X-ray tube integral heatsink
Improved heat transfer from an x-ray tube can be accomplished with a heatsink surrounding at least part of an x-ray tube. The heatsink can be electrically connected to an anode of the x-ray tube and can be an electrical current path. The heatsink can include a plurality of protrusions extending radially outward from the x-ray tube and can be a single, integral substance extending from an inner-surface of the heatsink to a distal-end of the protrusions.
1. An x-ray source comprising:
a. an x-ray tube including a cathode, an anode, and an enclosure, wherein:
i. the enclosure is electrically-insulative;
ii. the cathode and the anode are electrically insulated from each other;
iii. the cathode and the anode are attached to the enclosure;
iv. the cathode includes an electron-emitter capable of emitting electrons towards the anode; and
v. the anode is capable of emitting x-rays in response to impinging electrons from the electron-emitter;
b. a heatsink, wherein the heatsink:
i. is electrically conductive;
ii. is electrically-coupled to the anode and electrically-insulated from the cathode; and
iii. includes a plurality of protrusions extending radially outward from the x-ray tube, the protrusions configured to increase heat transfer away from the x-ray tube; and
c. electrically-insulative material encircling and adjoining an outer-surface of the enclosure and adjoining an inner-surface of the heatsink.
2. The x-ray source of claim 1 , wherein a radial path from the outer-surface of the enclosure to the inner-surface of the heatsink passes only through the electrically-insulative material.
3. The x-ray source of claim 2 , wherein the electrically-insulative material includes at least two layers of different substances.
4. The x-ray source of claim 1 , wherein the electrically-insulative material includes a region with a thermal conductivity of at least 0.8 W/(m*K).
5. The x-ray source of claim 1 , further comprising a power supply, wherein:
a. the power supply is configured to provide a voltage between the electron-emitter and the anode to at least assist in causing the electrons to emit from the cathode to the anode;
b. the power supply is electrically-coupled to the heatsink; and
c. the x-ray source is configured for at least 90% of electrons flowing from the anode to a ground or to the power supply to pass through the heatsink.
6. The x-ray source of claim 1 , wherein a resistance between the anode and the heatsink is less than 0.01 ohms.
7. The x-ray source of claim 1 , wherein a maximum outside diameter of the heatsink is less than 40 millimeters.
8. The x-ray source of claim 1 , wherein the heatsink is a single, integral substance extending from an inner-surface of the heatsink to a distal-end of the protrusions.
9. The x-ray source of claim 1 , wherein/further comprising . . .
the cathode is located at one end of a longitudinal axis extending through a hollow core of the enclosure and the anode is located at an opposite end of the longitudinal axis; and
the heatsink encircles the longitudinal axis and the x-ray tube about the longitudinal axis.
10. The x-ray source of claim 1 , wherein the electrically-insulative material includes a region with an electrical volume resistivity of at least 1×10 16 ohm*cm.
11. The x-ray source of claim 1 , wherein:
the plurality of protrusions include a plurality of elongated ribs;
a length of the plurality of elongated ribs extends substantially-parallel to a direction of electron flow from the cathode to the anode; and
the plurality of elongated ribs include at least 10 ribs having a length at least as long as a length of the x-ray tube.
12. The x-ray source of claim 1 , wherein at least a portion of an outer surface of the heatsink has an electrical volume resistivity of at least 10 8 ohm*cm.
13. The x-ray source of claim 1 , wherein the electrically-insulative material completely fills an annular portion of an annular gap between the heatsink and the enclosure.
14. The x-ray source of claim 1 , wherein the heatsink is directly electrically-coupled to the anode by an electrically-conductive solder.
15. The x-ray source of claim 1 , wherein the heatsink is directly electrically-coupled to the anode by a weld.
16. The x-ray source of claim 1 , wherein the heatsink is directly electrically-coupled to the anode by epoxy, adhesive, or both.
17. The x-ray source of claim 1 , wherein the heatsink is directly electrically-coupled to the anode by press-fit.
18. The x-ray source of claim 1 , wherein the electrically-insulative material has thermal conductivity of at least 1.2 W/(m*K).
19. The x-ray source of claim 5 , wherein the power supply is electrically coupled to the heatsink and the x-ray tube by a cable, the cable having a length of at least two meters.
20. The x-ray source of claim 5 , wherein the x-ray source is configured for at least 99% of electrons flowing from the anode to a ground or to the power supply to pass through the heatsink.