X-ray source voltage shield
11195687 · 2021-12-07
Assignee
Inventors
Cpc classification
H05G1/06
ELECTRICITY
International classification
Abstract
A shield around an x-ray tube, a voltage multiplier, or both can improve the manufacturing process by allowing testing earlier in the process and by providing a holder for liquid potting material. The shield can also improve voltage standoff. A shielded x-ray tube can be electrically coupled to a shielded power supply.
Claims
1. A method of manufacture of an x-ray source, the method comprising: inserting an x-ray tube inside of an x-ray tube shield, the x-ray tube shield wrapping at least a portion of the x-ray tube with a gap between the x-ray tube shield and the x-ray tube, the x-ray tube shield being electrically insulative; inserting an x-ray tube potting compound into the gap between the x-ray tube shield and the x-ray tube, the x-ray tube potting compound being a liquid and being adjacent to both the x-ray tube shield and the x-ray tube; curing the x-ray tube potting compound into a solid, electrically insulative material, defining x-ray tube insulation, the x-ray tube insulation having a material composition different from a material composition of the x-ray tube shield; inserting a voltage multiplier inside of a power supply shield, the power supply shield wrapping at least a portion of the voltage multiplier with a gap between the power supply shield and the voltage multiplier, the power supply shield being electrically insulative, the power supply shield being separate and spaced apart from the x-ray tube shield; inserting a power supply potting compound into the gap between the power supply shield and the voltage multiplier, the power supply potting compound being a liquid and being adjacent to both the power supply shield and the voltage multiplier; and curing the power supply potting compound into a power supply insulation, the power supply insulation being a solid, electrically insulative material with a material composition different from a material composition of the power supply shield.
2. The method of claim 1, wherein the material composition of the x-ray tube insulation and the material composition of the power supply insulation each include a polymer.
3. The method of claim 1, wherein: the x-ray tube insulation and the power supply insulation each have a Shore hardness of ≥20A and ≤90A and electrical resistivity of at least 10.sup.14 ohm*cm; and the x-ray tube shield and the power supply shield each have a Vickers hardness of ≥5 GPa and ≤22 GPa.
4. The method of claim 1, wherein: a hardness of the x-ray tube shield is greater than a hardness of the x-ray tube insulation; and a hardness of the power supply shield is greater than a hardness of the power supply insulation.
5. The method of claim 1, wherein: the gap between the x-ray tube shield and the x-ray tube is an annular gap; inserting the x-ray tube potting compound includes filling the gap between the x-ray tube shield and the x-ray tube with the x-ray tube potting compound; the gap between the power supply shield and the voltage multiplier is an annular gap; and inserting the power supply potting compound includes filling the gap between the power supply shield and the voltage multiplier with the power supply potting compound.
6. The method of claim 1, further comprising the following steps performed in the order of step (a), step (b), and then step (c): (a) testing performance of the x-ray tube after curing the x-ray tube potting compound and testing performance of the voltage multiplier after curing the power supply potting compound, making an electrical connection between a voltage multiplier and the x-ray tube, and placing the voltage multiplier and the x-ray tube at least partially inside of an enclosure; (b) inserting an outer potting compound into the enclosure, the outer potting compound being a liquid and at least partially surrounding the electrical connection, the voltage multiplier, and the x-ray tube; and then (c) curing the outer potting compound into an outer insulation, the outer insulation being solid and electrically insulative, and having a material composition different from a material composition of the power supply shield and of the x-ray tube shield.
7. The method of claim 6, wherein: the x-ray tube shield and the power supply shield are electrically insulative; the material composition of the x-ray tube shield and the material composition of the power supply shield are inorganic; and the material composition of the x-ray tube insulation, the material composition of the power supply insulation, and the material composition of the outer insulation are organic.
8. The method of claim 6, wherein the enclosure is electrically conductive.
9. A method of manufacture of a shielded x-ray tube, the method comprising: inserting an x-ray tube inside of an x-ray tube shield, the x-ray tube shield wrapping at least a portion of the x-ray tube with a gap between the x-ray tube shield and the x-ray tube, and the x-ray tube shield being electrically insulative; inserting an x-ray tube potting compound into the gap between the x-ray tube shield and the x-ray tube, the x-ray tube potting compound being a liquid and being adjacent to both the x-ray tube shield and the x-ray tube; and curing the x-ray tube potting compound into a solid, electrically insulative material, defining x-ray tube insulation, the x-ray tube insulation having a material composition different from a material composition of the x-ray tube shield.
10. The method of claim 9, wherein the x-ray tube shield is electrically insulative, the material composition of the x-ray tube shield is inorganic, and the material composition of the x-ray tube insulation is organic.
11. The method of claim 9, further comprising the following steps performed in the order of step (a), step (b), and then step (c): (a) testing performance of the x-ray tube after curing the x-ray tube potting compound, making an electrical connection between a voltage multiplier and the x-ray tube, and placing the voltage multiplier and the x-ray tube at least partially inside of an enclosure; (b) inserting an outer potting compound into the enclosure, the outer potting compound being a liquid and at least partially surrounding the electrical connection, the voltage multiplier, and the x-ray tube; and (c) curing the outer potting compound into an outer insulation, the outer insulation being solid, electrically insulative, and having a material composition different from a material composition of the x-ray tube shield.
12. The method of claim 11, wherein: a relative permittivity of the x-ray tube shield is greater than a relative permittivity of the outer insulation; and the relative permittivity of the outer insulation is greater than a relative permittivity of the x-ray tube insulation.
13. The method of claim 11, wherein the enclosure is electrically conductive.
14. A method of manufacturing a shielded power supply, the method comprising: inserting a voltage multiplier inside of a power supply shield, the power supply shield wrapping at least a portion of the voltage multiplier with a gap between the power supply shield and the voltage multiplier, and the power supply shield being electrically insulative; inserting a power supply potting compound into the gap between the power supply shield and the voltage multiplier, the power supply potting compound being a liquid and being adjacent to both the power supply shield and the voltage multiplier; and curing the power supply potting compound into a power supply insulation, the power supply insulation being a solid, electrically insulative material with a material composition different from a material composition of the power supply shield.
15. The method of claim 14, wherein a hardness of the power supply shield is greater than a hardness of the power supply insulation.
16. The method of claim 14, wherein: the material composition of the power supply insulation includes a polymer; the power supply insulation has a Shore hardness of ≥20A and ≤90A and electrical resistivity of at least 10.sup.14 ohm*cm; and the power supply shield has a Vickers hardness of ≥5 GPa and ≤22 GPa.
17. The method of claim 14, further comprising the following steps performed in the order of step (a), step (b), and then step (c): (a) testing performance of the voltage multiplier after curing the power supply potting compound, making an electrical connection between the voltage multiplier and an x-ray tube, and placing the voltage multiplier and the x-ray tube at least partially inside of an enclosure; (b) inserting an outer potting compound into the enclosure, the outer potting compound being a liquid and at least partially surrounding the electrical connection, the voltage multiplier, and the x-ray tube; and then (c) curing the outer potting compound into an outer insulation, the outer insulation being solid, electrically insulative, and having a material composition different from a material composition of the power supply shield.
18. The method of claim 17, wherein the enclosure is electrically conductive.
19. The method of claim 17, wherein the power supply shield is electrically insulative, the material composition of the power supply shield is inorganic, the material composition of the power supply insulation is organic, and the material composition of the outer insulation is organic.
20. The method of claim 17, wherein: a relative permittivity of the power supply shield is greater than the relative permittivity of the outer insulation; and the relative permittivity of the outer insulation is greater than a relative permittivity of the power supply insulation.
Description
BRIEF DESCRIPTION OF THE DRAWINGS (DRAWINGS MIGHT NOT BE DRAWN TO SCALE)
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DEFINITIONS
(20) As used herein, the term “adjoin” means direct and immediate contact.
(21) As used herein, the term “GPa” means gigaPascal.
(22) As used herein, the term “kV” means kilovolt(s).
(23) As used herein, the term “mm” means millimeter(s).
(24) As used herein, the term “parallel” means exactly parallel, or within 30° of exactly parallel. The term “parallel” can mean within 0.1°, within 1°, within 5°, within 10°, within 15°, or within 20° of exactly parallel if explicitly so stated in the claims.
(25) As used herein, the term “x-ray tube” means a device for producing x-rays, and which is traditionally referred to as a “tube”, but need not be tubular in shape.
DETAILED DESCRIPTION
(26) As illustrated in
(27) The shield 11 can be electrically insulative to improve high voltage standoff, reduce amount and weight of electrical insulation, or both. For example, an electrical resistivity of the shield 11 can be ≥10.sup.6 ohm*m, ≥10.sup.8 ohm*m, ≥10.sup.10 ohm*m, or ≥10.sup.12 ohm*m. Sometimes, an electrically conductive shield is desirable to help mitigate unwanted electromagnetic interference. For example, an electrical resistivity of the shield 11 can be ≤10.sup.−4 ohm*m, ≤0.01 ohm*m, ≤0.1 ohm*m, or ≤1 ohm*m. It can be helpful, for blocking electromagnetic interference, for the shield to have some electrical resistance. Therefore, the shield 11 can have electrical resistivity of ≥10.sup.−8 ohm*m, ≥10.sup.−7 ohm*m, ≥10.sup.−6 ohm*m, or ≥10.sup.−5 ohm*m. All resistivity values herein are at 20° C.
(28) The shield can include high atomic number (Z) materials for blocking stray x-rays. For example, the shield can include material(s) with Z≥24, Z≥40, or Z≥73.
(29) Some high voltage components, including x-ray sources, may need high temperature processing during manufacture. Thus, high temperature resistance can be important. For example, the shield 11 can have a melting point of ≥250° C., ≥400° C., ≥500° C., or ≥600° C.
(30) Example materials of the shield 11, which can meet the above criteria, include ceramic, plastic, glass, polymer, polyimide or combinations thereof. These materials can be impregnated with other materials such as metals or metalloids to provide the desired properties as described above.
(31) As illustrated in
(32) As illustrated in
(33) As shown in
(34) Another possible shape of the shield 11, illustrated in
(35) As illustrated in
(36) The shield 11 can have sufficient thickness Th.sub.s (
(37) The shield 11 can be thin to avoid unnecessary added weight. For example, the thickness Th.sub.s of the shield can include: ≤5 mm, ≤10 mm, or ≤25 mm. This thickness Th.sub.s can be a maximum thickness of the entire shield 11 if explicitly so stated in the claims.
(38) As illustrated in
(39) As illustrated on high voltage component 100 in
(40) As illustrated on high voltage component 120 in
(41) Alternatively, as illustrated on high voltage component 130 in
(42) As illustrated on in
(43) As illustrated in
(44) As illustrated in
(45) An enclosure 181 can at least partially surround the electrical connection 182, the x-ray tube 163 (or shielded x-ray tube 160), and the voltage multiplier 143 (or shielded power supply 140). An outer insulation 202 can electrically insulate the enclosure 181 from these components located therein. The outer insulation 202 can be solid and electrically insulative material. The outer insulation 202 can be sandwiched between the enclosure 181 and the electrical connection 182, the shielded x-ray tube 160, and the power supply 140. The enclosure 181 can be electrically conductive.
(46) Following are characteristics of materials of the components of the various embodiments of the inventions described herein. A material composition of the shield 11, the high voltage insulation 22, and the outer insulation 202 can be selected for optimal insulation of the high voltage device(s) 13 from the enclosure 181 or other grounded components. For example, a material composition of the shield 11 can be different than a material composition of the high voltage insulation 22, different than a material composition of the outer insulation 202, or both.
(47) Further, for optimal insulation of the high voltage device(s) 13, a relative permittivity of the shield 11 can be greater than a relative permittivity of the outer insulation 202, greater than relative permittivity of the high voltage insulation 22, or both. For example, relative permittivity of the shield 11 divided by relative permittivity of the high voltage insulation 22 can be ≥1.5, ≥2, ≥2.5, ≥3, or ≥5 The relative permittivity of the outer insulation 202 can be greater than a relative permittivity of the high voltage insulation 22. For example, relative permittivity of the outer insulation 202 divided by relative permittivity of the high voltage insulation 22 can be ≥1.3, ≥1.5, ≥2, ≥2.5, or ≥3.
(48) Also, for optimal insulation of the high voltage device(s) 13, material composition of the shield 11 can be inorganic, material composition of the high voltage insulation 22 can be organic, material composition of the outer insulation 202 can be organic, or combinations thereof. Material composition of the high voltage insulation 22, material composition of the outer insulation 202, or both, can include a polymer. The shield 11 can be harder than the high voltage insulation 22, harder than the outer insulation 202, or both. For example, the high voltage insulation 22, the outer insulation 202, or both, can have a Shore hardness of ≥10A, ≥20A, ≥30A, ≥40A, or ≥45A and ≤65A, ≤70A, ≤80A, or ≤90A. For example, the shield 11 can have a Vickers hardness of ≥2.5 GPa, ≥5 GPa, ≥10 GPa, or ≥13 GPa and ≤17.5 GPa, ≤20 GPa, or ≤22 GPa.
(49) A method of manufacturing a high voltage component can comprise some or all of the following steps, which can be performed in the following order. There may be additional steps not described below. These additional steps may be before, between, or after those described.
(50) As illustrated in
(51) As illustrated in
(52) The shield 11 can have various shapes for holding the liquid, such as for example a cube or a cylinder. Alternatively, the shield 11 can have a partially open shape such as shown in
(53) As illustrated in
(54) Another step can include testing performance of the high voltage device 13. For example, if the high voltage device 13 is a voltage multiplier 143, its voltage output capabilities can be tested now that it is embedded in the power supply insulation 142. As another example, if the high voltage device 13 is an x-ray tube 163, a bias voltage of several kilovolts can be applied between the cathode 165 and the anode 164, its electron emitter can be activated, and its x-ray output can be analyzed. It can be advantageous to test at this stage, before connecting the voltage multiplier 143 to the x-ray tube 163, and adding outer insulation 202 around both devices, because after this latter step, both devices may need to be scrapped if one is defective. Thus, it is helpful to know earlier in the process whether one of the high voltage devices 13 is functional.
(55) Some or all of the above steps can be performed on a voltage multiplier 143, on an x-ray tube 163, or each of these two devices separately. As illustrated in
(56) As illustrated in
(57) As illustrated in
(58) The above method can allow a relatively easier method for manufacture of x-ray sources with reduced scrap parts. The above method can also provide relatively small, light x-ray sources with high voltage standoff capabilities relative to size.