# US 2019/0318902 A1 · X-ray tube

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- Number: US 2019/0318902 A1
- Document ID: US20190318902A1
- Status: Published application
- Kind: A1
- Application number: 16/380,187
- Filed: 2019-04-10
- Published: 2019-10-17
- Earliest claimed: 2018-04-12
- Assignees: Hamamatsu Photonics K.K.
- Applicants: Hamamatsu Photonics K.K.
- Inventors: Atsushi ISHII; Tutomu INAZURU
- Web page: https://patentgrep.com/patent/US20190318902A1

## CPC

- H01J 35/16: Vessels; Containers; Shields associated therewith
- H05G 1/06: X-ray tube and at least part of the power supply apparatus being mounted within the same housing
- H01J 35/112: {Non-rotating anodes (H01J35/12 takes precedence)}
- H01J 2235/165: Shielding arrangements
- H05G 1/025: {Means for cooling the X-ray tube or the generator}
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321)

## Abstract

An X-ray tube includes an electron gun, a target that generates X-rays, and a vacuum housing that accommodates the electron gun and the target. The vacuum housing has a metal portion having an X-ray emission window, and an insulation valve connected to the metal portion. The metal portion has a cylinder portion in which the X-ray emission window is provided and which surrounds a tube axis of the vacuum housing, and a tapered portion which is connected to an end portion of the cylinder portion, surrounds the tube axis, and protrudes such that a connection part between the metal portion and an insulation valve is covered. The tapered portion has a shape increased in diameter such that a separation distance between a distal end portion and the tube axis is longer than a separation distance between a base end portion and the tube axis.

## Claims

### Claim 1

An X-ray tube comprising:
an electron gun that emits electrons;
a target that generates X-rays when electrons emitted from the electron gun are incident on the target; and
a vacuum housing that accommodates the electron gun and the target,
wherein the vacuum housing has a metal portion which has an X-ray emission window emitting X-rays to the outside and a valve portion which is formed of an insulating material and is connected to the metal portion,
wherein the metal portion has a first part in which the X-ray emission window is provided and which surrounds a central axis of the vacuum housing, and a second part which is connected to an end portion of the first part on the valve portion side, surrounds the central axis, and protrudes such that a connection part between the metal portion and the valve portion is covered, and
wherein the second part has a shape increased in diameter such that a separation distance between a distal end portion on a side opposite to a base end portion connected to the first part and the central axis is longer than a separation distance between the base end portion and the central axis.

### Claim 2 (depends on 1)

The X-ray tube according to claim 1,
wherein the second part has a protrusion portion which has the distal end portion and of which the entirety protrudes into an inner space of the vacuum housing, and a base portion which has the base end portion and of which at least a part of an outer surface is exposed to the outside, and
wherein inner wall surfaces of the protrusion portion and the base portion are increased in diameter such that the separation distance between the distal end portion and the central axis is longer than the separation distance between the base end portion and the central axis.

### Claim 3 (depends on 1)

The X-ray tube according to claim 1,
wherein an inner wall surface of the second part has a tapered shape in which a separation distance between the inner wall surface and the central axis increases linearly from the base end portion toward the distal end portion.

### Claim 4 (depends on 1)

The X-ray tube according to claim 1,
wherein an inner wall surface of the second part has a curved shape in which a separation distance between the inner wall surface and the central axis increases continuously from the base end portion toward the distal end portion.

### Claim 5 (depends on 1)

The X-ray tube according to claim 1,
wherein an inner wall surface of the second part has a stepped shape in which a separation distance between the inner wall surface and the central axis increases step by step from the base end portion toward the distal end portion.

### Claim 6 (depends on 1)

The X-ray tube according to claim 1,
wherein an anode having the target is disposed while extending along the central axis.

### Claim 7 (depends on 1)

The X-ray tube according to claim 1,
wherein the electron gun is disposed while extending along the central axis.