X-ray source voltage shield

Patent metadata

Field	Value
Publication number	US-10964507-B2
Application number	US-201916387455-A
Country	US
Kind code	B2
Filing date	Apr 17, 2019
Priority date	May 10, 2018
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

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.

First claim

What is claimed is:

1. A shielded x-ray source comprising:
a shielded x-ray tube including:
an x-ray tube configured to emit x-rays;
an x-ray tube shield wrapping at least partially around the x-ray tube;
the x-ray tube shield spaced apart from the x-ray tube by an arcuate gap; and
x-ray tube insulation separating the x-ray tube shield from the x-ray tube, the x-ray tube insulation comprising a solid, electrically-insulative material with a different material composition than a material composition of the x-ray tube shield;

a shielded power supply including:
a voltage multiplier;
a power supply shield wrapping at least partially around the voltage multiplier, the power supply shield being spaced apart from the voltage multiplier by a gap;
power supply insulation separating the power supply shield from the voltage multiplier; and
the power supply insulation comprising a solid, electrically-insulative material having a different material composition than a material composition of the power supply shield;

the x-ray tube electrically coupled to the voltage multiplier; and
the x-ray tube shield separate from and spaced apart from the power supply shield.

2. The shielded x-ray source of claim 1 , further comprising:
an enclosure at least partially surrounding the shielded power supply and the shielded x-ray tube;
an outer insulation sandwiched between and electrically insulating the shielded x-ray tube and the shielded power supply from the enclosure;
the material composition of the power supply shield is different than a material composition of the outer insulation; and
the material composition of the x-ray tube shield is different than the material composition of the outer insulation.

3. The shielded x-ray source of claim 2 , wherein the x-ray tube shield is electrically insulative, the power supply shield is electrically insulative, the material composition of the x-ray tube shield is inorganic, the material composition of the x-ray tube insulation is organic, 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.

4. The shielded x-ray source of claim 3 , wherein:
a relative permittivity of the x-ray tube shield is greater than a relative permittivity of the outer insulation;
the relative permittivity of the outer insulation is greater than a relative permittivity of the x-ray tube insulation;
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.

5. The shielded x-ray source 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.

6. The shielded x-ray source 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 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.

7. The shielded x-ray source 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.

8. A shielded x-ray tube comprising:
an x-ray tube configured to emit x-rays;
an x-ray tube shield wrapping at least partially around the x-ray tube, the x-ray tube shield being electrically insulative;
the x-ray tube shield spaced apart from the x-ray tube by an arcuate gap; and
x-ray tube insulation separating the x-ray tube shield from the x-ray tube, the x-ray tube insulation comprising a solid, electrically-insulative material with a different material composition than a material composition of the x-ray tube shield.

9. The shielded x-ray tube of claim 8 , further comprising:
a power supply electrically coupled to the x-ray tube;
an enclosure at least partially surrounding the power supply and the x-ray tube;
an outer insulation sandwiched between and electrically insulating at least part of the x-ray tube and at least part of the power supply from the enclosure; and
a material composition of the x-ray tube shield is different than a material composition of the outer insulation.

10. The shielded x-ray tube of claim 8 , wherein relative permittivity of the x-ray tube shield is greater than relative permittivity of the x-ray tube insulation.

11. The shielded x-ray tube of claim 8 , wherein relative permittivity of the x-ray tube shield divided by relative permittivity of the x-ray tube insulation is ≥2.

12. The shielded x-ray tube of claim 8 , wherein a minimum thickness of the x-ray tube shield is ≥1 mm and maximum thickness of the x-ray tube shield is ≤5 mm.

13. The shielded x-ray tube of claim 8 , wherein an external surface of the x-ray tube shield is corrugated, an internal surface of the x-ray tube shield is corrugated, or both.

14. The shielded x-ray tube of claim 8 , further comprising:
an external surface of the x-ray tube shield is corrugated, defining a corrugated external surface;
a ridge and a furrow of the corrugated external surface extend in a continuous spiral from one open end of the x-ray tube shield to an opposite open end of the x-ray tube shield;
a coating on the ridge, extending in a continuous line of material on the continuous spiral;
electrical resistance from one end to an opposite end of the line of material is between 100 megaohms and 100,000 megaohms; and
the line of material is a voltage sensing resistor electrically-coupled across and configured for measurement of voltage across the x-ray tube, a voltage multiplier or both.

15. The shielded x-ray tube of claim 8 , wherein:
the x-ray tube shield has two open ends located opposite of each other;
the shielded x-ray tube further comprises a coating on a surface of the x-ray tube shield, the coating being a continuous layer;
electrical resistance of the coating is between 100 megaohms and 100,000 megaohms, where the electrical resistance of the coating is measured between the coating closest to one open end of the x-ray tube shield and the coating closest to the opposite open end of the x-ray tube shield;
the coating is a line of material wrapping multiple times around the x-ray tube shield, arranged in a serpentine pattern, or both; and
the coating is a voltage sensing resistor electrically-coupled across and configured for measurement of voltage across the x-ray tube, an x-ray tube, or both.

16. The shielded x-ray tube of claim 15 , wherein a length of the line of material is at least 20 times a shortest distance between the two open ends of the x-ray tube shield.

17. The shielded x-ray tube of claim 8 , wherein:
the x-ray tube shield has a conical frustum shape with two open ends including a wider end and a smaller end, the wider end being ≥1.2 times larger than the smaller end;
the wider end is closer to a location on the x-ray tube with a highest absolute value of voltage; and
the smaller end is closer to a location on the x-ray tube with a lowest absolute value of voltage.

18. A shielded power supply for an x-ray source, the shielded power supply comprising:
a voltage multiplier;
a power supply shield wrapping at least partially around the voltage multiplier, the power supply shield being electricall

Assignees

• Moxtek Inc

Inventors

• Hoffman David S
• Jones Vincent F
• Miller Eric

Classifications

• H01J2235/166

  against electromagnetic radiation · CPC title

• H05G1/06

  X-ray tube and at least part of the power supply apparatus being mounted within the same housing · CPC title

• H01J35/16 Primary

  Vessels; Containers; Shields associated therewith · CPC title

• H01J2235/165

  Shielding arrangements · CPC title