X-ray tube anode with integrated collimator
A collimator for an x-ray tube can be a monolithic, integral structure. The collimator can include a proximal-end closest to a cathode and a distal-end farthest from the cathode. The proximal-end can adjoin a vacuum inside of the x-ray tube. The distal-end can adjoin the air. The collimator can include an aperture extending therethrough. An x-ray window can be mounted across the aperture. The aperture can include a collimation-region between the x-ray window and the distal-end, and a drift-region between the x-ray window and the proximal-end. X-rays can be generated inside of the collimator.
1 . An x-ray tube comprising:
a cathode and an anode electrically insulated from one another, the cathode configured to emit electrons towards a target material of the anode, and the target material configured to emit x-rays out of the x-ray tube in response to impinging electrons from the cathode;
an electrically insulative device attached to the anode and the cathode, and electrically insulating the anode from the cathode;
a collimator (a) that is a monolithic, integral structure, (b) that has an aperture extending therethrough, and (c) that is configured to collimate the x-rays;
an x-ray window mounted across the aperture, the aperture aimed for x-rays to emit through the aperture, through the x-ray window, and out of the x-ray tube;
the collimator includes a proximal-end closest to the cathode and a distal-end farthest from the cathode, the proximal-end adjoins a vacuum inside of the x-ray tube and the distal-end adjoins air;
a ring encircling the collimator; and
the ring is located between and attached to the collimator and to the electrically insulative device.
2 . The x-ray tube of claim 1 , further comprising:
a first hermetical seal between the collimator and the ring;
a second hermetical seal between the ring and the electrically insulative device; and
no hermetical seal directly between the collimator and the electrically insulative device.
3 . The x-ray tube of claim 1 , wherein the aperture includes a collimation-region between the x-ray window and the distal-end, and a diameter of the collimation-region increases as distance from the x-ray window increases.
4 . The x-ray tube of claim 3 , wherein an angle of walls of the collimation-region is at least 30° and not greater than 60°, the angle measured between a line aligned with a face of the walls of the collimation-region and a face of the x-ray window.
5 . The x-ray tube of claim 1 , wherein:
the aperture includes a collimation-region between the x-ray window and the distal-end; and
0.5≤ 17 L/ 17 d , where 17 L is a shortest length of the collimation-region between the x-ray window and the distal-end, and 17 d is a diameter of the collimation-region, measured perpendicular to a longitudinal axis of the x-ray tube.
6 . The x-ray tube of claim 5 , wherein 17 L/ 17 d ≤5.
7 . The x-ray tube of claim 1 , wherein:
the aperture includes a collimation-region between the x-ray window and the distal-end; and
≥50% of the collimation-region protrudes outward from any other solid portion of the x-ray tube as a farthest protruding solid object at an x-ray emission end of the x-ray tube.
8 . The x-ray tube of claim 1 , wherein:
the aperture includes a collimation-region between the x-ray window and the distal-end;
the aperture includes a drift-region between the x-ray window and the proximal-end; and
0.2≤ 18 L/ 17 L≤1.6, where 17 L is a shortest length of the collimation-region between the x-ray window and the distal-end, and 18 L is a shortest length of the drift-region between the x-ray window and the proximal-end.
9 . The x-ray tube of claim 1 , wherein:
a longitudinal-axis of the x-ray tube extends from an electron-emitter at the cathode to a target material at the anode; and
the x-ray window is located at least 2 mm beyond a farthest end of the electrically insulative device, measured parallel to the longitudinal-axis.
10 . The x-ray tube of claim 1 , wherein the anode consists essentially of the collimator, x-ray window, an adhesive for mounting the x-ray window, and the target material.
11 . The x-ray tube of claim 1 , wherein the x-ray window forms a hermetic seal and separates the vacuum from the air.
12 . The x-ray tube of claim 1 , wherein at least one element in the collimator has an atomic number ≥74.
13 . The x-ray tube of claim 1 , wherein ≥80 weight percent of elements in the collimator have an atomic number ≥74.
14 . An x-ray tube comprising:
a cathode and an anode electrically insulated from one another, the cathode configured to emit electrons towards a target material of the anode, and the target material configured to emit x-rays out of the x-ray tube in response to impinging electrons from the cathode;
an electrically insulative device attached to the anode and the cathode, and electrically insulating the anode from the cathode;
a collimator (a) that is a monolithic, integral structure, (b) that has an aperture extending therethrough, and (c) that is configured to collimate the x-rays;
an x-ray window mounted across the aperture, the aperture aimed for x-rays to emit through the aperture, through the x-ray window, and out of the x-ray tube;
the collimator includes a proximal-end closest to the cathode and a distal-end farthest from the cathode, the proximal-end adjoins a vacuum inside of the x-ray tube and the distal-end adjoins air; and
the aperture includes a collimation-region between the x-ray window and the distal-end.
15 . The x-ray tube of claim 14 , wherein a diameter of the collimation-region increases as distance from the x-ray window increases.
16 . The x-ray tube of claim 15 , wherein an angle of walls of the collimation-region is at least 30° and not greater than 60°, the angle measured between a line aligned with a face of the walls of the collimation-region and a face of the x-ray window.
17 . The x-ray tube of claim 14 , wherein 0.5≤ 17 L/ 17 d , where 17 L is a shortest length of the collimation-region between the x-ray window and the distal-end, and 17 d is a diameter of the collimation-region, measured perpendicular to a longitudinal axis of the x-ray tube.
18 . The x-ray tube of claim 17 , wherein 17 L/ 17 d ≤5.
19 . The x-ray tube of claim 14 , wherein ≥50% of the collimation-region protrudes outward from any other solid portion of the x-ray tube as a farthest protruding solid object at an x-ray emission end of the x-ray tube.
20 . The x-ray tube of claim 14 , wherein:
the aperture includes a drift-region between the x-ray window and the proximal-end; and
0.2≤ 18 L/ 17 L≤1.6, where 17 L is a shortest length of the collimation-region between the x-ray window and the distal-end, and 18 L is a shortest length of the drift-region between the x-ray window and the proximal-end.