X-ray module

Abstract

An X-ray module includes a frame having an opening portion, an electron gun that emits an electron beam, a target that emits X-rays generated by the incidence of the electron beam from an X-ray emission surface, an X-ray emission window that seals the opening portion and emits the X-rays to a first side in an axial direction, and a heat dissipation portion that is disposed outside the frame. The frame has a surface having a protruding portion protruding toward the first side, the opening portion is formed in the protruding portion, and the target is disposed in the opening portion. The heat dissipation portion has a first portion extending along the surface and thermally connected to the surface, and a second portion extending from the first portion to a second side opposite to the first side.

Description

TECHNICAL FIELD

[0001] One aspect of the present disclosure relates to an X-ray module. BACKGROUND

[0002] As an X-ray module, there is known a module in which an electron gun that emits an electron beam, and a target that generates X-rays by incidence of the electron beam are arranged in a frame, and the X-rays are output from an output window that blocks an opening portion of the frame (for example, refer to Japanese Patent No. 5179797). SUMMARY

[0003] Problem to be Solved by the Invention

[0004] In the X-ray module described above, there is a demand to reduce a FOD (Focus to Object Distance) at times. For example, in a case where the X-ray module is used in non-destructive inspection, if the FOD, which is a distance from an X-ray focus (a point of irradiation of the electron beam on the target) to an inspection object, is small, observation can be performed at a high magnification. Or, if the magnification is equal, the X-ray imaging element can be arranged in the vicinity of the X-ray source, and thus a bright image can be obtained.

[0005] Further, in the X-ray module described above, a conversion efficiency of the electron beam in the target to the X-rays is about 1%, and about 99% of the incident electron beam is heat. Therefore, in order to suppress a decrease in X-ray output due to damage of the target by heat, it is required to dissipate heat generated by the target well.

[0006] Therefore, an object of one aspect of the present disclosure is to provide an X-ray module that can suppress an increase in FOD while dissipating heat generated by a target well.

[0007] Means for Solving the Problem

[0008] The X-ray module according to one aspect of the present disclosure includes a frame that is formed with an opening portion, an electron gun that emits an electron beam in the frame, a target that has an electron incidence surface and an X-ray emission surface on a side opposite to the electron incidence surface, and that causes X-rays generated by incidence of the electron beam to the electron incidence surface to be emitted from the X-ray emission surface, an X-ray emission window that seals the opening portion and causes the X-rays emitted from the target to be emitted to a first side in an axial direction, and a heat dissipation portion that is arranged outside the frame, the frame has a surface that is formed with a protruding portion that protrudes to the first side, the opening portion is formed in the protruding portion, the target is arranged in the opening portion, and the heat dissipation portion has a first portion that extends along the surface and is thermally connected to the surface, and a second portion that extends from the first portion to a second side opposite to the first side.

[0009] In the X-ray module, the target has an electron incidence surface and an X-ray emission surface, and X-rays generated by incidence of an electron beam to the electron incidence surface are emitted from the X-ray emission surface. In such a transmission type structure, compared with a reflection type structure in which the electron incidence surface also serves as the X-ray emission surface, the target can be easily arranged in the vicinity of the X-ray emission window, and the FOD can be reduced. In addition, the protruding portion protruding toward the first side is formed on the surface of the frame, and the target is arranged in the opening portion formed in the protruding portion. Therefore, the FOD can be further reduced. Moreover, the heat dissipation portion has a first portion extending along the surface and thermally connected to the surface. Thus, the heat dissipation portion can be arranged using the space of the height of the protruding portion, the FOD can be inhibited from becoming large, and the heat generated in the target can be dissipated well. Moreover, the heat dissipation portion has a second portion extending from the first portion toward a second side opposite to the first side. Thus, the FOD can be inhibited from becoming large, and the heat dissipation property of the heat dissipation portion can be improved. Therefore, according to the X-ray module, the FOD can be inhibited from becoming large, and the heat generated in the target can be dissipated well.

[0010] The second portion can also be located outward of the outer edge of the surface when viewed in the axial direction, and can be located on the second side of the surface in the axial direction. In this case, the FOD can be inhibited from becoming large, and the heat dissipation property of the heat dissipation portion can be improved.

[0011] The first portion can also surround the protruding portion when viewed in the axial direction. In this case, the heat generated in the target can be dissipated more well.

[0012] The heat dissipation portion can also not protrude toward the first side with respect to the protruding portion. In this case, the FOD can be further reduced.

[0013] The surface of the first side of the heat dissipation portion can also be located on the same plane as the surface of the first side of the protruding portion. In this case, the FOD can be inhibited from becoming large, and the thickness of the first portion can be ensured to improve the heat dissipation property of the heat dissipation portion.

[0014] The surface of the first side of the X-ray emission window can also be located on the same plane as the surface of the first side of the heat dissipation portion. In this case, the FOD can be further reduced.

[0015] The X-ray module according to an aspect of the present disclosure can also further include a thermally conductive member arranged between the first portion and the surface. In this case, the heat generated in the target can be dissipated more well.

[0016] The second portion can also include a plurality of fins. In this case, the heat dissipation property of the heat dissipation portion can be further improved.

[0017] The first portion and the second portion can also be formed in a tubular shape. In this case, for example, the first portion and the second portion can be used as a pipe or a heat pipe for a cooling medium, and the heat dissipation performance of the heat dissipation portion can be further improved.

[0018] The first portion and the second portion can each also define a flow path for the cooling medium between the frame and the portion. In this case, the heat dissipation performance of the heat dissipation portion can be further improved.

[0019] The X-ray module according to one aspect of the present disclosure can also include a deflection portion having a permanent magnet that deflects the electron beam by a magnetic force of the permanent magnet, and the second portion can be thermally connected to the deflection portion. In this case, the position of the X-ray focal point can be made a desired position by the deflection portion. In addition, the permanent magnet can be prevented from being heated by heat generated by the target, and the X-ray can be stably output.

[0020] Effects of the Invention

[0021] According to one aspect of the present disclosure, an X-ray module that can suppress an increase in FOD while dissipating heat generated by a target well can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 is a cross-sectional view of an X-ray generating apparatus according to an embodiment.

[0023] Fig. 2 is a cross-sectional view of an X-ray tube.

[0024] Fig. 3 is an exploded perspective view of an X-ray tube.

[0025] Fig. 4 is a cross-sectional view of a periphery of a protruding portion.

[0026] Fig. 5 is a cross-sectional view of a periphery of a target.

[0027] Fig. 6 is a cross-sectional view of an X-ray tube.

[0028] Fig. 7 is a cross-sectional view of a periphery of a deflection portion.

[0029] Fig. 8 is a cross-sectional view of an X-ray generating apparatus according to a first modified example.

[0030] Fig. 9 is a cross-sectional view of an X-ray generating apparatus according to a second modified example. DETAILED DESCRIPTION

[0031] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference signs, and overlapping description is omitted.

[0032] [X-ray generating apparatus]

[0033] Fig. 1 The illustrated X-ray generating apparatus (X-ray module) 100 is, for example, a minute focal point X-ray source used in X-ray non-destructive inspection for observing the internal structure of an inspection object. The X-ray generating apparatus 100 is provided with an X-ray tube 1, a heat dissipation portion 7, a housing 110, and a power supply portion 120.

[0034] As Fig. 2 illustrated, the X-ray tube 1 is a transmission type X-ray tube that causes X-rays XR generated by the incidence of an electron beam B from an electron gun 3 to a target 4 and that transmits the X-rays XR themselves to be emitted from an X-ray emission window 5 in a direction along the incidence direction of the electron beam B. The X-ray tube 1 is a vacuum-sealed type X-ray tube that does not need a frame 2 having an internal space R in a vacuum, and that does not need component replacement or the like. Hereinafter, a direction parallel to a tube axis AX of the X-ray tube 1 is referred to as an axial direction A, one side (the upper side in the drawing) in the axial direction A is referred to as a first side S1, and the other side (the side opposite to the first side S1) in the axial direction A is referred to as a second side S2. In the X-ray tube 1, the optical axis of the electron beam B coincides with the optical axis of the X-rays XR.

[0035] The frame 2 has a substantially cylindrical outer shape. The frame 2 has a head portion 21 formed of a metal material and an insulating vacuum tube 22 formed of an insulating material such as glass. The target 4 and the X-ray emission window 5 are fixed to the head portion 21.

[0036] The electron gun 3 is fixed to the insulating vacuum tube 22. The electron gun 3 emits an electron beam B to the internal space R. The electron gun 3 is configured by, for example, a heater 31, a cathode 32, a first grid electrode 33, and a second grid electrode 34 arranged in this order from the second side S2. The heater 31 is configured by a filament that generates heat by electric conduction. The cathode 32 is heated by the heater 31 to emit electrons. The first grid electrode 33 and the second grid electrode 34 are formed in a cylindrical shape. The first grid electrode 33 is provided to control the amount of electrons emitted from the cathode 32, and the second grid electrode 34 is provided to focus the electrons that have passed through the first grid electrode 33 toward the target 4. The heater 31, the cathode 32, the first grid electrode 33, and the second grid electrode 34 are electrically connected to a plurality of sewing needles SP provided so as to penetrate the bottom portion 22a of the insulating vacuum tube 22.

[0037] The housing 110 includes a cylindrical component 111 and a power supply housing 112. The housing 110 is made of a metallic material. The cylindrical component 111 is formed into a generally cylindrical shape and has openings 111a and 111b at both ends in the axial direction A. An X-ray tube 1 is inserted into the opening 111a with its head 21 protruding from the opening 111a. A mounting flange 23c of the X-ray tube 1 is fixed to the end of the first side S1 of the cylindrical component 111. Thus, the X-ray tube 1 seals the opening 111a. Insulating oil K, which is a liquid insulating material, is sealed inside the cylindrical component 111.

[0038] The power supply unit 120 supplies power to the X-ray tube 1. The power supply unit 120 is housed within a power supply unit housing 112. The power supply unit 120 seals the opening 111b of the cylindrical component 111. The power supply unit 120 has a high-voltage power supply unit 121 including a cylindrical connector 121a. The high-voltage power supply unit 121 is electrically connected to the X-ray tube 1. Specifically, the front end of the connector 121a is electrically connected to a suture needle SP protruding from the bottom 22a of the insulating vacuum tube 22. In this example, with the target 4 (anode) as the ground potential, a negative high voltage (e.g., -10kV to -500kV) is supplied from the power supply unit 120 to the electron gun 3 via the high-voltage power supply unit 121.

[0039] [X-ray tube]

[0040] like Figs. 1 to 7 As shown, the X-ray tube 1 includes: a frame 2, an electron gun 3, a target 4, an X-ray emission window 5, and a deflection section 6. As described above, the frame 2 has a head 21 and an insulating vacuum tube 22. The head 21 is equivalent to the anode of the X-ray tube 1 in terms of potential. The head 21 includes a main body 23 and a cover 24. The main body 23 is formed into a generally cylindrical shape coaxial with the tube axis AX, for example, from stainless steel (e.g., SUS304), copper, iron alloy, or copper alloy, and has openings 23a and 23b at both ends in the axial direction A. The opening 23a is blocked by the cover 24. The cover 24 is fixed to the edge of the opening 23a. The main body 23 communicates with the generally cylindrical insulating vacuum tube 22 coaxial with the tube axis AX at the opening 23b. A mounting flange 23c, formed as a generally annular plate concentric with the main body 23, is provided on the outer peripheral surface of the main body 23.

[0041] The cover 24 is formed, for example, from molybdenum in a generally circular plate shape coaxial with the tube axis AX, blocking the opening 23a of the main body 23. A protrusion 26 is formed on the surface 24a of the first side S1 of the cover 24, protruding toward the first side S1 relative to the surface 24a. The surface 24a is circular, and the protrusion 26 is formed as a cylinder concentric with the cover 24. An opening 27 is formed in the protrusion 26 that penetrates the cover 24 along the axial direction A.

[0042] like Figs. 4 to 6As shown, the opening portion 27 has a first portion 27a that opens at the surface 26a of the first side S1 of the protruding portion 26 and a second portion 27b that communicates with the first portion 27a and opens at the surface 24b of the second side S2 of the cover portion 24. The first and second portions 27a and 27b are each formed in a cross-sectional circular shape concentric with the protruding portion 26. The diameter of the first portion 27a is larger than that of the second portion 27b, and the depth of the first portion 27a is shallower than that of the second portion 27b. In other words, the first portion 27a is a recess formed in the surface 26a of the protruding portion 26, and the second portion 27b is a through-hole formed in the bottom surface of the first portion 27a. The first portion 27a functions as a disposition portion for disposing the target 4 and the X-ray emission window 5. The second portion 27b functions as an electron beam passing hole through which the electron beam B incident to the target 4 passes. A widened portion 27ba whose diameter widens toward the second side S2 is provided at the end of the second side S2 of the second portion 27b, and is chamfered in a curved surface shape so as not to form a corner portion.

[0043] The target 4 and the X-ray emission window 5 are disposed in the first portion 27a. The target 4 is formed of, for example, tungsten, and has an electron incidence surface 4a and an X-ray emission surface 4b on the side opposite to the electron incidence surface 4a. The target 4 transmits X-rays generated by the incidence of the electron beam B to the electron incidence surface 4a and emits the X-rays from the X-ray emission surface 4b. In this example, the target 4 is formed in a film shape on the entire surface of the surface of the second side S2 of the X-ray emission window 5. That is, the target 4 is formed in a unit with the X-ray emission window 5. The target 4 is disposed so that the electron incidence surface 4a faces the second side S2 and the X-ray emission surface 4b faces the first side S1. The thickness of the target 4 is, for example, several μm or so.

[0044] The X-ray emission window 5 is formed in a circular plate shape of, for example, a material such as diamond or beryllium having high X-ray transmittance. The X-ray emission window 5 is disposed coaxially with the tube axis AX on the bottom surface of the first portion 27a of the opening portion 27, is fixed to the bottom surface by a joining member such as a brazing material not shown, and seals the opening portion 27. The X-ray emission window 5 is in thermal contact with the bottom surface of the first portion 27a via the target 4. In this example, the surface 5a of the first side S1 of the X-ray emission window 5 is located on substantially the same plane as the surface 26a of the first side S1 of the protruding portion 26. The X-ray emission window 5 is opposed to the electron gun 3 in the axial direction A, transmits the X-rays XR emitted from the target 4, and emits the X-rays XR toward the first side S1 in the axial direction A. As shown, Fig. 5 As shown, the X-rays XR are generated in an X-ray focal point F that is an irradiation point of the electron beam B on the target 4, and are emitted while expanding with the X-ray focal point F as the center. Note that the target 4 can be provided only in a region of the surface of the X-ray emission window 5 that is exposed to the second portion 27b, or a part thereof can be provided on the wall surface of the second portion 27b. Alternatively, the target 4 can be provided separately from the X-ray emission window 5.

[0045] As shown in Fig. 2 and Fig. 7 shown, the deflection portion 6 has a plurality of permanent magnets 61, a holding member 62, and a heat insulating member 63. The deflection portion 6 includes a pair of permanent magnets 61 facing each other in the radial direction. The pair of permanent magnets 61 are arranged so as to face each other in the radial direction with different poles. The permanent magnets 61 are composed of, for example, ferrite magnets, neodymium magnets, samarium-cobalt magnets, alnico magnets, or the like.

[0046] The holding member 62 is formed in a flat cylindrical shape (annular shape) coaxial with the pipe axis AX, for example, from a metal material such as aluminum, and holds the permanent magnets 61. The holding member 62 is arranged outside the frame body 2, and is fixed to the mounting flange 23c of the main body portion 23 in a state of contacting the surface of the first side S1 of the mounting flange 23c. The holding member 62 overlaps a part of the main body portion 23 in the radial direction, and is arranged close to the main body portion 23 in a manner of covering the outer peripheral surface of a part of the main body portion 23. The holding member 62 is slightly separated from the main body portion 23 in the radial direction, but can also be in contact with the main body portion 23. In addition, the holding member 62 can not be a unitary member in a cylindrical shape (annular shape), but can be composed of a plurality of members.

[0047] The heat insulating member 63 is formed of, for example, a resin material such as silicone resin, epoxy resin, acrylic resin, polyimide resin, polyphenylene sulfide (PPS) resin, polyether ether ketone (PEEK) resin, or the like. As the material of the heat insulating member 63, in order to suppress a decrease in the magnetic force of the permanent magnets 61 due to a heating process at the time of curing the heat insulating member 63, silicone resin, epoxy resin, and acrylic resin having a room temperature curing property are preferable.

[0048] The heat insulating member 63 houses the permanent magnets 61 inside. That is, the permanent magnets 61 are arranged inside the heat insulating member 63 in a state of being surrounded by the heat insulating member 63. The heat insulating member 63 is fixed to the holding member 62, for example, and the holding member 62 holds the permanent magnets 61 via the heat insulating member 63. The heat insulating member 63 separates the permanent magnets 61 from the holding member 62. The surface 63a of the second side S2 of the heat insulating member 63 is in contact with the surface of the first side S1 of the mounting flange 23c of the main body portion 23. The outer surface of the heat insulating member 63 other than the surface 63a is covered by the holding member 62. That is, the heat insulating member 63 is provided in a manner of being buried in the holding member 62 so as to expose only the surface 63a. In this way, the heat insulating member 63 has a portion arranged between the permanent magnets 61 and the mounting flange 23c of the main body portion 23. Note that the structure of the heat insulating member 63 is not limited to the structure of housing the permanent magnets 61 inside, and can be, for example, a structure of sandwiching the heat insulating member 63 in a plate shape in a manner of separating the holding member 62 from the surface of the first side S1 of the mounting flange 23c of the main body portion 23 while directly holding the permanent magnets 61 by the holding member 62.

[0049] The deflector 6 deflects the electron beam B using the magnetic force of the permanent magnet 61, thereby changing the position of the X-ray focus F. When viewed radially from a direction perpendicular to the path P of the electron beam B emitted from the electron gun 3 towards the target 4, the deflector 6 includes a portion overlapping the path P. This allows the magnetic force of the permanent magnet 61 to be appropriately applied to the electron beam B. In this example, when viewed radially, the entire deflector 6 overlaps with the path P. The deflector 6 is mounted on the mounting flange 23c such that the imaginary line connecting the opposing pair of permanent magnets 61 is approximately orthogonal to the tube axis AX. The deflector 6 can also rotate about the tube axis AX. In this case, by rotating the deflector 6, the position of the X-ray focus F can be moved.

[0050] The thermal conductivity of the retaining component 62 is higher than that of the permanent magnet 61. The thermal conductivity of the heat-insulating component 63 is lower than that of the main body 23 of the frame 2 (the part in contact with the deflection portion 6 in the frame 2). That is, the heat insulation performance of the heat-insulating component 63 is higher than that of the main body 23. In addition, the thermal conductivity of the heat-insulating component 63 is lower than that of both the permanent magnet 61 and the retaining component 62. When the main body 23 is formed of SUS304, the thermal conductivity of the main body 23 is, for example, 16.7 W / m·K. The thermal conductivity of the permanent magnet 61 is, for example, about 1 to 50 W / m·K, the thermal conductivity of the retaining component 62 is, for example, about 100 to 400 W / m·K, and the thermal conductivity of the heat-insulating component 63 is, for example, about 0.1 to 0.5 W / m·K. Thermal conductivity can be measured by general measurement methods, such as heat flow metering, laser flash method, hot wire method, etc.

[0051] like Fig. 1 , Fig. 3 , Fig. 4 as well as Fig. 6 As shown, the heat dissipation section 7 includes a heat sink 70 for dissipating heat generated by the target 4 and a cooling section 80 for cooling the heat sink 70, and is disposed outside the frame 2. The heat sink 70 is formed of a metal material such as aluminum. The thermal conductivity of the heat sink 70 is higher than that of the main body 23 and the permanent magnet 61. The thermal conductivity of the heat sink 70 is, for example, about 100 to 400 W / m·K. The heat sink 70 has a first part 71 and a second part 72.

[0052] The first portion 71 is formed as a circular plate coaxial with the tube shaft AX, and has an opening 71b in the center. The first portion 71 extends perpendicularly to the tube shaft AX along the surface 24a of the cover portion 24, and a protrusion 26 is disposed within the opening 71b. The first portion 71 surrounds the protrusion 26 when viewed from the axial direction A. The surface of the second side S2 of the first portion 71 contacts the surface 24a of the cover portion 24 via a sheet-like heat-conducting member 8. Thus, the first portion 71 is thermally connected to the surface 24a of the cover portion 24. The heat-conducting member 8 is, for example, a circular sheet of silicone resin with high thermal conductivity, disposed between the entire surface of the surface 24a and the first portion 71, and is in close contact with both the surface 24a and the first portion 71. By having the heat-conducting member 8 between the first portion 71 and the cover portion 24, compared to the case where the first portion 71, which is made of metal material, is in direct contact with the cover portion 24, heat conduction between the first portion 71 and the cover portion 24 can be promoted.

[0053] like Fig. 4 As shown, the first portion 71 is slightly separated from the protrusion 26 in the radial direction. The radial distance L1 between the first portion 71 and the protrusion 26 is smaller than the protrusion height L2 of the protrusion 26 protruding from the surface 24a of the cover portion 24 in the axial direction A, and also smaller than the diameter (radial width of the protrusion 26) L3 of the protrusion 26. The first portion 71 may also contact the protrusion 26. The first portion 71 does not protrude toward the first side S1 relative to the protrusion 26. In other words, when the surface 71a of the first side S1 of the first portion 71 and the surface 26a of the first side S1 of the protrusion 26 are flat, the surface 71a is located on the same plane as the surface 26a, or at a position closer to the second side S2 than the surface 26a. In this example, the surface 71a is located on the same plane as the surface 26a. In addition, the surface 71a is located on the same plane as the surface 5a of the first side S1 of the X-ray exit window 5.

[0054] The second part 72 is formed as a generally cylindrical shape concentric with the first part 71, extending from the outer edge of the first part 71 toward the second side S2. Viewed from the axial direction A, the second part 72 is located outside the outer edge of the surface 24a of the cover part 24, and in the axial direction A, it is located on the second side S2 of the surface 24a. In this example, the entire second part 72 is located on the second side S2 of the surface 24a, but only a portion of the second part 72 may be located on the second side S2 of the surface 24a. The second part 72 overlaps radially with a portion of the main body part 23 and covers the outer peripheral surface of a portion of the main body part 23. The second part 72 is slightly separated radially from the main body part 23, but it may also contact the main body part 23. The surface 72b of the second side S2 of the second part 72 contacts the surface of the first side S1 of the retaining member 62 of the deflection part 6, and is thermally connected to the deflection part 6.

[0055] A plurality of fins 72a are formed on the outer peripheral surface of the second portion 72. Each fin 72a is formed in a substantially circular plate shape concentric with the second portion 72. The plurality of fins 72a are arranged in parallel with each other in a manner of being arranged at equal intervals along the axial direction A. Air from a cooling fan 84 described later is supplied to the fins 72a.

[0056] The cooling portion 80 includes a blow portion 81 and an encasing portion 82 formed in a substantially cylindrical shape so as to encase the heat sink 70. The blow portion 81 includes a cover portion 83 and the cooling fan 84. The cover portion 83 covers one side of a cylindrical member 111 in a direction perpendicular to the axial direction A, and forms a space 83a. The cooling fan 84 is arranged in the space 83a. A plurality of through holes are formed in the cover portion 83 as air inlets 83b. The cooling fan 84 sends outside air sucked from the air inlets 83b into the encasing portion 82 as cooling air.

[0057] The encasing portion 82 has an upper wall portion 82a and a side wall portion 82b. The upper wall portion 82a is formed in a circular ring shape, and defines an opening 82c of the first side S1 of the encasing portion 82. The encasing portion 82 is arranged so that the surface 71a of the first side S1 of the first portion 71 is exposed from the opening 82c. The side wall portion 82b is formed in a cylindrical shape, and encases the plurality of fins 72a together with the upper wall portion 82a. The encasing portion 82 constitutes a flow path through which cooling air sent from a communication portion between the blow portion 81 and the encasing portion 82 flows in a circumferential direction in a space between the plurality of fins 72a. Thereby, it is possible to improve the heat dissipation efficiency of the heat sink 70. Further, the cooling air is discharged from an air inlet (not shown) provided in the side wall portion 82b. Thereby, it is possible to make it difficult for the cooling air after the discharge to flow toward the inspection object side, and it is possible to suppress the influence of the discharge at the time of imaging. In addition, the cooling fan 84 can also operate in a manner of sucking outside air from the air inlet provided in the side wall portion 82b and discharging it from the air inlets 83b provided in the cover portion 83.

[0058] [Effects]

[0059] In the X-ray generating apparatus 100, the target 4 has an electron incidence surface 4a and an X-ray emission surface 4b, and X-rays XR generated by incidence of the electron beam B to the electron incidence surface 4a are transmitted and emitted from the X-ray emission surface 4b. In such a transmission type structure, compared with a reflection type structure in which the electron incidence surface serves also as the X-ray emission surface, the target 4 can be easily arranged in the vicinity of the X-ray emission window 5, and the FOD can be reduced. In addition, the protruding portion 26 protruding toward the first side S1 is formed on the surface 24a of the frame 2, and the target 4 is arranged in the opening portion 27 formed in the protruding portion 26. Thus, the FOD can be further reduced. Further, the heat sink 70 has a first portion 71 extending along the surface 24a and thermally connected to the surface 24a. Thus, the heat sink 70 can be arranged using the space of the height of the protruding portion 26, the FOD can be suppressed from becoming large, and the heat generated by the target 4 can be efficiently dissipated. Further, the heat sink 70 has a second portion 72 extending from the first portion 71 toward a second side S2 opposite to the first side S1. Thus, the FOD can be suppressed from becoming large, and the heat dissipation of the heat sink 70 can be improved. Thus, according to the X-ray generating apparatus 100, the FOD can be suppressed from becoming large, and the heat generated by the target 4 can be efficiently dissipated.

[0060] Reference Signs List Figs. 4 to 6 The movement path of the heat is described. As described above, a large amount of heat can be generated in the target 4. In the X-ray generating apparatus 100, as shown by an arrow in FIG. 6, the heat generated by the target 4 is transferred from the protruding portion 26 of the frame 2 to the cover portion 24. The heat transferred to the cover portion 24 is transferred to the first portion 71 of the heat sink 70 via the heat conductive member 8. The heat transferred to the first portion 71 is transferred to the second portion 72. Thus, the heat generated by the target 4 can be efficiently dissipated using the heat sink 70. In addition, since the thickness is increased by the protruding portion 26, the heat capacity in the region thermally connected to the target 4 can be increased. Figs. 4 to 6

[0061] Here, it is assumed that, in the case where the protruding portion 26 is not provided, the target 4 is arranged close to the second side S2, and the FOD is increased by an amount corresponding to the thickness of the first portion 71 of the heat sink 70, and thus the advantages of the transmission type X-ray tube can be impaired. In this case, if the first portion 71 of the heat sink 70 is omitted, the FOD can be suppressed from becoming large, but the heat generated by the target 4 cannot be efficiently dissipated. Thus, by providing the protruding portion 26, the position of the target 4 is brought close to the examination object, and the heat sink 70 is arranged using the space of the height, which is very effective for suppressing the FOD from becoming large and for efficiently dissipating the heat generated by the target 4.

[0062] ​Further, if the heat sink 70 protrudes more toward the first side S1 than the surface 26a of the first side S1 of the protruding portion 26, the FOD becomes large, and it is possible that the advantages of the transmission type X-ray tube are impaired. This is because the examination object comes into contact with the heat sink 70, and the examination object cannot approach the X-ray focal point F. In contrast, in the X-ray generating apparatus 100, the heat sink 70 does not protrude toward the first side S1 with respect to the protruding portion 26. Thus, it is possible to further reduce the FOD. Further, the surface 71a of the first side S1 of the first portion 71 of the heat sink 70 is located on the same plane as the surface 26a of the first side S1 of the protruding portion 26. Thus, it is possible to suppress the FOD from becoming large, and it is possible to secure the thickness of the first portion 71 and improve the heat dissipation of the heat dissipation portion 7. Further, by shortening the distance from the heat generating portion (X-ray focal point F) to the first portion 71, it is also possible to improve the heat dissipation of the heat sink 70.

[0063] The second portion 72 is located at a position that is located outward of the outer edge of the surface 24a of the frame 2 when viewed in the axial direction A, and is located at a position that is located on the second side S2 with respect to the surface 24a in the axial direction A. Thus, it is possible to suppress an increase in the FOD, and improve the heat dissipation of the heat sink 70.

[0064] The first portion 71 surrounds the protruding portion 26 when viewed in the axial direction A. Thus, it is possible to more effectively dissipate heat generated by the target 4.

[0065] The surface 5a of the first side S1 of the X-ray emission window 5 is located on the same plane as the surface 71a of the first side S1 of the first portion 71. Thus, it is possible to further reduce the FOD.

[0066] The thermally conductive member 8 is disposed between the first portion 71 and the surface 24a of the frame 2. Thus, it is possible to more effectively dissipate heat generated by the target 4.

[0067] The second portion 72 includes a plurality of fins 72a. Thus, it is possible to further improve the heat dissipation of the heat dissipation portion 7.

[0068] The deflection section 6 deflects the electron beam B by the magnetic force of the permanent magnet 61. The second section 72 is thermally connected to the deflection section 6. Thus, the position of the X-ray focus F can be moved to a desired position by the deflection section 6. In addition, when heat generated at the target 4 is transferred to the permanent magnet 61, the permanent magnet 61 is heated, and the magnetic force can be reduced. In this case, the deflection amount of the electron beam B changes, and the position of the X-ray focus changes. For example, when continuous photography is performed in CT (Computed Tomography) or the like, if the position of the X-ray focus changes, blurring can occur in the obtained image. In contrast, in the X-ray generating apparatus 100, even when heat generated at the target 4 is transferred to the deflection section 6, the heat can be released to the heat dissipation section 7. As a result, the permanent magnet 61 can be prevented from being heated by heat generated at the target 4, and the X-ray can be stably output.

[0069] [Modified Example]

[0070] In Fig. 8 In the first modified example shown in FIG. 9, the first section 71A and the second section 72A of the heat dissipation section 7 are formed in a tubular shape. The first section 71A extends in a straight line shape perpendicular to the tube axis AX along the surface 24a of the cover section 24, and is thermally connected to the surface 24a. Note that the first section 71A can be arranged in a manner that a circular ring shape (vortex shape) or a straight line section is folded back at the surface 24a of the cover section 24. In this case, the thermal connection area can be further increased. The second section 72A extends from the first section 71A toward the second side S2. In this example, the first section 71A and the second section 72A constitute a heat pipe, and working fluid is enclosed in the inside.

[0071] In the first modified example, the cooling fan 84 is arranged in the power supply section housing 112. The second section 72A extends to the vicinity of the cooling fan 84 in a manner that the facing section 72Aa faces the cooling fan 84. The cooling fan 84 also functions to cool the control substrate 130 arranged in the power supply section housing 112. That is, in the first modified example, the cooling fan for dissipating heat generated by the target 4 and the cooling fan for cooling the control substrate 130 are common. Thus, low cost can be achieved. In addition, since the cooling fan 84 is arranged at a position away from the target 4 (X-ray tube 1), failure of the cooling fan 84 due to X-ray irradiation can be suppressed. The control substrate 130 controls the operation of the power supply section 120, for example. The control substrate 130 faces the facing section 72Aa.

[0072] According to the first variation, similarly to the embodiment described above, it is possible to suppress the increase of FOD and to effectively dissipate heat generated at the target 4. Furthermore, since the first portion 71A and the second portion 72A are formed in a tubular shape, they can be used as heat pipes or the like, thereby improving the heat dissipation performance of the heat dissipation section 7. Additionally, since long-distance heat transfer is possible, as described above, the cooling fan 84 can be positioned away from the target 4.

[0073] It can also be like Fig. 9 The heat dissipation section 7 is configured as shown in the second variation. In the second variation, the first part 71B and the second part 72B of the heat dissipation section 7 include components 71Ba and 72Ba that define flow paths 73 and 74 between the heat dissipation section 7 and the frame 2 for the flow of the cooling medium C. Component 71Ba is formed as an annular plate coaxial with the tube axis AX, and an annular flow path 73 coaxial with the tube axis AX is defined between the heat dissipation section 71Ba and the surface 24a of the cover 24. The first part 71B is composed of component 71Ba and flow path 73. The first part 71B extends along the surface 24a of the cover 24 and is thermally connected to the surface 24a. The second part 72B is formed as a cylinder concentric with the first part 71B, and a cylindrical flow path 74 concentric with the first part 71B is defined between the second part 72B and the outer peripheral surface of the main body 23. The second part 72B is composed of component 72Ba and flow path 74. The second part 72B extends from the first part 71B along the axial direction A toward the second side S2.

[0074] According to the second variation, similarly to the above embodiment, it is possible to suppress the increase of FOD and to effectively dissipate the heat generated by the target 4. In addition, since the first part 71B and the second part 72B are respectively defined with flow paths 73 and 74 between themselves and the frame 2 for the flow of the cooling medium C, the heat dissipation performance of the heat dissipation part 7 can be further improved.

[0075] The present disclosure is not limited to the above-described embodiments. The materials and shapes of the structures are not limited to those described above, and various materials and shapes can be employed. The first portion 71 can not surround the protrusion 26 when viewed from the axial direction A, and can be formed in a shape other than a ring shape. The heat sink 70 can also protrude more toward the first side S1 than the surface 26a of the first side S1 of the protrusion 26. The deflector 6 can also be omitted. The thermally conductive member 8 can also be omitted. In the above-described embodiments, forced air cooling is performed using the cooling fan 84, but natural air cooling can also be performed with the cooling fan 84 omitted. The cooling fan 84 can also be provided adjacent to the fin 72a. The heat dissipation portion 7 can also be a cooling mechanism other than the above-described examples. In the first modified example, the first portion 71A and the second portion 72A can also constitute a cooling water pipe for flowing cooling water. In this case, the heat dissipation of the heat dissipation portion 7 can also be improved as in the first modified example. In addition, at least a portion of the deflector 6 and the heat dissipation portion 7 can also be integrated with the X-ray tube 1. In the above-described embodiments, the X-ray module constitutes the X-ray generating apparatus 100, but the X-ray module can also not necessarily constitute the X-ray generating apparatus, and for example, can only be provided with the X-ray tube 1 and the heat dissipation portion 7 (heat sink 70).

Claims

1. An X-ray module characterized by comprising a vacuum-sealed X-ray tube and a heat dissipation portion, the vacuum-sealed X-ray tube has: a frame having an internal space in vacuum and formed with an opening portion; an electron gun that emits an electron beam inside the frame; a target that has an electron incidence surface and an X-ray emission surface on the side opposite to the electron incidence surface, and that emits X-rays generated by incidence of the electron beam to the electron incidence surface, through the X-ray emission surface; and an X-ray emission window that seals the opening portion and emits the X-rays emitted from the target to a first side in an axial direction through the X-ray emission window, the heat dissipation portion is disposed outside the frame, the frame has a surface formed with a protruding portion protruding to the first side, the opening portion is formed in the protruding portion, and the target is disposed inside the opening portion, the heat dissipation portion has: a first portion extending along the surface and thermally connected to the surface; and a second portion extending from the first portion to a second side opposite to the first side. the second portion is located outward of an outer edge of the surface when viewed from the axial direction and is located closer to the second side than the surface in the axial direction.

2. The X-ray module of claim 1, characterized in that the first portion surrounds the protruding portion when viewed from the axial direction.

3. The X-ray module of claim 1, characterized in that the first portion surrounds the protruding portion when viewed from the axial direction.

4. The X-ray module of claim 2, characterized in that the heat dissipation portion does not protrude to the first side with respect to the protruding portion.

5. The X-ray module of claim 1, wherein, the heat dissipation portion does not protrude to the first side with respect to the protruding portion.

6. The X-ray module of claim 2, wherein, the heat dissipation portion does not protrude to the first side with respect to the protruding portion.

7. The X-ray module of claim 3, wherein, the heat dissipation portion does not protrude to the first side with respect to the protruding portion.

8. The X-ray module of claim 4, characterized in that a surface of the first side of the heat dissipation portion is located on the same plane as a surface of the first side of the protruding portion.

9. The X-ray module according to any one of claims 1 to 8, characterized in that, a surface of the first side of the X-ray emission window is located on the same plane as a surface of the first side of the heat dissipation portion.

10. The X-ray module according to any one of claims 1 to 8, characterized in that, a surface of the first side of the X-ray emission window is located on the same plane as a surface of the first side of the heat dissipation portion.

11. The X-ray module of claim 9, characterized in that a thermally conductive member disposed between the first portion and the surface is further included.

12. The X-ray module according to any one of claims 1 to 8, characterized in that, the second portion includes a plurality of fins.

13. The X-ray module according to any one of claims 1 to 8, characterized in that, the first portion and the second portion are formed in a tubular shape.

14. The X-ray module according to any one of claims 1 to 8, characterized in that, the first portion and the second portion respectively include a member that defines a flow path for a cooling medium to flow between the frame and the member.

15. The X-ray module according to any one of claims 1 to 8, characterized in that, a deflection portion having a permanent magnet that deflects the electron beam by a magnetic force of the permanent magnet is further included, 16. The X-ray module according to any one of claims 1 to 8, characterized in that, the second portion is thermally connected to the deflection portion. ​

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