X-ray tube
By designing multiple regions with different cross-sectional areas in the filament of the X-ray tube, the problems of insufficient filament thermal management and electron emission efficiency in the existing technology are solved, and more efficient X-ray emission and more stable tube performance are achieved.
Patent Information
- Application Number
- CN202420598602.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-12
- Filing Date
- 2023-07-06
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2033-07-06
AI Technical Summary
At high voltages, the thermal management and electron emission efficiency of the existing X-ray tubes are insufficient, resulting in low emission efficiency and stability of X-rays.
A filament is designed that includes multiple areas with different cross-sectional areas. By adjusting the thickness and width of the wires, a low area, an outer high area, a central high area, and a central area are formed to ensure uniform distribution of current density, thereby increasing the temperature of the filament. management and electron emission efficiency.
By adjusting the cross-sectional area of the filament, more efficient electron emission and X-ray emission are achieved, and the emission efficiency and stability of the X-ray tube are improved.
Smart Images
Figure CN222380542U_ABST
Abstract
Description
[0001] This application is a divisional application of the application filed on July 6, 2023, with application number 202321769507.4 and entitled "X-ray tube". Technical Field
[0002] This application relates to X-ray sources. Background Technology
[0003] X-rays have many applications, including imaging, X-ray fluorescence analysis, X-ray diffraction analysis, and electrostatic dissipation. A high voltage between the cathode and anode of an X-ray tube, sometimes with a heated filament, causes electrons to be emitted from the cathode to the anode. The anode may include a target. The target generates X-rays in response to impacting electrons from the cathode. Utility Model Content
[0004] An X-ray tube may include a cathode and an anode that are electrically insulated from each other. The cathode may include a filament configured to emit electrons toward the anode. The anode may be configured to emit X-rays from the X-ray tube in response to impacting electrons from the filament.
[0005] The filament may include an elongated wire extending non-linearly in a plane between a pair of electrodes. The filament can be heated by an electric current flowing through the elongated wire due to the voltage difference between the pair of electrodes.
[0006] The filament may include a coiled section, wherein the conductor forms at least one complete turn around an axis at the center of the filament. The filament may be formed in a double-coiled shape oriented parallel to the plane.
[0007] The filament may include a pair of low regions, a pair of outer high regions, and a central high region. Each low region may be electrically coupled at one end to one of the pair of outer high regions and at the opposite end to the central high region. The low regions and the central high region may be electrically coupled between the pair of outer high regions. Due to the larger conductor cross-sectional area in the low regions, each low region may be configured to have a lower current density than the outer high region of the central high region.
[0008] This utility model relates to an X-ray tube, comprising: a cathode and an anode electrically insulated from each other, the cathode including a filament configured to emit electrons toward the anode, and the anode configured to emit X-rays from the X-ray tube in response to impacting electrons from the filament; characterized in that: the filament includes an elongated wire extending nonlinearly in a plane between a pair of electrodes, the filament being heatable by a current flowing through the elongated wire based on a voltage difference between the pair of electrodes; the filament including a low region and a pair of high regions; the low region being electrically coupled between the pair of high regions; and the low region being configured to have a lower current density during operation than the pair of high regions because its thickness is greater than that of the pair of high regions.
[0009] In some embodiments, the low region includes a pair of low regions; the filament also includes a central high region electrically coupled between the pair of low regions; each of the low regions is configured to have a lower current density than the central high region because the cross-sectional area of the conductor in the low regions is larger.
[0010] Preferably, T12 / T11 ≥ 1.1 and T12 > T13, where T11 is the thickness of the conductor in the outer high region, T12 is the thickness of the conductor in the low region, and T13 is the thickness of the conductor in the central high region. More preferably, T12 / T11 ≥ 3 and T12 / T13 ≥ 3.
[0011] Preferably, W12 > W11 and W12 > W13, where W11 is the width of the conductor in the outer high region, W12 is the width of the conductor in the low region, and W13 is the width of the conductor in the central high region. More preferably, W12 / W11 ≥ 2 and W12 / W13 ≥ 2.
[0012] In some embodiments, the width of the conductor in the low region is greater than the width of the conductor in the outer high region.
[0013] In some embodiments, W12 / W11 ≥ 1.1, where W12 is the width of the conductor in the low region and W11 is the width of the conductor in the outer high region.
[0014] In some embodiments, the low region is located at the center of the conductor, at 25% of the conductor length.
[0015] In some embodiments, the X-ray tube further includes a smooth transition of thickness between each of the outer high regions and the low regions. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1This is a top view of a filament 10 with conductors, the conductors including a pair of outer high regions 11, a pair of low regions 12, a pair of central high regions 13, and a central region 14. These regions may have different widths relative to each other (W12>W11, W12>W13, W14>W13).
[0017] Figure 2 This is a top view of a filament 20 with conductors, the conductors including a pair of outer high regions 11, a pair of low regions 12, and a central high region 13. These regions may have different thicknesses and / or different widths relative to each other.
[0018] Figure 3 This is a cross-sectional side view of a filament 30 having an outer high region 11 and a low region 12. These regions may have different thicknesses and / or widths from one another.
[0019] Figure 4 This is a cross-sectional side view of a filament 40 having an outer high region 11 and a low region 12. These regions may have different thicknesses and / or widths from one another.
[0020] Figure 5 It is a cross-sectional side view of a filament 50 having an outer pair of high regions 11, a pair of low regions 12, and a central high region 13. These regions may have different thicknesses and / or widths relative to each other.
[0021] Figure 6 This is a cross-sectional side view of a filament 60 with conductors, the conductors including a pair of outer high regions 11, a pair of low regions 12, a pair of central high regions 13, and a central region 14. These regions may have different thicknesses and / or widths from each other.
[0022] Figure 7 This is a cross-sectional side view of a filament 70 having a thin region 72 electrically coupled between a pair of thick regions 71. The thin region 72 may be thinner than the pair of thick regions 71.
[0023] Figure 8 This is a cross-sectional side view of a filament 70 having a thin region 72 electrically coupled between a pair of thick regions 71. The width W72 of the thin region 72 may be greater than the width W71 of the pair of thick regions 71. The thin region 72 may be thinner than the pair of thick regions 71.
[0024] Figure 9 This is a side view of a portion of filament 90, showing a smooth transition in thickness between adjacent areas.
[0025] Figure 10 This is a cross-sectional side view of a transmission target X-ray tube 100 having a filament 101F as described herein.
[0026] Figure 11 This is a cross-sectional side view of a transmission target X-ray tube 110 having a filament 101F as described herein.
[0027] Figure 12 This is a cross-sectional side view of an X-ray tube 120 with a side-window reflective target having a filament 101F as described herein.
[0028] Figure 13 This is a cross-sectional side view illustrating one step in a method of manufacturing a spiral filament, the method comprising providing a metal plate 131 having a plurality of different thicknesses Th.
[0029] Figure 14 This is a top view illustrating one step in a method for manufacturing a coiled filament with multiple thicknesses, the method comprising applying a mask 142 to a desired thicker area of a metal plate 141 and then etching the exterior of the mask 142 to form multiple different thicknesses.
[0030] Figure 15 This is a top view illustrating one step in a method for manufacturing a coiled filament, the method comprising applying a mask 142 at a planned location for an elongated shape 151 of the coiled filament on a metal plate 141 having a plurality of different thicknesses, and then etching the exterior of the mask 142 to form the elongated shape 151.
[0031] Figure 16 This is a side view illustrating one step in a method of manufacturing a spiral filament, the method comprising cutting an elongated shape 151 of the spiral filament using a laser 161.
[0032] Figure 17 This is a top view illustrating one step in a method for manufacturing a spiral filament, the method comprising applying a mask 142 over a planned thicker area of an elongated shape 151 and then etching the exterior of the mask 142 to form a plurality of elongated shapes 151 of varying thicknesses.
[0033] In the picture:
[0034] Filament 10, 20, 30, 40, 50, 60, 70, 80, 90
[0035] Waigao District 11
[0036] Low Zone 12
[0037] Central High Zone 13
[0038] Central Area 14
[0039] Electrode 15
[0040] Shaft 16
[0041] Plane 31
[0042] thick area 71
[0043] Thin area 72
[0044] X-ray tubes with transmission targets 100, 110
[0045] Cathode 101
[0046] Filament 101F
[0047] Anode 102
[0048] X-ray window 103
[0049] Target 104
[0050] Electrically insulating casing 105
[0051] 120 side-window reflective target X-ray tube
[0052] Metal plates 131 with multiple thicknesses Th
[0053] A planar metal plate 132 with one side of a metal plate 131 having multiple metal plates of different thicknesses Th 141
[0054] Mask 142
[0055] 151 slender shape
[0056] Laser 161
[0057] Transition height H
[0058] Transition length L
[0059] The conductor thickness T11 in the outer high region 11
[0060] The conductor thickness T12 in the lower region 12
[0061] The conductor thickness T13 in the central high region 13
[0062] The conductor thickness T14 in the central region 14
[0063] The conductor thickness T71 in thick region 71
[0064] The conductor thickness T72 in thin region 72
[0065] The conductor width W11 in the outer high region 11
[0066] The conductor width W12 in the lower region 12
[0067] The conductor width W13 in the central high area 13
[0068] The conductor width W14 in the central region 14
[0069] The conductor width W71 in thick region 71
[0070] The conductor width W72 in thin region 72
[0071] As used herein, “in,” “located,” and “above” mean directly above or between which there is some other solid material. The terms “directly located” and “adjacent” mean direct and immediate contact.
[0072] As used herein, the term "identical cross-sectional area" means that the conductors have exactly the same cross-sectional area; the conductors have the same cross-sectional area within normal manufacturing tolerances; or the conductors have nearly identical cross-sectional areas such that any deviation from having the same cross-sectional area as the conductors has negligible impact on the normal use of the equipment.
[0073] As used herein, the term "identical thickness" means exactly the same thickness; the same thickness within normal manufacturing tolerances; or almost identical thickness, such that any deviation from exactly the same thickness has negligible impact on the normal use of the equipment.
[0074] As used herein, the term "identical width" means exactly the same width; the same width within normal manufacturing tolerances; or nearly identical width, such that any deviation from exactly the same width will have a negligible effect on the normal use of the equipment.
[0075] As used herein, the term "X-ray tube" is not limited to tubular / cylindrical devices. The term "tube" is used because it is the standard term for X-ray emitting equipment.
[0076] When comparing thicknesses, if the region has multiple thicknesses, the largest thickness in the region is used for comparison. Similarly, when comparing widths, if the region has multiple widths, the largest width in the region is used for comparison. Detailed Implementation
[0077] Having different filament cross-sectional areas at different locations has many advantages, including (a) concentrating and increasing electron emission from the filament center, (b) increasing the rate of filament temperature rise, and (c) stabilizing vulnerable locations of the filament.
[0078] In regions with smaller cross-sectional areas, higher current densities may exist, thus increasing the heat generated in the conductor. In regions with larger cross-sectional areas, lower current densities may exist, thus reducing the heat generated in the conductor. This increase and decrease in heat affects the overall conductor temperature. By adjusting the cross-sectional area of the conductor at different locations, electron emission can be largely confined to preferred regions, such as the center of the filament. For example, ≥50% or ≥90% of electrons can be emitted from the center 25% of the filament.
[0079] The central region 14 of the filament can be wider to increase the area for electron emission. The central region 14 can also be thinner to increase the current density and heat at the center. Therefore, the wider and thinner central region 14 of the filament can work together to increase electron emission from that central region 14. The wider and thinner central region 14 can also increase the rate of temperature rise in the filament, thereby allowing for the emission of faster electron pulses. The central region 14 of the filament can be wider, thinner, or both than any other part of the filament.
[0080] Typically, the filament has a higher temperature in its central region 14. Due to the higher temperature, the grain structure of the central region can differ from that of the outer ends. The filament can prematurely split at the transition between these different grain structure locations. It is beneficial to strengthen this location by increasing the cross-sectional area of the filament at that location. The filament region with an increased cross-sectional area can have more grains and more grain boundaries, and therefore can be more robust.
[0081] The filaments in this article can be planar or coiled. These filaments can be included in planar 31 (see...). Figure 3-9 A slender wire extending non-linearly within a [structure / mechanism]. It should be noted that... Figure 1 and Figure 2 The planes of filaments 10 and 20 are parallel to the plate. For example... Figure 10-12 As shown, plane 31 may be perpendicular to axis 16 extending between cathode 101 and target 104 of X-ray tubes 100, 110 and 120.
[0082] One advantage of the spiral shape is that it avoids jagged corners. Another advantage is that the electrons emitted from the central circular region cause X-ray emission in the target 104 to produce a central circular region ( Figure 10-12 This allows X-rays to be focused to a smaller focal point.
[0083] The filament may include a coiled section, and the conductor forms at least one complete loop around the axis 16 on both sides of the central region 14. Thus, the filament can be formed in a double-coiled shape parallel to the plane 31.
[0084] like Figure 1 and 6As shown, the filament 10 and / or 60 may include a pair of outer high regions 11, a pair of low regions 12, a pair of central high regions 13, and a central region 14. Each low region 12 may be electrically coupled to one of the outer high regions 11 at one end and electrically coupled to one of the central high regions 13 at the opposite end. The central region 14 may be electrically coupled between the pair of central high regions 13. Thus, these regions may be arranged along the filament and / or conductor in the following order: outer high region 11, low region 12, central high region 13, central region 14, central high region 13, low region 12, and then outer high region 11.
[0085] like Figure 2 and 5 As shown, filament 20 and / or 50 may include a pair of outer high regions 11, a pair of low regions 12, and a central high region 13. Each low region 12 may be electrically coupled to one of the outer high regions 11 at one end and to one of the central high regions 13 at the opposite end. Thus, these regions may be arranged along the filament and / or wire in the following order: outer high region 11, low region 12, central high region 13, low region 12, and then outer high region 11.
[0086] like Figure 3 and Figure 4 As shown, the filament may include an outer high region 11 and a low region 12. The low region 12 may be electrically coupled between the outer high regions 11. Therefore, these regions may be arranged in the following order: outer high region 11, low region 12, and then outer high region 11.
[0087] For the filament in this paper, different regions may have different cross-sectional areas (A12, A11, A13) relative to each other, and therefore different current densities relative to each other, for shaping the electron beam and / or for reinforcing selected regions of the filament. The cross-sectional area (A12, A11, A13) of the square or rectangular conductor may be the width of the conductor multiplied by the thickness of the conductor.
[0088] For example, the conductor cross-sectional area A12 of the lower region 12 can be greater than the conductor cross-sectional area A11 of the adjacent upper region 11. The following are examples of the comparison between the conductor cross-sectional area A12 of the lower region 12 and the conductor cross-sectional area A11 of the upper region 11: A12>A11, A12 / A11≥1.05, A12 / A11≥1.1, A12 / A11≥1.2, A12 / A11≥1.5, A12 / A11≥2, A12 / A11≥3 or A12 / A11≥4.
[0089] Due to these differences in the cross-sectional areas of the conductors A12 and A11, the low region 12 can have a lower current density than the adjacent high region 11. For example, each low region 12 can have a current density that is at least 10%, at least 15%, at least 25%, or at least 50% lower than the adjacent high region 11 during operation.
[0090] The conductor cross-sectional area A12 of the low region 12 can be greater than the conductor cross-sectional area A13 of the adjacent central high region 13. The following are examples of the comparison between the conductor cross-sectional area A12 of the low region 12 and the conductor cross-sectional area A13 of the central high region 13: A12>A13, A12 / A13≥1.05, A12 / A13≥1.1, A12 / A13≥1.2, A12 / A13≥1.5, A12 / A13≥2, A12 / A13≥3 or A12 / A13≥4.
[0091] Due to these differences in the cross-sectional areas of the conductors A12 and A13, the low region 12 can have a lower current density than the adjacent central high region 13. For example, each low region 12 can have a current density that is at least 10%, at least 15%, at least 25%, or at least 50% lower than the adjacent central high region 13 during operation.
[0092] The conductor cross-sectional area A14 of the central region 14 can be greater than the conductor cross-sectional area A13 of the adjacent central high region 13. The following are examples of the comparison between the conductor cross-sectional area A14 of the central region 14 and the conductor cross-sectional area A13 of the adjacent central high region 13: A14>A13, A14 / A13≥1.05, A14 / A13≥1.1, A14 / A13≥1.2, A14 / A13≥1.5, A14 / A13≥2, A14 / A13≥3, or A14 / A13≥4.
[0093] Due to these differences in the cross-sectional areas of the conductors A14 and A13, the central region 14 can have a lower current density than the adjacent central high region 13. For example, the central region 14 can have a current density during operation that is at least 10%, at least 15%, at least 25%, or at least 50% lower than that of the adjacent central high region 13.
[0094] The current density of each central high region 13 during operation can be 1.05 times, 1.1 times, 1.2 times, 1.5 times, 2 times, or 4 times the current density of the low region 12 and / or the central region 14 adjacent to the central high region 13.
[0095] The above relationship between different area values in different regions may be due to different widths, different thicknesses, or both. Figure 1 , 2 4 and 4 indicate different widths. Figure 3-6Different thicknesses are shown. Figure 4 This demonstrates different widths and different thicknesses. Combinations of different widths and thicknesses are shown on filament 40, which can be included in any of the embodiments described herein.
[0096] The following are examples of the relationships between the conductor width W12 of the low region 12 and the conductor width W11 of the outer high region 11: W12>W11, W12 / W11≥1.05, W12 / W11≥1.1, W12 / W11≥1.2, W12 / W11≥1.5, W12 / W11≥2, W12 / W11≥3, or W12 / W11≥4. The following are examples of the relationships between the conductor width W12 of the low region 12 and the conductor width W13 of the central high region 13: W12>W13, W12 / W13≥1.05, W12 / W13≥1.1, W12 / W13≥1.2, W12 / W13≥1.5, W12 / W13≥2, W12 / W13≥3, or W12 / W13≥4. Here are some examples of the relationships between the conductor width W14 of the central region 14 and the conductor width W13 of the central high region 13: W14 > W13, W14 / W13 ≥ 1.05, W14 / W13 ≥ 1.1, W14 / W13 ≥ 1.2, W14 / W13 ≥ 1.5, W14 / W13 ≥ 2, W14 / W13 ≥ 3, or W14 / W13 ≥ 4.
[0097] The following are examples of the relationships between the conductor thickness T12 of the low region 12 and the conductor thickness T11 of the outer high region 11: T12>T11, T12 / T11≥1.05, T12 / T11≥1.1, T12 / T11≥1.2, T12 / T11≥1.5, T12 / T11≥2, T12 / T11≥3, or T12 / T11≥4. The following are examples of the relationships between the conductor thickness T12 of the low region 12 and the conductor thickness T13 of the central high region 13: T12>T13, T12 / T13≥1.05, T12 / T13≥1.1, T12 / T13≥1.2, T12 / T13≥1.5, T12 / T13≥2, T12 / T13≥3, or T12 / T13≥4. The following are examples of the relationships between the conductor thickness T14 in the central region 14 and the conductor thickness T13 in the central high region 13: T14>T13, T14 / T13≥1.05, T14 / T13≥1.1, T14 / T13≥1.2, T14 / T13≥1.5, T14 / T13≥2, T14 / T13≥3, or T14 / T13≥4.
[0098] like Figure 7 and 8As shown, filament 70 and / or 80 may include a thin region 72 and a pair of thick regions 71. The thin region 72 may be electrically coupled between the pair of thick regions 71.
[0099] The thin region 72 can be thinner than a pair of thick regions 71. This increases the current density in the thin region 72 located at the center of the conductor. This increase in current density can increase the conductor temperature in the desired electron emission region. For example, T71 / T72 ≥ 1.05, T71 / T72 ≥ 1.1, T71 / T72 ≥ 1.2, T71 / T72 ≥ 1.5, T71 / T72 ≥ 2, T71 / T72 ≥ 3, or T71 / T72 ≥ 4. T71 is the conductor thickness in the pair of thick regions 71. T72 is the conductor thickness in the thin region 72.
[0100] The thin region 72 can be wider than a pair of thick regions 71. This increases the area for electron emission. For example, W72 / W71 ≥ 1.05, W72 / W71 ≥ 1.1, W72 / W71 ≥ 1.2, W72 / W71 ≥ 1.5, W72 / W71 ≥ 2, W72 / W71 ≥ 3, or W72 / W71 ≥ 4. W72 is the conductor width of the thin region 72. W71 is the conductor width of the pair of thick regions 71.
[0101] The boundary between each thick region 71 and thin region 72 can be located at the center of 25% of the conductor length. The thin region 72 can be located entirely at the center of 25% of the conductor length.
[0102] Therefore, making the wire thinner (to increase current density) and wider (to increase electron emission area) can significantly increase electron emission at the center of the filament. This results in the formation of a small electron focusing point on the target.
[0103] In any filament described herein, the cross-sectional area of the conductor can transition smoothly between regions to avoid abrupt electric field gradients.
[0104] like Figure 1 and Figure 2 As shown, the widths between the outer high region 11 and the low region 12, between the low region 12 and the central high region 13, and between the central high region 13 and the central region 14 can be smoothly transitioned. This smooth transition of width can be applied to any filament in this document that has a width difference between adjacent regions. If the filament pattern is formed by etching, the mask can be adjusted to create this smooth transition.
[0105] like Figure 9As shown, there can be a smooth transition in thickness between adjacent regions (a smooth transition between thickness T92 and thickness T91). If the filament is formed by laser cutting, the laser settings can be adjusted to create such a smooth transition between different thicknesses. These laser settings include one or more of laser time, power level, and beam size. This smooth transition in thickness can be applied to any filament in this document that has a thickness difference between adjacent regions. The laser settings can be adjusted for the desired thickness and the smooth transition of thickness between regions.
[0106] This smooth transition in width, thickness, or both can be any non-abrupt transition. The transition can be linear, chamfered, curved, etc. The transition length L can be at least 30% of the transition height H (L ≥ 0.3 * H), see [link to relevant documentation]. Figure 1 and 9 .
[0107] The boundary between each low region 12 and its adjacent central high region 13 may be located at the center of 25% of the conductor length. A pair of low regions 12 may be located at the center of 25% of the conductor length.
[0108] The conductor can have the same cross-sectional area throughout the entire outer high region 11. The conductor can also have the same cross-sectional area throughout the entire central high region 13. Therefore, substantially uniform heat can exist in each of these regions.
[0109] Figure 10-12 X-ray tubes 100, 110, and 120 are shown, each having a filament 101F as described herein. Each X-ray tube may include a filament 101F having an elongated wire extending non-linearly in a plane 31 between a pair of electrodes 15. The filament 101F can be heated by an electric current flowing through the elongated wire due to the voltage difference between the pair of electrodes 15.
[0110] Each X-ray tube may include a cathode 101 and an anode 102 that are electrically insulated from each other. An electrically insulating housing 105 may insulate the cathode 101 from the anode 102. The cathode 101 may include a filament 101F. The filament 101F may be configured to emit electrons toward the anode 102. The anode 102 may include a target 104 configured to generate X-rays. In response to impacting electrons from the filament 101F, X-rays may be emitted through the X-ray window 103 and exit the X-ray tube.
[0111] The following are methods for manufacturing coiled filaments of various thicknesses. The steps of these methods can be performed in the order shown. The coiled filaments can possess the properties described above.
[0112] A method for manufacturing coiled filaments of various thicknesses may include the following steps, which may be performed in the following order:
[0113] (a) Providing metal plates 131 with multiple thicknesses Th ( Figure 13 Multiple thicknesses Th are measured from a plane 132 perpendicular to the surface of the metal plate 131; and
[0114] (b) Using laser 161 ( Figure 16 ), etching Figure 15 (or both) cut an elongated shape 151 of a coiled filament in a metal plate 131, such that different portions of the elongated shape 151 have multiple different thicknesses Th.
[0115] In the above method, providing multiple different thicknesses Th for the metal sheet 131 may include applying a mask 142 to the planned thicker area of the metal sheet 131, and then etching the exterior of the mask 142 to form multiple different thicknesses Th (see...). Figure 14 Then, mask 142 can be chemically removed. This step can be repeated for more than two different thicknesses Th, where mask 142 is located at different locations.
[0116] In the above method, cutting the elongated shape 151 of the coiled filament may include applying a mask 142 to the planned location of the elongated shape 151 on a metal plate 131, and then etching the exterior of the mask 142 to form the elongated shape 151. See also Figure 15 Then, mask 142 can be chemically removed before using the spiral filament.
[0117] In the above method, cutting elongated shapes may include using a laser 161. This may further include using a laser setup that tapers gradually between different thicknesses to create a smooth thickness transition between the different thicknesses. See Figure 16 .
[0118] Another method for manufacturing coiled filaments with various thicknesses may include the following steps, which may be performed in the following order:
[0119] (a) Using laser 161 ( Figure 16 ), etching Figure 15 ) or both are cut into elongated shapes of coiled filaments in a metal plate 151; and
[0120] (b) Apply mask 142 to the thicker area of the elongated shape 151. Figure 17 Then, the exterior of the mask 142 is etched to form multiple elongated shapes 151 of different thicknesses.
[0121] Then, mask 142 can be chemically removed after step (b). For more than two different thicknesses Th, step (b) can be repeated, where mask 142 is located at different positions.
[0122] Another method for manufacturing a coiled filament with multiple different thicknesses may include cutting elongated shapes 151 of the coiled filament in a metal sheet using a laser 161, and using different amounts of laser cutting in different areas to form multiple different thicknesses. The method may also include using a laser setup that gradually tapers between different areas to create a smooth thickness transition between the different areas.
Claims
1. An X-ray tube, comprising: a cathode and an anode electrically insulated from each other, the cathode including a filament configured to emit electrons toward the anode, and the anode configured to emit X-rays from the X-ray tube in response to impinging electrons from the filament; It is characterized by: The filament includes an elongated wire extending in a plane non-linearly between a pair of electrodes, the filament being capable of being heated by a current flowing through the elongated wire based on a voltage difference between the pair of electrodes; The filament includes a low region and a pair of outer high regions; The lower region is electrically coupled between the pair of outer higher regions; and Since the thickness in the low region is greater than the thickness in the pair of outer high regions, the low region is configured to have a lower current density than the pair of outer high regions during operation.
2. The X-ray tube according to claim 1, characterized in that : The low area includes a pair of low areas; The filament also includes a central high region electrically coupled between the pair of low regions; Each of the low regions is configured to have a lower current density than the central high region due to the larger cross-sectional area of the wire in the low regions.
3. The X-ray tube according to claim 2, characterized in that: T12 / T11≥1.1 and T12>T13, wherein T11 is the thickness of the conductive line in the outer high region, T12 is the thickness of the conductive line in the low region, and T13 is the thickness of the conductive line in the central high region.
4. The X-ray tube according to claim 3, characterized in that: T12 / T11≥3 and T12 / T13≥3.
5. The X-ray tube according to claim 2, characterized in that: W12>W11 and W12>W13, where W11 is the width of the conductive line in the outer high region, W12 is the width of the conductive line in the low region, and W13 is the width of the conductive line in the central high region.
6. The X-ray tube according to claim 5, characterized in that: W12 / W11≥2 and W12 / W13≥2.
7. The X-ray tube according to claim 1, characterized in that: The width of the conductive line in the low region is greater than the width of the conductive line in the outer high region.
8. The X-ray tube according to claim 1, characterized in that: W12 / W11≥1.1, wherein W12 is the width of the conductive line in the low region, and W11 is the width of the conductive line in the outer high region.
9. The X-ray tube according to claim 1, characterized in that: The low area is located at the center of the wire and 25% of the length of the wire.
10. The X-ray tube according to claim 1, characterized in that: The X-ray tube further comprises a smooth transition in thickness between each of the outer high regions and the low regions.