X-ray module

Abstract

The X-ray module of the present application includes a housing, an electron gun that emits an electron beam inside the housing, a target that is disposed inside the housing and fixed to the housing and generates X-rays due to the incidence of the electron beam, and a deflection unit having a permanent magnet, which is disposed outside the housing, and deflects the electron beam using the magnetic force of the permanent magnet. The deflection unit has a heat insulating member disposed at least between the permanent magnet and the housing, and the thermal conductivity of the heat insulating member is lower than the thermal conductivity of the permanent magnet.

Description

Technical Field

[0001] One aspect of this disclosure relates to an X-ray module. Background Technology

[0002] Known X-ray modules include: a cathode irradiating an electron beam; a target that generates X-rays by being irradiated by the electron beam; and a magnet that uses the magnetic field of a permanent magnet to move the irradiation position of the electron beam irradiating the target (see, for example, Japanese Patent Application Publication No. 2004-265602). In the X-ray module described in Patent Document 1, the irradiation position can be adjusted even if the target deteriorates at the current irradiation position, thus extending the target's lifespan. Summary of the Invention The technical problem that the invention aims to solve

[0003] In an X-ray module like the one described above, the conversion efficiency of the electron beam into X-rays within the target is approximately 1%, and about 99% of the incident electron beam becomes heat, potentially generating a significant amount of heat on the target. When this heat is transferred to the permanent magnet, it is heated, causing the magnetic force to decrease. In this situation, the deflection of the electron beam changes, and the position of the X-ray focus (the point on the target where the electron beam irradiates) changes. For example, if the position of the X-ray focus changes during continuous imaging such as CT (Computed Tomography), it can lead to blurring in the acquired image.

[0004] Therefore, one aspect of the present invention is to provide an X-ray module capable of stably outputting X-rays. Technical means for solving technical problems

[0005] One aspect of the X-ray module disclosed herein includes: a housing; an electron gun that emits an electron beam from the housing; a target disposed within and fixed to the housing, which generates X-rays due to the incident electron beam; and a deflection section having a permanent magnet disposed outside the housing, which deflects the electron beam by the magnetic force of the permanent magnet, the deflection section having at least a heat-insulating member disposed between the permanent magnet and the housing, the heat-insulating member having a lower thermal conductivity than the permanent magnet.

[0006] In this X-ray module, the deflection section has at least one heat-insulating component disposed between the permanent magnet and the housing, the heat-insulating component having a lower thermal conductivity than the permanent magnet. Therefore, even if heat generated on the target is transferred to the deflection section, the heat-insulating component can suppress this heat transfer to the permanent magnet, thereby preventing the permanent magnet from being heated by heat generated on the target. Thus, according to this X-ray module, X-rays can be output stably.

[0007] Alternatively, the thermal conductivity of the insulation component can be lower than that of the contact portion of the housing that contacts the deflector. In this case, even if heat generated on the target is transferred to the deflector via the housing, the insulation component can be used to suppress the heat transfer to the permanent magnet.

[0008] Alternatively, the heat insulation component may house the permanent magnet internally. In this case, the heat generated on the target can be effectively suppressed from being transferred to the permanent magnet.

[0009] Alternatively, the heat insulation component can extend in a way that separates the permanent magnet from the housing. In this case, the heat generated on the target can be effectively suppressed from being transferred to the permanent magnet.

[0010] Alternatively, the deflection section may also include a holding member for holding the permanent magnet, the holding member having a higher thermal conductivity than the permanent magnet. In this case, the heat transferred to the deflection section can be dissipated to the holding member.

[0011] Alternatively, a heat-insulating component can be used to separate the permanent magnet from the retaining component. In this case, heat transfer from the retaining component to the permanent magnet can be suppressed.

[0012] Alternatively, when viewed in a direction perpendicular to the path of the electron beam emitted from the electron gun towards the target, the deflector may include a portion overlapping the path. In this case, the electron beam can be effectively deflected using the deflector.

[0013] Alternatively, the X-ray module of one aspect of the present invention may also include a heat dissipation unit having a higher thermal conductivity than that of the permanent magnet, and is thermally connected to the deflection unit. In this case, heat transferred to the deflection unit can be dissipated to the heat dissipation unit.

[0014] Alternatively, the heat sink may include multiple fins. In this case, the heat dissipation performance of the heat sink can be improved.

[0015] Alternatively, the heat dissipation section can be formed into a tubular shape. In this case, the heat dissipation performance of the heat dissipation section can be improved. The effects of the invention

[0016] According to one aspect of the present invention, an X-ray module capable of stably outputting X-rays can be provided. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the X-ray generating apparatus according to the embodiment.

[0018] Figure 2 This is a cross-sectional view of an X-ray tube.

[0019] Figure 3 This is an exploded 3D view of an X-ray tube.

[0020] Figure 4It is a cross-sectional view showing the periphery of the protrusion.

[0021] Figure 5 It is a cross-sectional view showing the perimeter of the target.

[0022] Figure 6 This is a cross-sectional view of an X-ray tube.

[0023] Figure 7 It is a cross-sectional view showing the periphery of the deflection section.

[0024] Figure 8 This is a cross-sectional view of the X-ray generating device of the first modified example.

[0025] Figure 9 This is a cross-sectional view of the X-ray generating device in the second modified example. Detailed Implementation

[0026] Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are referred to by the same reference numerals, and repeated descriptions are omitted. [X-ray generating device]

[0027] Figure 1 The X-ray generating apparatus (X-ray module) 100 shown is, for example, a small-focus X-ray source used in non-destructive X-ray examinations to observe the internal structure of an object. The X-ray generating apparatus 100 includes an X-ray tube 1, a heat sink 7, a housing 110, and a power supply 120.

[0028] like Figure 2 As shown, X-ray tube 1 is a transmission-type X-ray tube in which X-rays XR generated by incident an electron beam B from electron gun 3 onto target 4 and passing through target 4 are emitted from X-ray exit window 5 in the direction of incident of electron beam B. X-ray tube 1 is a vacuum-sealed X-ray tube including housing 2, which does not require component replacement, etc., wherein housing 2 has a vacuum internal space R. Hereinafter, the direction parallel to the tube axis AX of X-ray tube 1 is defined as axial direction A, one side of axial direction A (the upper side in the figure) is defined as side 1 S1, and the other side of axial direction A (the opposite side of side 1 S1) is defined as side 2 S2. In X-ray tube 1, the optical axis of electron beam B is aligned with the optical axis of X-ray XR.

[0029] The housing 2 has a generally cylindrical shape. The housing 2 has: a head 21 made of metal; and an insulating vacuum tube 22 made of insulating material such as glass. The target 4 and the X-ray exit window 5 are fixed in the head 21.

[0030] The electron gun 3 is fixed to the insulating vacuum tube 22. Electron gun 3 emits an electron beam B from its internal space R. Electron gun 3 is configured, for example, by a heater 31, a cathode 32, a first grid electrode 33, and a second grid electrode 34 arranged sequentially from the second side S2. The heater 31 is composed of a heating wire that heats up when energized. The cathode 32 is heated by the heater 31 and releases 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 released from the cathode 32, and the second grid electrode 34 is provided to cause the electrons passing through the first grid electrode 33 to converge toward the target 4. The heater 31, cathode 32, first grid electrode 33, and second grid electrode 34 are electrically connected to a plurality of stem pins (SP) arranged to penetrate the bottom 22a of the insulating vacuum tube 22.

[0031] 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 generally cylindrical and has openings 111a and 111b at both ends in the axial direction A. The X-ray tube 1 is inserted into the opening 111a with its head 21 extending from the opening 111a. The 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.

[0032] 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 section 121 including a cylindrical connector 121a. The high-voltage power supply section 121 is electrically connected to the X-ray tube 1. Specifically, the front end of the connector 121a is electrically connected to a rod pin SP extending from the bottom 22a of the insulating vacuum tube 22. In this example, with the target 4 (anode) at 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 section 121. [X-ray tube]

[0033] like Figures 1 to 7As shown, the X-ray tube 1 includes a housing 2, an electron gun 3, a target 4, an X-ray exit window 5, and a deflection section 6. As described above, the housing 2 has a head 21 and an insulating vacuum tube 22. The head 21 corresponds 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. On the outer peripheral surface of the main body 23, a generally annular mounting flange 23c formed concentrically with the main body 23 is provided.

[0034] The cover 24 is formed, for example, from molybdenum into 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 cover 24 on the first side S1, protruding towards 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, penetrating the cover 24 along the axial direction A.

[0035] like Figures 4-6 As shown, the opening 27 has: a first portion 27a opening on the surface 26a of the first side S1 of the protrusion 26; and a second portion 27b communicating with the first portion 27a and opening on the surface 24b of the second side S2 of the cover 24. The first portion 27a and the second portion 27b are each formed as a circular cross-section concentric with the protrusion 26. The diameter of the first portion 27a is larger than the diameter of the second portion 27b, and the depth of the first portion 27a is smaller than the depth of the second portion 27b. In other words, the first portion 27a is a recess formed on the surface 26a of the protrusion 26, and the second portion 27b is a through hole formed on the bottom surface of the first portion 27a. The first portion 27a functions as a configuration portion for arranging the target 4 and the X-ray exit window 5. The second portion 27b functions as an electron beam passage hole through which the electron beam B incident on the target 4 passes. At the end of the second side S2 of the second part 27b, a widening part 27ba is provided that increases in diameter as it moves toward the second side S2, and is chamfered into a curved surface in a manner that does not form a corner.

[0036] The target 4 and the X-ray exit window 5 are disposed in part 1, 27a. The target 4 is formed of tungsten, for example, and has an electron incident surface 4a and an X-ray exit surface 4b opposite to the electron incident surface 4a. The target 4 transmits X-rays generated by the electron beam B incident on the electron incident surface 4a and exits from the X-ray exit surface 4b. In this example, the target 4 is formed as a film on the entire surface of the second side S2 of the X-ray exit window 5. That is, the target 4 is integrally formed with the X-ray exit window 5. The target 4 is disposed such that the electron incident surface 4a faces the second side S2 and the X-ray exit surface 4b faces the first side S1. The thickness of the target 4 is, for example, about a few μm.

[0037] The X-ray exit window 5 is formed into a circular plate shape, for example, from a material with high X-ray transmittance, such as diamond or beryllium. The X-ray exit window 5 is coaxially disposed on the bottom surface of the first portion 27a of the opening 27 with the tube axis AX, and is fixed to this bottom surface using a bonding component such as solder (not shown), sealing the opening 27. The X-ray exit window 5 is in thermal contact with the bottom surface of the first portion 27a through the target 4. In this example, the surface 5a of the first side S1 of the X-ray exit window 5 is located on a plane substantially the same as the surface 26a of the first side S1 of the protrusion 26. The X-ray exit window 5 is opposite to the electron gun 3 in the axial direction A, allowing X-rays XR emitted from the target 4 to be transmitted and exited towards the first side S1 in the axial direction A. Figure 5 As shown, X-rays XR are generated at the X-ray focus F on the target 4, which serves as the irradiation point of the electron beam B, and are emitted while expanding outward from the X-ray focus F. The target 4 may be disposed only in the area exposed in the second part 27b on the surface of the X-ray exit window 5, or a portion of it may also be disposed on the wall surface of the second part 27b. Furthermore, the target 4 and the X-ray exit window 5 may be disposed at intervals.

[0038] like Figure 2 and Figure 7 As shown, the deflection section 6 includes a plurality of permanent magnets 61, a holding member 62, and a heat insulation member 63. The deflection section 6 includes a pair of permanent magnets 61 facing each other in the radial direction. The pair of permanent magnets 61 are arranged such that their different poles face each other in the radial direction. The permanent magnets 61 are formed, for example, ferrite magnets, neodymium magnets, samarium cobalt magnets, AlNiCo alloy magnets, etc.

[0039] The retaining member 62 is formed from a metal material such as aluminum into a flat cylindrical (ring-shaped) form coaxial with the tube axis AX, and retains the permanent magnet 61. Furthermore, the thermal conductivity of the retaining member 62 is higher than that of the permanent magnet 61, and the retaining member 62 can also serve as part of the heat dissipation section 7. The retaining member 62 is disposed on the outside of the housing 2 and is fixed to the mounting flange 23c in contact with the surface of the first side S1 of the mounting flange 23c of the main body 23. The retaining member 62 overlaps with a portion of the main body 23 in the radial direction and is disposed close to the main body 23 in a manner that covers the outer peripheral surface of a portion of the main body 23. The retaining member 62 is slightly spaced from the main body 23 in the radial direction, but it can also contact the main body 23. The retaining member 62 may not be a single cylindrical (ring-shaped) component, but may be composed of multiple components.

[0040] The heat insulation component 63 is formed of resin materials such as silicone resin, epoxy resin, acrylic resin, polyimide resin, polyphenylene sulfide (PPS) resin, and polyetherketone resin (PEEK). As the material of the heat insulation component 63, in order to suppress the decrease in magnetic force of the permanent magnet 61 caused by the heat treatment during the hardening of the heat insulation component 63, silicone resin, epoxy resin, and acrylic resin with room temperature curing properties are preferred.

[0041] The heat insulation member 63 houses the permanent magnet 61 internally. That is, the permanent magnet 61 is arranged such that it is surrounded by the heat insulation member 63 inside the heat insulation member 63. The heat insulation member 63 is fixed to, for example, the retaining member 62, which holds the permanent magnet 61 across the heat insulation member 63. The heat insulation member 63 spacees the permanent magnet 61 from the retaining member 62. The surface 63a of the second side S2 of the heat insulation member 63 contacts the surface of the first side S1 of the mounting flange 23c of the main body 23. The outer surface of the heat insulation member 63, except for the surface 63a, is covered by the retaining member 62. That is, the heat insulation member 63 is provided in such a way that it is embedded within the retaining member 62, with only the surface 63a exposed. Thus, the heat insulation member 63 has a portion disposed between the permanent magnet 61 and the mounting flange 23c of the main body 23.

[0042] The deflector 6 uses the magnetic force of the permanent magnet 61 to deflect the electron beam B, thereby changing the position of the X-ray focus F. Viewed in the radial 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 applied appropriately to the electron beam B. In this example, viewed in the radial direction, the entire deflector 6 overlaps with the path P. The deflector 6 is mounted on the mounting flange 23c such that the virtual line connecting the opposing pair of permanent magnets 61 is approximately orthogonal to the tube axis AX. The deflector 6 can also be configured to 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.

[0043] The thermal conductivity of the retaining component 62 is higher than that of the permanent magnet 61. The thermal conductivity of the heat insulation component 63 is lower than that of the main body 23 of the housing 2 (the contact portion of the housing 2 that contacts the deflection part 6). That is, the heat insulation performance of the heat insulation component 63 is higher than that of the main body 23. Furthermore, the thermal conductivity of the heat insulation 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 insulation component 63 is, for example, about 0.1 to 0.5 W / m·K. Thermal conductivity can be measured using conventional measurement methods, such as heat flow metering, laser flash method, and hot wire method.

[0044] like Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, the heat dissipation unit 7 includes a heat sink 70 for dissipating heat generated on the target 4 and a cooling unit 80 for cooling the heat sink 70, and is disposed outside the housing 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.

[0045] The first part 71 is formed as a circular plate coaxial with the tube shaft AX, and has an opening 71b in the center. The first part 71 extends perpendicularly to the tube shaft AX along the surface 24a of the cover 24, and the protrusion 26 is disposed within the opening 71b. The first part 71 surrounds the protrusion 26 when viewed from the axial direction A. The surface of the second side S2 of the first part 71 contacts the surface 24a of the cover 24 through a sheet-like heat-conducting member 8. Thus, the first part 71 is thermally connected to the surface 24a of the cover 24. The heat-conducting member 8 is, for example, a circular sheet of silicone with high thermal conductivity, disposed between the entire surface of the surface 24a and the first part 71, and is in close contact with both the surface 24a and the first part 71. By placing the heat-conducting member 8 between the first part 71 and the cover 24, compared to the case where the first part 71 and the cover 24 are in direct contact and both are made of metal, heat conduction between the first part 71 and the cover 24 can be promoted.

[0046] like Figure 4As shown, the first portion 71 is slightly spaced from the protrusion 26 in the radial direction. The distance L1 between the first portion 71 and the protrusion 26 in the radial direction 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 smaller than the diameter (width of the protrusion 26 in the radial direction) 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 on the second side S2 relative to the surface 26a. In this example, the surface 71a is located on the same plane as the surface 26a. Furthermore, 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.

[0047] 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 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 it is also possible that only a portion of the second part 72 is located on the second side S2 of the surface 24a. The second part 72 overlaps with a portion of the main body 23 in the radial direction, covering the outer peripheral surface of a portion of the main body 23. The second part 72 is slightly spaced from the main body 23 in the radial direction, but it may also contact the main body 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.

[0048] Multiple fins 72a are formed on the outer peripheral surface of the second part 72. Each fin 72a is formed as a generally circular plate concentric with the second part 72. The multiple fins 72a are arranged parallel to each other at equal intervals along the axial direction A. Air from the cooling fan 84, described later, is supplied to the fins 72a.

[0049] The cooling section 80 includes an air supply section 81 and a generally cylindrical surrounding section 82 that surrounds the heat sink 70. The air supply section 81 includes a shroud 83 and a cooling fan 84. The shroud 83 covers one side of the cylindrical member 111 in a direction perpendicular to the axial direction A, forming a space 83a. The cooling fan 84 is disposed in the space 83a. In the shroud 83, a plurality of through holes are formed as vents 83b. The cooling fan 84 delivers external air drawn in from the vents 83b into the surrounding section 82 as cooling air.

[0050] The surrounding portion 82 has an upper wall portion 82a and a side wall portion 82b. The upper wall portion 82a is formed in an annular shape, dividing an opening 82c on the first side S1 of the surrounding portion 82. The surrounding portion 82 is configured such that the surface 71a of the first side S1 of the first portion 71 is exposed through the opening 82c. The side wall portion 82b is formed in a cylindrical shape, surrounding a plurality of fins 72a together with the upper wall portion 82a. The surrounding portion 82 constitutes a flow path through which cooling air supplied from the communication between it and the air supply portion 81 flows in the circumferential direction in the space between the plurality of fins 72a. This improves the heat dissipation efficiency of the heat sink 70. The cooling air is exhausted from a vent (not shown) provided in the side wall portion 82b. This prevents the exhausted cooling air from flowing towards the inspection object side, suppressing the influence of exhaust air during imaging. In addition, the cooling fan 84 can also operate as follows: drawing in external air from the vent provided in the side wall portion 82b and discharging it from the vent provided in the cover portion 83b. [Functions and Effects]

[0051] In the X-ray generating apparatus 100, the deflection section 6 has a heat-insulating member 63 disposed between the permanent magnet 61 and the housing 2, the thermal conductivity of the heat-insulating member 63 being lower than that of the permanent magnet 61. Therefore, even if heat generated on the target 4 is transferred to the deflection section 6, the heat-insulating member 63 can suppress this heat transfer to the permanent magnet 61, thereby preventing the permanent magnet 61 from being heated due to heat generated on the target 4. Therefore, according to the X-ray generating apparatus 100, X-rays can be stably output.

[0052] The thermal conductivity of the heat insulation component 63 is lower than that of the main body 23 of the housing 2 (the contact portion of the housing 2 that contacts the deflection part 6). Therefore, even if the heat generated on the target 4 is transferred to the deflection part 6 via the housing 2, the heat insulation component 63 can be used to suppress the heat transfer to the permanent magnet 61.

[0053] The heat insulation component 63 houses the permanent magnet 61 internally. This effectively suppresses the transfer of heat generated on the target 4 to the permanent magnet 61.

[0054] The deflection section 6 has a holding member 62 that holds the permanent magnet 61, and the thermal conductivity of the holding member 62 is higher than that of the permanent magnet 61. As a result, the heat transferred to the deflection section 6 can be dissipated to the holding member 62.

[0055] The heat insulation component 63 separates the permanent magnet 61 from the holding component 62. This prevents heat from being transferred from the holding component 62 to the permanent magnet 61.

[0056] Viewed from a direction perpendicular to the path P of the electron beam B emitted from the electron gun 3 toward the target 4, the deflection section 6 includes a portion overlapping the path P. Therefore, the electron beam B can be effectively deflected using the deflection section 6.

[0057] A heat dissipation section 7 is provided, which has a higher thermal conductivity than the permanent magnet 61 and is thermally connected to the deflection section 6. As a result, the heat transferred to the deflection section 6 can be dissipated to the heat dissipation section 7.

[0058] The heat sink 70 includes multiple fins 72a. This improves the heat dissipation performance of the heat sink 70.

[0059] The target 4 has an electron incident surface 4a and an X-ray exit surface 4b, allowing the X-rays (XR) generated by the electron beam B incident on the electron incident surface 4a to be transmitted and exited from the X-ray exit surface 4b. With this transmission-type structure, compared to a reflection-type structure where the electron incident surface also serves as the X-ray exit surface, it is easier to position the target 4 near the X-ray exit window 5, thus reducing the focal distance (FOD) (the distance from the X-ray focus F to the object being inspected). When the FOD is small, observation at high magnification is possible. Alternatively, when the magnification is the same, a bright image can be obtained because the X-ray imaging pixels can be positioned near the X-ray source.

[0060] The X-ray generating apparatus 100 (X-ray module) includes: a housing 2; an electron gun 3 that emits an electron beam B within the housing 2; a target 4 disposed within and fixed to the housing 2, which generates X-rays (XR) due to the incident electron beam B; a permanent magnet 61 disposed outside the housing 2, which deflects the electron beam B using magnetic force; and a heat dissipation section 7 having a higher thermal conductivity than the permanent magnet 61 and being thermally connected to the permanent magnet 61. Thus, the X-ray generating apparatus 100 is equipped with a heat dissipation section 7 having a higher thermal conductivity than the permanent magnet 61 and being thermally connected to the permanent magnet 61. Therefore, even if heat generated on the target 4 is transferred to the permanent magnet 61, the transferred heat can be dissipated to the heat dissipation section 7, thereby suppressing the heating of the permanent magnet 61 due to heat generated on the target 4. Therefore, according to the X-ray generating apparatus 100, X-rays (XR) can be stably output.

[0061] Viewed from a direction perpendicular to the path P of the electron beam B emitted from the electron gun 3 toward the target 4, the permanent magnet 61 includes a portion overlapping with the path P. Therefore, the permanent magnet 61 can effectively deflect the electron beam B.

[0062] The thermal conductivity of the holding member 62 holding the permanent magnet 61 is higher than that of the permanent magnet 61. Therefore, the holding member 62 can be used as part of the heat dissipation part 7 to dissipate the heat transferred to the permanent magnet 61, and the heat can also be dissipated to the heat dissipation part 7 via the holding member 62.

[0063] The heat dissipation unit 7 is thermally connected to the holding member 62. As a result, the heat transferred to the permanent magnet 61 can be effectively dissipated to the heat dissipation unit 7 via the holding member 62.

[0064] A heat insulation component 63 is provided at least between the permanent magnet 61 and the housing 2. The thermal conductivity of the heat insulation component 63 is lower than that of the permanent magnet 61. This can suppress the transfer of heat from the housing 2 to the permanent magnet 61.

[0065] The heat insulation component 63 houses the permanent magnet 61. This effectively suppresses the transfer of heat from the housing 2 to the permanent magnet 61. [Variation Example]

[0066] exist Figure 8 In the first modified example shown, the heat insulation member 63 is formed as an annular plate concentric with the retaining member 62. The heat insulation member 63 extends in a plate-like manner, separating the permanent magnet 61 from the mounting flange 23c of the main body 23, thus separating the permanent magnet 61 and the retaining member 62 from the mounting flange 23c. The heat sink 70 does not have the first part 71, but only the second part 72, and does not contact the housing 2, although it may contact the housing 2. Furthermore, the heat insulation member 63 is not limited to being a plate-like member, as long as it extends in a manner that separates the permanent magnet 61 from the mounting flange 23c of the main body 23. For example, the heat insulation member 63 may also be formed by coating a liquid and then allowing it to solidify.

[0067] According to the first variation, X-rays (XR) can be output stably in the same way as in the above embodiment. In addition, since the heat insulation member 63 extends in a plate-like manner to separate the permanent magnet 61 from the housing 2, the heat transferred to the housing 2 and then to the permanent magnet 61 can be effectively suppressed.

[0068] exist Figure 9 In the second variation shown, the heat dissipation section 7 is formed in a tubular shape. The heat dissipation section 7 is in contact with the surface of the first side S1 of the holding member 62 of the deflection section 6 and is thermally connected to the permanent magnet 61. The heat dissipation section 7 constitutes a heat pipe, sealing the working fluid inside. Alternatively, the heat dissipation section 7 can also constitute a cooling water pipe for supplying cooling water flow. The deflection section 6 can be constructed in the same way as in the first variation.

[0069] According to the second modification, X-rays (XR) can be output stably in the same manner as in the above-described embodiment. Furthermore, since the heat dissipation section 7 is formed in a tubular shape, it can be used as a heat pipe or cooling water piping, thereby improving its heat dissipation performance.

[0070] This invention is not limited to the embodiments described above. For example, the materials and shapes of each structure are not limited to those described above, and various materials and shapes can be used. The holding member 62 can be omitted. In this case, the permanent magnet 61 is held by the heat insulation member 63. The heat insulation member 63 can also be omitted. The heat dissipation part 7 can also be a cooling mechanism other than the example described above. The heat dissipation part 7 and the holding member 62 can be formed integrally, or they can be constituted by a single component. The heat dissipation part 7 can also be omitted. The protrusion 26 may not be formed on the surface 24a of the housing 2, and the surface 24a can be flat overall. Furthermore, it is also possible to configure at least a portion of the deflection part 6 and the heat dissipation part 7 to be integral with the X-ray tube 1. In the above embodiments, the X-ray module constitutes the X-ray generating device 100, but the X-ray module does not necessarily need to constitute an X-ray generating device; for example, it may only include the X-ray tube 1 and the heat dissipation part 7 (heat sink 70).

Claims

1. An X-ray module, characterized in that, include: Box; An electron gun that emits an electron beam from inside the box; A target that generates X-rays due to the incident electron beam, disposed within and fixed to the housing. and A deflection section having a permanent magnet disposed outside the housing, which uses the magnetic force of the permanent magnet to deflect the electron beam. The deflection section has at least one heat-insulating component disposed between the permanent magnet and the housing. The thermal conductivity of the heat insulation component is lower than that of the permanent magnet. The deflection section also has a holding component for retaining the permanent magnet. The thermal conductivity of the retaining component is higher than that of the permanent magnet. The permanent magnet is surrounded by the heat insulation component, which is embedded in the retaining component with only one surface of the heat insulation component exposed.

2. The X-ray module as described in claim 1, characterized in that: The thermal conductivity of the insulation component is lower than that of the contact portion of the housing with the deflector.

3. The X-ray module as described in claim 1, characterized in that: The heat insulation component houses the permanent magnet inside.

4. The X-ray module as described in claim 2, characterized in that: The heat insulation component houses the permanent magnet inside.

5. The X-ray module as described in claim 1, characterized in that: The heat insulation component extends in a manner that separates the permanent magnet from the housing.

6. The X-ray module as described in claim 2, characterized in that: The heat insulation component extends in a manner that separates the permanent magnet from the housing.

7. The X-ray module as described in claim 1, characterized in that: The heat insulation component separates the permanent magnet from the retaining component.

8. The X-ray module as described in claim 1, characterized in that: The heat insulation component is made of resin material.

9. The X-ray module as described in claim 1, characterized in that: The heat insulation component is formed of silicone resin, epoxy resin or acrylic resin that has room temperature curing properties.

10. The X-ray module as described in any one of claims 1 to 9, characterized in that: When viewed in a direction perpendicular to the path of the electron beam emitted from the electron gun toward the target, the deflection portion includes a portion that overlaps with the path.

11. The X-ray module as described in any one of claims 1 to 9, characterized in that: It also includes a heat dissipation section, which has a higher thermal conductivity than the permanent magnet and is thermally connected to the deflection section.

12. The X-ray module as described in claim 10, characterized in that: It also includes a heat dissipation section, which has a higher thermal conductivity than the permanent magnet and is thermally connected to the deflection section.

13. The X-ray module as described in claim 11, characterized in that: The heat dissipation section includes multiple fins.

14. The X-ray module as described in claim 12, characterized in that: The heat dissipation section includes multiple fins.

15. The X-ray module as described in claim 11, characterized in that: The heat dissipation section is formed in a tubular shape.

16. The X-ray module as described in claim 12, characterized in that: The heat dissipation section is formed in a tubular shape.

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