to a third embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a modified X-ray generating device. [Figure 5] FIG. 10 is a cross-sectional view of a modified X-ray generating device. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted. [X-ray generating device of the first embodiment]

[0021] 1, the X-ray generator 1A of the first embodiment includes an X-ray tube 2, a housing unit 3, a first insulating unit 4, a power supply unit 5, a conductive member 6, a gas sensor 7, and conductive paint 8. The X-ray generator 1A is a microfocus X-ray source used, for example, in X-ray nondestructive testing.

[0022] The X-ray tube 2 is a vacuum tube for generating X-rays. The X-ray tube 2 includes a housing 21, an electron gun 22, a target 23, and an anode 24. The housing 21 houses the electron gun 22, the target 23, and the anode 24. The space inside the housing 21 is a vacuum-drawn space. The housing 21 includes a head 211, a bulb 212, and a flange 213. The head 211 is formed into a cylindrical shape with a bottom from a metal material such as stainless steel. The bulb 212 is formed into a cylindrical shape with a bottom from an insulating material such as glass. The head 211 is airtightly joined to the bulb 212 so that the interior of the head 211 is in communication with the interior of the bulb 212. The flange 213 is formed into a circular shape along the outer edge of the head 211 from a metal material such as stainless steel. Here, the direction along the central axis (tube axis) A1 of the bulb 212 is referred to as the Z-axis direction, the direction perpendicular to the Z-axis direction is referred to as the X-axis direction, and the direction perpendicular to both the Z-axis direction and the X-axis direction is referred to as the Y-axis direction.

[0023] The electron gun 22 emits an electron beam toward the target 23 inside the housing 21. The electron gun 22 is composed of a hot cathode that emits thermal electrons, an anode that accelerates the electrons, and an electron lens that adjusts the convergence of the electron beam (all of which are not shown). The electron gun 22 is fixed to the head 211 so that the central axis A2 of the electron gun 22 is perpendicular to the central axis A1 of the bulb 212. The central axis A2 of the electron gun 22 is aligned along the X-axis direction.

[0024] The target 23 generates X-rays when the electron beam emitted from the electron gun 22 is incident on the target 23 within the housing 21. The target 23 is formed into a plate shape from a high-melting-point metal material such as tungsten. The target 23 is supported by an anode 24 within the housing 21 so as to face the electron gun 22 in the X-axis direction.

[0025] The anode 24 applies a voltage generated in the power supply unit 5 to the target 23. Therefore, the anode 24 is electrically connected to the target 23. The anode 24 is formed in a rod shape extending along the Z-axis direction from a metal material such as copper. The anode 24 extends from outside the housing 21 to inside the housing 21 so that the central axis of the anode 24 coincides with the central axis A1 of the bulb 212. The anode 24 is fixed to the bottom of the bulb 212. The tip surface of the anode 24 inside the housing 21 is an inclined surface inclined with respect to both the central axis A1 and the central axis A2. The target 23 is embedded in a tip portion 24a of the anode 24 so as to be flush with the tip surface of the anode 24.

[0026] The housing unit 3 houses a part of the X-ray tube 2. In the X-ray generator 1A of the first embodiment, the housing unit 3 houses the bulb 212. The housing unit 3 is formed in a cylindrical shape with a bottom and made of a metal material such as aluminum. The housing unit 3 has an upper portion 31 and a side portion 32. The side portion 32 is formed in a cylindrical shape with its height direction in the Z-axis direction. The upper portion 31 closes one end (the upper end in this embodiment) of the side portion 32 in the Z-axis direction. An opening 31a is provided in the upper portion 31. The X-ray tube 2 is located inside the opening 31a. The flange 213 is fixed to the upper portion 31 with the bulb 212 located inside the housing unit 3. The other end (the lower end in this embodiment) of the side portion 32 in the Z-axis direction is fixed to the upper end of the power supply unit 5 (the upper surface 51b of the second insulating portion 51). A first insulating portion 4 is sealed inside the housing unit 3.

[0027] The first insulating part 4 electrically insulates the X-ray tube 2 from other components. The first insulating part 4 is a liquid insulating part. The first insulating part 4 is, for example, insulating oil whose main component is mineral oil or ester oil. Inside the accommodation part 3, the first insulating part 4 covers the bulb 212, the part of the anode 24 that is exposed to the outside of the housing 21, and the part of the conductive member 6 that is exposed to the outside of the second insulating part 51. In the X-ray generator 1A of the first embodiment, the inside of the accommodation part 3 is filled with the first insulating part 4.

[0028] The power supply unit 5 generates a voltage to be applied to the target 23 via the conductive member 6 and the anode 24. The power supply unit 5 is disposed on one side of the housing 21 in the Z-axis direction (below the housing 21). The power supply unit 5 is aligned with the X-ray tube 2 along the Z-axis direction. The power supply unit 5 has a second insulating unit 51 and a circuit unit 52.

[0029] The second insulating portion 51 is a solid insulating portion that electrically insulates the circuit portion 52 from other components. The second insulating portion 51 is formed in a rectangular parallelepiped shape using a resin material such as epoxy resin. The surface 51a of the second insulating portion 51 is composed of an upper surface 51b that faces the housing 21, a lower surface 51c that is opposite the upper surface 51b, and a side surface 51d that connects the upper surface 51b and the lower surface 51c to each other. A portion of the upper surface 51b is formed to be raised. This portion is in contact with the first insulating portion 4 inside the housing portion 3. The conductive paint 8 is applied to the side surface 51d of the second insulating portion 51, and the potential of the side surface 51d is set to ground potential.

[0030] The circuit unit 52 has a substrate 521, which is a rectangular printed circuit board. The surface of the substrate 521 is perpendicular to the Y-axis direction. A first voltage unit 52a, a boost unit 52b, and a second voltage unit 52c are mounted on the surface of the substrate 521. The first voltage unit 52a is an input terminal to which a first voltage is input from outside and is electrically connected to the boost unit 52b. The boost unit 52b boosts the first voltage to a second voltage. The boost unit 52b is, for example, a Cockcroft-Walton circuit. The second voltage unit 52c is an output terminal that outputs a second voltage to the target 23 via the conductive member 6 and the anode 24 and is electrically connected to the boost unit 52b.

[0031] The booster 52b is located in the center of the surface of the substrate 521. The first voltage unit 52a is located on one side of the booster 52b in the Z-axis direction (toward the lower surface 51c). The second voltage unit 52c is located on the other side of the booster 52b in the Z-axis direction (toward the upper surface 51b).

[0032] The circuit section 52 is embedded in the second insulating section 51 so that the entire circuit section 52 is located in the second insulating section 51. The circuit section 52 is embedded in the second insulating section 51 so that the substrate 521 extends straight along the Z-axis direction.

[0033] The conductive member 6 electrically connects the second voltage unit 52c and the target 23 via the anode 24. Therefore, the conductive member 6 is conductive. The conductive member 6 is formed in a rod shape using a metal material such as aluminum. One end of the conductive member 6 is electrically connected to the second voltage unit 52c, and the other end of the conductive member 6 is electrically connected to the base end 24b of the anode 24 (a portion of the anode 24 located outside the housing 21). The conductive member 6 is embedded in the second insulating portion 51 so that a portion of the conductive member 6 is located within the second insulating portion 51. The other portion of the conductive member 6 is exposed outside the second insulating portion 51. The portion of the conductive member 6 exposed outside the second insulating portion 51 is electrically connected to the base end 24b of the anode 24 inside the housing 3.

[0034] The gas sensor 7 detects gas generated within the first insulating part 4. The gas sensor 7 has a configuration according to the type of gas to be detected. The gas sensor 7 is composed of a detection part 7a and a control part 7b. The control part 7b functions, for example, as a voltage application part that applies a voltage to drive the detection part 7a and a signal processing part that processes a detection signal from the detection part 7a. The detection part 7a is disposed within the housing part 3. In the X-ray generator 1A of the first embodiment, the detection part 7a is disposed within the first insulating part 4. That is, the detection part 7a is immersed in the first insulating part 4. The detection part 7a is electrically connected to the control part 7b that is disposed outside the housing part 3. The control part 7b may be disposed within the power supply part 5. For example, the control part 7b may be mounted on the substrate 521. Alternatively, the control part 7b may be mounted on a substrate different from the substrate 521, and the substrate may be embedded in the second insulating part 51.

[0035] The gas sensor 7 is, for example, an NDIR (Non Dispersive Infrared) gas sensor. NDIR gas sensors detect gas by utilizing the property of gas molecules to absorb infrared light having a specific wavelength. When the gas sensor 7 is an NDIR gas sensor, the detection unit 7a has a light-emitting element and a light-receiving element. The light-emitting element is a light-emitting element that emits infrared light of a specific wavelength and is electrically connected to the control unit 7b. The light-receiving element is a light-receiving element that absorbs the infrared light emitted from the light-emitting element and is electrically connected to the control unit 7b. The light-receiving element outputs a signal corresponding to the amount of infrared light absorbed to the control unit 7b. When gas (e.g., acetylene gas) is present in the first insulating unit 4, some of the infrared light emitted from the light-emitting element is absorbed by the gas, thereby reducing the amount of infrared light reaching the light-receiving element. The control unit 7b calculates the gas concentration based on the signal amount detected from the light-receiving element. When the gas to be detected is acetylene gas, the light-emitting element emits infrared light having a wavelength of, for example, 2.9 μm to 3.1 μm. The infrared rays are infrared rays that can be absorbed by the molecular structure specific to acetylene.

[0036] The gas sensor 7 may be a gas sensor other than an NDIR gas sensor. For example, the gas sensor 7 may be a semiconductor gas sensor in which the detection unit 7a includes a substrate layer, a semiconductor layer, a gate electrode, and an ohmic contact. The substrate layer is a substrate made of, for example, sapphire. The semiconductor layer is formed on the substrate layer by epitaxial growth. The gate electrode and the ohmic contact are evaporated on the semiconductor layer. The gate electrode is made of a metal material such as platinum. The ohmic contact is a Ti / Al layer or a Ti / Pt / Au layer formed by electron beam evaporation. The control unit 7b is electrically connected to the gate electrode and the ohmic contact. When gas (e.g., hydrogen gas) is generated in the first insulating unit 4, the hydrogen gas is adsorbed on the gate electrode, dissociating the hydrogen molecules into hydrogen atoms. These hydrogen atoms reach the interface between the gate electrode and the semiconductor layer via the gate electrode. This changes the height of the Schottky barrier at the interface, thereby changing the resistance between the gate electrode and the ohmic contact. The control unit 7b applies a constant voltage between the gate electrode and the ohmic contact and measures the change in the current flowing between the gate electrode and the ohmic contact. Alternatively, the control unit 7b may apply a constant current between the gate electrode and the ohmic contact and measure the change in the voltage between the gate electrode and the ohmic contact. The amount of change in the Schottky barrier height increases as the gas concentration increases. Using this fact, the control unit 7b may calculate the gas concentration in the first insulating unit 4.

[0037] The detection unit 7a of the gas sensor 7 is disposed within the housing 3 so as not to overlap with a portion of the X-ray tube 2 housed within the housing 3 when viewed from the Z-axis direction or any direction perpendicular to the Z-axis direction. For example, the detection unit 7a does not overlap with the bulb 212 or the portion of the anode 24 exposed to the outside of the housing 21 when viewed from the X-axis direction, the Y-axis direction, or the Z-axis direction. The shortest distance between the detection unit 7a and the X-ray tube 2 is greater than the shortest distance between the detection unit 7a and the side portion 32. The shortest distance between the detection unit 7a and the X-ray tube 2 is greater than the shortest distance between the detection unit 7a and the second insulating portion 51. The shortest distance between the detection unit 7a and the conductive member 6 is greater than the shortest distance between the detection unit 7a and the side portion 32. The shortest distance between the detection unit 7a and the conductive member 6 is greater than the shortest distance between the detection unit 7a and the second insulating portion 51.

[0038] In this embodiment, the target 23 embedded in the tip 24a of the anode 24 is located outside the housing 3, whereas the detection unit 7a is disposed inside the housing 3. This makes it possible to prevent X-rays generated from the target 23 from adversely affecting the detection unit 7a.

[0039] In the X-ray generator 1A configured as described above, the side surface 51d of the second insulating unit 51 is set to ground potential, and a voltage of, for example, several hundred volts is input as a first voltage from an external power supply to the first voltage unit 52a. The booster unit 52b boosts the first voltage to a second voltage of, for example, several kV to several hundred kV. The second voltage unit 52c then outputs the second voltage to the target 23 via the conductive member 6 and the anode 24. With the second voltage applied to the target 23, an electron beam from the electron gun 22 is incident on the target 23, causing X-rays to be generated from the target 23. The X-ray generator 1A is a so-called sealed reflection X-ray generator. The application of a negative voltage to the electron gun 22 may be performed by a transformer (not shown) included in the power supply unit 5 or by the circuit unit 52.

[0040] As described above, in the X-ray generator 1A, the second voltage generated by the power supply unit 5 is applied to the target 23 (X-ray tube 2). Application of the second voltage to the X-ray tube 2 may cause discharge within the first insulating unit 4. If the first insulating unit 4 is made of insulating oil primarily composed of mineral oil or ester oil, the discharge causes thermal decomposition of the first insulating unit 4. When thermal decomposition occurs due to discharge, decomposition products are generated, along with the generation of acetylene gas and hydrogen gas. The greater the amount of decomposition products within the first insulating unit 4, the more the insulating performance of the first insulating unit 4 deteriorates. Acetylene gas and hydrogen gas are both gases characteristic of thermal decomposition caused by discharge. According to the X-ray generator 1A, by detecting acetylene gas or hydrogen gas using the gas sensor 7, it is possible to indirectly check whether an abnormal phenomenon (discharge) has occurred in the first insulating unit 4 and the degree of deterioration of the insulating performance.

[0041] As described above, in the X-ray generator 1A, the detection unit 7a is disposed in the housing 3 in which the liquid first insulating unit 4 is sealed. The gas sensor 7 having the detection unit 7a can detect gas generated in the first insulating unit 4. Therefore, with the X-ray generator 1A, it is possible to easily detect gas generated in the first insulating unit 4.

[0042] In the X-ray generating device 1A, the detection unit 7a is disposed inside the first insulating unit 4. By disposing the detection unit 7a inside the first insulating unit 4, which is the gas generation source, the gas generated inside the first insulating unit 4 can be detected efficiently, and therefore the gas generated inside the first insulating unit 4 can be detected easily and efficiently.

[0043] In the X-ray generator 1A, the detection unit 7a is arranged in the housing unit 3 so as not to overlap with a part of the X-ray tube 2 housed in the housing unit 3 when viewed from the Z-axis direction and any direction perpendicular to the Z-axis direction (for example, the X-axis direction and the Y-axis direction). This makes it possible to prevent discharge from occurring between the X-ray tube 2 and the detection unit 7a.

[0044] In the X-ray generator 1A, the power supply unit 5 has a second insulating unit 51 and a circuit unit 52 embedded in the second insulating unit 51, and the circuit unit 52 has a first voltage unit 52a to which a first voltage is input from the outside, a boost unit 52b that boosts the first voltage to a second voltage, and a second voltage unit 52c that outputs the second voltage to the X-ray tube 2. This insulates the circuit unit 52 from other components by the second insulating unit 51. This makes it possible to suppress the occurrence of discharge within the power supply unit 5, thereby improving the operational stability of the X-ray generator 1A. [X-ray generator according to the second embodiment]

[0045] 2, the X-ray generator 1B of the second embodiment differs from the X-ray generator 1A of the first embodiment mainly in that it includes a pipe 10 and an opening / closing unit 11. The X-ray generator 1B of the second embodiment will be described below, focusing on the differences from the X-ray generator 1A of the first embodiment. The X-ray generator 1B further includes a pipe 10 and an opening / closing unit 11.

[0046] The storage unit 3 has an upper portion 31 and a side portion 32. The side portion 32 is formed in a cylindrical shape with its height direction in the Z-axis direction. The upper portion 31 closes one end (the upper end in this embodiment) of the side portion 32 in the Z-axis direction. The side portion 32 is provided with an outlet 32a that connects the inside of the storage unit 3 to the outside of the storage unit 3.

[0047] The piping 10 is a cylindrical member for removing the first insulating part 4 from the storage part 3 to the outside of the storage part 3. The piping 10 is formed of a metal material such as stainless steel. The piping 10 is connected to the outlet 32a so that the inside of the piping 10 communicates with the inside of the storage part 3. The piping 10 is liquid-tightly connected to the outlet 32a so that the first insulating part 4 does not leak from between the piping 10 and the outlet 32a. The first insulating part 4 is removed to the outside of the storage part 3 via the outlet 32a and the piping 10.

[0048] The opening / closing unit 11 is a member that adjusts the flow of the first insulating part 4 in the pipe 10. The opening / closing unit 11 is provided in the pipe 10 and opens and closes the inside of the pipe 10. The opening / closing unit 11 is a valve such as a manual valve, an electric valve, or a solenoid valve.

[0049] In the X-ray generator 1B configured as described above, with the opening / closing unit 11 open, a part of the first insulating unit 4 inside the housing unit 3 can be taken out of the housing unit 3 via the outlet 32a and the piping 10. The taken-out part of the first insulating unit 4 can be analyzed using an analytical device such as gas chromatography to detect gas generated inside the first insulating unit 4.

[0050] As described above, in X-ray generator 1B, housing 3 in which liquid first insulating part 4 is sealed is provided with outlet 32a that connects the inside of housing 3 to the outside of housing 3. This allows first insulating part 4 to be easily removed from inside housing 3 via outlet 32a. Then, by analyzing the removed first insulating part 4, gas generated in first insulating part 4 can be detected. Therefore, X-ray generator 1B makes it possible to easily detect gas generated in first insulating part 4.

[0051] The X-ray generator 1B includes a pipe 10 connected to the exhaust port 32a, and an opening / closing unit 11 provided in the pipe 10 and capable of opening and closing the inside of the pipe 10. This makes it possible to easily realize a configuration that prevents leakage of the first insulating unit 4 from the housing unit 3 while removing the first insulating unit 4 from the inside of the housing unit 3 through the exhaust port 32a. [X-ray generator according to the third embodiment]

[0052] 3, the X-ray generator 1C of the third embodiment differs from the X-ray generator 1A of the first embodiment mainly in that at least a portion of the container 3 is made of a material that is transmissive to light having a predetermined wavelength. The following describes the X-ray generator 1C of the third embodiment, focusing on the differences from the X-ray generator 1A of the first embodiment.

[0053] The storage section 3 has an upper section 31 and a side section 32. The side section 32 is formed in a cylindrical shape with its height direction in the Z-axis direction. The upper section 31 closes one end (the upper end in this embodiment) of the side section 32 in the Z-axis direction.

[0054] A portion 321 of the side portion 32 is formed from a material that can transmit light having a predetermined wavelength. The portion 321 is formed, for example, in a circular shape. The material forming the portion 321 is appropriately selected depending on the value of the predetermined wavelength. For example, when infrared spectroscopy is used, the predetermined wavelength range is 2.5 μm or more and 25 μm or less. In order to be transparent to light in this wavelength range, the portion 321 is formed from an infrared-transmitting material such as quartz glass, diamond, sapphire, silicon, or germanium. The rest of the side portion 32 other than the portion 321 is formed from a metal material such as stainless steel or aluminum.

[0055] In the X-ray generator 1C configured as described above, gas generated within the first insulating unit 4 is detected as follows. First, incident light E1 emitted from a light source (not shown) travels toward the portion 321. The incident light E1 has a predetermined wavelength. The incident light E1 enters the interior of the container 3 from the outside of the container 3 via the portion 321. A portion of the incident light E1 is reflected as reflected light E2 containing chemical information about the first insulating unit 4. The reflected light E2 is acquired, for example, as follows. That is, the angle of incidence of the incident light E1 and the refractive indexes of the materials constituting the first insulating unit 4 and the portion 321 are adjusted so that the condition for total reflection is satisfied at the interface (contact surface) between the first insulating unit 4 and the portion 321. Then, the incident light E1 that is totally reflected at the interface is acquired as reflected light E2. Alternatively, by arranging a reflector inside the first insulating part 4 so as to reflect the incident light E1 toward a portion 321, the incident light E1 reflected by the reflector is acquired as reflected light E2. At least a portion of the reflected light E2 is emitted to the outside of the accommodating part 3 via the portion 321. The absorption (transmission) spectrum obtained from the incident light E1 and the reflected light E2 changes proportionally depending on the amount of gas generated in the first insulating part 4 (the amount of gas present in the first insulating part 4). By detecting the reflected light E2 with a photodetector (not shown) and analyzing the obtained absorption spectrum, the type and amount of gas generated in the first insulating part 4 can be estimated. When measuring acetylene gas present in the first insulating part 4, the amount and increasing trend of acetylene gas generated in the first insulating part 4 can be estimated by focusing on peaks due to the presence of acetylene gas observed in the wavelength range of 2.9 μm to 3.1 μm, which includes the characteristic absorption band of acetylene, and examining the peak intensity and its change over time. Therefore, with the X-ray generator 1C, it is possible to estimate the degree of deterioration of the first insulating part 4 from the amount and increasing trend of acetylene gas. In addition to the acetylene peak intensity, the abundance ratio of acetylene to ethane can be calculated by obtaining the intensity of the peak due to the presence of ethane gas observed in the wavelength range of 3.3 μm to 3.5 μm using a similar method.From the obtained abundance ratio, it can be inferred that when the amount of acetylene present is large, thermal decomposition caused by discharge is dominant, and when the amount of ethane present is large, thermal decomposition caused by overheating is dominant. In this way, it becomes possible to distinguish between the cause of deterioration of the first insulating part 4, namely, whether it is caused by discharge or by overheating.

[0056] As described above, in the X-ray generator 1C, the portion 321 of the housing unit 3 (side portion 32) is made of a material that is transmissive to light having a predetermined wavelength. This allows light having the predetermined wavelength to be incident on the first insulating portion 4 inside the housing unit 3 via the portion 321, making it possible to easily obtain reflected light from the first insulating portion 4. By analyzing the absorption spectrum obtained from this reflected light, it is possible to detect gas generated in the first insulating portion 4. Therefore, with the X-ray generator 1C, it is possible to easily detect gas generated in the first insulating portion 4. [Variations]

[0057] The present invention is not limited to the above-described embodiments. In the X-ray generator 1A of the first embodiment, the housing unit 3 houses at least a portion of the X-ray tube 2, but the configuration of the housing unit 3 is not limited thereto. For example, as shown in FIG. 4 , in the X-ray generator 1A, the housing unit 3 may further house a circuit unit 52, and the first insulating unit 4 may further cover the circuit unit 52. The housing unit 3 may further have a lower portion 33 that closes the other end (the lower end in this embodiment) of the side portion 32 in the Z-axis direction. In this case, a single type of first insulating unit 4 can easily insulate the X-ray tube 2 and the circuit unit 52 from other components. Gas can also be easily detected with a first insulating unit 4 configured in this manner. In the X-ray generator 1B of the second embodiment and the X-ray generator 1C of the third embodiment, the housing unit 3 may further house a circuit unit 52, and the first insulating unit 4 may further cover the circuit unit 52.

[0058] In the X-ray generator 1C of the third embodiment, the portion 321 of the container 3 is formed from a material that transmits light having a predetermined wavelength. However, the configuration of the container 3 is not limited thereto. For example, as shown in FIG. 5 , in the X-ray generator 1C, two portions 322 and 323 of the side portion 32 may be formed from a material that transmits light having a predetermined wavelength. The two portions 322 and 323 may be located on both sides of the first insulating portion 4 in the X-axis direction (predetermined direction). In this case, transmitted light traveling along the X-axis direction can be more easily acquired through the two portions 322 and 323 located on both sides of the first insulating portion 4. Specifically, incident light E1 traveling along the X-axis direction enters the container 3 through the portion 322. Part of the incident light E1 is absorbed by the first insulating portion 4, and the other part of the incident light E1 exits the container 3 as transmitted light through the portion 323. The absorption (transmission) spectrum obtained from this transmitted light and incident light E1 changes depending on the amount (abundance) of gas generated in the first insulating section 4. Therefore, by analyzing this transmitted light, it is possible to detect the gas generated in the first insulating section 4 and further to estimate the type and amount of gas. In the X-ray generator 1C, the number of parts of the container 3 made of a material that can transmit light having a predetermined wavelength may be three or more.

[0059] In the X-ray generator 1A of the first embodiment, the inside of the housing unit 3 is filled with the first insulating part 4, but a part of the inside of the housing unit 3 does not have to be filled with the first insulating part 4. In this case, the detection unit 7a may be disposed inside the housing unit 3 so as not to come into contact with the first insulating part 4.

[0060] In the X-ray generating device 1C of the third embodiment, a portion 321 of the storage section 3 is formed from a material that is capable of transmitting light having a predetermined wavelength, but in the X-ray generating device 1C, the entire storage section 3 may be formed from a material that is capable of transmitting light having a predetermined wavelength.

[0061] Although the X-ray generator 1B of the second embodiment includes the piping 10 and the opening / closing unit 11, the X-ray generator 1B does not necessarily have to include the piping 10 and the opening / closing unit 11. In this case, the X-ray generator 1B may include an opening / closing unit (for example, a lid) that can open and close the outlet 32a.

[0062] In the X-ray generator 1B of the second embodiment, the opening / closing unit 11 is a manual valve, a solenoid valve, or an electric valve, but the opening / closing unit 11 may be any unit capable of opening and closing the inside of the pipe 10, such as a lid.

[0063] In the X-ray generator 1A of the first embodiment, the X-ray generator 1B of the second embodiment, and the X-ray generator 1C of the third embodiment, the housing section 3 houses the valve 212, but it is sufficient if the housing section 3 houses at least a part of the X-ray tube 2.

[0064] The X-ray generator 1A of the first embodiment, the X-ray generator 1B of the second embodiment, and the X-ray generator 1C of the third embodiment are sealed reflection type X-ray generators, but each of the X-ray generators 1A, 1B, and 1C may be a sealed transmission type X-ray generator. [Explanation of symbols]

[0065] 1A, 1B, 1C...X-ray generator, 2...X-ray tube, 3...accommodation section, 4...first insulating section, 5...power supply section, 7...gas sensor, 7a...detection section, 10...piping, 11...opening / closing section, 32a...exhaust port, 51...second insulating section, 52...circuit section, 52a...first voltage section, 52b...boosting section, 52c...second voltage section, 321...part, 322, 323...part.

Claims

1. an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing portion housing at least a portion of the X-ray tube; a liquid first insulating portion sealed in the housing portion and covering at least the portion of the X-ray tube; a gas sensor having a detection unit disposed in the housing unit and configured to detect gas generated in the first insulating unit.

2. The X-ray generating device according to claim 1 , wherein the detection unit is disposed within the first insulating unit.

3. 3. The X-ray generating device according to claim 1, wherein the detection unit is arranged in the housing unit so as not to overlap with the at least part of the X-ray tube when viewed from either a predetermined direction in which the at least part of the X-ray tube and the power supply unit are aligned or an arbitrary direction perpendicular to the predetermined direction.

4. an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing portion housing at least a portion of the X-ray tube; a liquid first insulating portion sealed in the housing portion and covering at least the portion of the X-ray tube; The housing unit is provided with an outlet that connects the inside of the housing unit to the outside of the housing unit.

5. A pipe connected to the outlet; The X-ray generating device according to claim 4 , further comprising: an opening / closing unit provided in the piping, the opening / closing unit being capable of opening and closing the inside of the piping.

6. an X-ray tube that generates X-rays; a power supply unit that generates a voltage to be applied to the X-ray tube; a housing portion housing at least a portion of the X-ray tube; a liquid first insulating portion sealed in the housing portion and covering at least the portion of the X-ray tube; An X-ray generating device, wherein at least a portion of the container is formed from a material that is transmissive to light having a predetermined wavelength.

7. The X-ray generating device according to claim 6 , wherein the at least one portion of the housing portion is a plurality of portions located on both sides of the first insulating portion in a predetermined direction.

8. the power supply unit has a second insulating portion and a circuit portion embedded in the second insulating portion, 7. The X-ray generating device according to claim 1, wherein the circuit unit includes a first voltage unit to which a first voltage is input from an external device, a boost unit that boosts the first voltage to a second voltage that is the voltage, and a second voltage unit that outputs the second voltage to the X-ray tube.

9. the power supply unit has a circuit unit including a first voltage unit to which a first voltage is input from an external device, a boost unit that boosts the first voltage to a second voltage that is the voltage, and a second voltage unit that outputs the second voltage to the X-ray tube; the housing portion further houses the circuit portion, The X-ray generating device according to claim 1 , wherein the first insulating portion further covers the circuit portion.

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