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:
an x-ray tube including a cathode, an anode, and an enclosure; the enclosure being electrically-insulative; the cathode and the anode being electrically insulated from each other and attached to the enclosure; the cathode located at one end of a longitudinal axis extending through a hollow core of the enclosure and the anode located at an opposite end of the longitudinal axis; the cathode having an electron-emitter capable of emitting electrons towards the anode; and the anode capable of emitting x-rays in response to impinging electrons from the electron-emitter;
a heatsink encircling the longitudinal axis and the x-ray tube about the longitudinal axis; being electrically conductive and electrically-coupled to the anode and electrically-insulated from the cathode; including 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 having at least a portion of an outer surface with an electrical volume resistivity of at least 10 8 ohm*cm; and
an electrically-insulative material encircling and adjoining an outer-surface of the enclosure and adjoining an inner-surface of the heatsink, including a region with a thermal conductivity of at least 0.8 W/(m*K), including a region with an electrical volume resistivity of at least 1×10 16 ohm*cm, filling an annular portion of an annular gap between the heatsink and the enclosure, and at least partially separating the heatsink from the enclosure; and
a radial path from the outer-surface of the enclosure to the inner-surface of the heatsink passing only through the electrically-insulative material.
2. The x-ray source of claim 1 , wherein the electrically-insulative material includes polyether ether ketone.
3. 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.
4. The x-ray source of claim 1 , wherein the plurality of protrusions include at least 10 elongated ribs, a length of the elongated ribs extends substantially-parallel to a direction of electron flow from the cathode to the anode, and the elongated ribs have a length at least as long as a length of the x-ray tube.
5. An x-ray source comprising:
an x-ray tube including a cathode, an anode, and an enclosure, the enclosure being electrically-insulative, the cathode and the anode being electrically insulated from each other and attached to the enclosure, the cathode located at one end of a longitudinal axis extending through a hollow core of the enclosure and the anode located at an opposite end of the longitudinal axis, the cathode having an electron-emitter capable of emitting electrons towards the anode, and the anode capable of emitting x-rays in response to impinging electrons from the electron-emitter;
a heatsink encircling the longitudinal axis and the x-ray tube about the longitudinal axis; being electrically conductive, electrically-coupled to the anode, and electrically-insulated from the cathode; and including 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;
an electrically-insulative material encircling and adjoining an outer-surface of the enclosure and adjoining an inner-surface of the heatsink; and
a radial path from the outer-surface of the enclosure to the inner-surface of the heatsink passing only through the electrically-insulative material.
6. The x-ray source of claim 5 , wherein the heatsink is a single, integral substance extending from an inner-surface of the heatsink to a distal-end of the protrusions.
7. The x-ray source of claim 5 , further comprising a power supply, the x-ray source configured to cause at least 99% of electrons flowing from the cathode to the anode to pass from the anode through the heatsink to a ground or to the power supply.
8. 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.
9. The x-ray source of claim 5 , wherein the electrically-insulative material includes at least two layers of different substances.
10. The x-ray source of claim 9 , further comprising:
the electrically-insulative material including a solid cylinder around the x-ray tube and extending beyond a distal-end of the cathode around wires connecting to the electron-emitter;
the electrically-insulative material including a second layer of electrically-insulative material inside the solid cylinder and around the wires; and
a radial path from the outer-surface of the enclosure to the inner-surface of the heatsink passes through the solid cylinder and the second layer of electrically-insulative material.
11. The x-ray source of claim 10 , wherein the solid cylinder includes polyether ether ketone.
12. The x-ray source of claim 10 , wherein one of the solid cylinder or the second layer of electrically-insulative material has a higher electrical resistivity and the other of the solid cylinder or the second layer of electrically-insulative material has a higher thermal conductivity.
13. The x-ray source of claim 5 , wherein the electrically-insulative material includes a region with a thermal conductivity of at least 0.8 W/(m*K) and a region with an electrical volume resistivity of at least 1×10 16 ohm*cm.
14. The x-ray source of claim 5 , wherein the plurality of protrusions include at least 10 elongated ribs, a length of the elongated ribs extends substantially-parallel to a direction of electron flow from the cathode to the anode, and the elongated ribs have a length at least as long as a length of the x-ray tube.
15. The x-ray source of claim 5 , wherein at least a portion of an outer surface of the heatsink has an electrical volume resistivity of at least 10 8 ohm*cm.
16. An x-ray source comprising:
an x-ray tube including a cathode and an anode being electrically insulated from each other, the cathode including an electron-emitter capable of emitting electrons towards the anode, and the anode capable of emitting x-rays in response to impinging electrons from the electron-emitter;
a heatsink being electrically conductive; being directly electrically-coupled to the anode by an electrically-conductive solder, weld, epoxy, adhesive, press-fit, or combinations thereof; being electrically-insulated from the cathode; and including at least 10 elongated ribs extending radially outward from the x-ray tube;
the elongated ribs configured to increase heat transfer away from the x-ray tube, having a length extending substantially-parallel to a direction of electron-flow from the cathode to the anode, and having a length at least as long as a length of the x-ray tube; and
a power supply electrically-coupled to the heatsink, electrically-coupled to the x-ray tube by a cable having a length of at least two meters, and configured to cause electrons to flow from the cathode to the anode then from the anode through the heatsink.
17. The x-ray source of claim 16 , 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.
18. The x-ray source of claim 16 , further comprising:
an electrically-insulative enclosure attached to the cathode and the anode, the cathode located at one end of a longitudinal axis extending through a hollow core of the enclosure and the anode located at an opposite end of the longitudinal axis; and
an electrically-insulative material filling an annular portion of an annular gap between the heatsink and the enclosure and at least partially separating the heatsink from the enclosure.
19. The x-ray source of claim 18 , wherein the electrically-insulative material includes at least two layers of different substances, one of the two layers has a higher electrical resistivity than the other and the other of the two layers has a higher thermal conductivity.
20. The x-ray source of claim 18 , wherein the electrically-insulative material includes a region with a thermal conductivity of at least 0.8 W/(m*K) and a region with an electrical volume resistivity of at least 1×10 16 ohm*cm.