US-12623089-B2 - Radiotherapy device and microwave source thereof

Abstract

A microwave source used in the radiotherapy device can be provided. The microwave source may include an anode block and one or more cathodes. The cathode of the microwave source may include a cathode support element having a plurality of slots. The plurality of slots can be axially around a circumference of the cathode support element. The microwave source may include a cathode heater including at least one filament. A first part of the at least one filament may be wound around the cathode support element along a first direction and received by a first portion of the plurality of slots, and a second part of the at least one filament may be wound around the cathode support element along a second direction and received by a second portion of the plurality of slots.

Inventors

• Peng Wang

Assignees

• SHANGHAI UNITED IMAGING HEALTHCARE CO., LTD.

Dates

Publication Date

20260512

Application Date

20220622

Claims (20)

1. 1 . A microwave source, comprising: an anode block; and multiple cathodes, wherein when an individual cathode of the multiple cathodes is removably positioned in a center of the anode block, microwaves having a specific frequency are generated in response to an occurrence of a resonance effect caused by the anode block and the cathode.
2. 2 . The microwave source of claim 1 , wherein diameters of at least two of the multiple cathodes are different.
3. 3 . The microwave source of claim 1 , wherein each of the multiple cathodes includes: a cathode support element having a plurality of slots, the plurality of slots being axially around a circumference of the cathode support element; and a cathode heater including at least one filament, wherein a first part of the at least one filament is wound around the cathode support element along a first direction and received by a first portion of the plurality of slots, and a second part of the at least one filament is wound around the cathode support element along a second direction and received by a second portion of the plurality of slots.
4. 4 . The microwave source of claim 3 , wherein the first part of the at least one filament and the second part of the at least one filament are substantially parallel, and when the at least one filament is powered by a power source, directions of respective current flows of the first part and the second part of the at least one filament are inversed.
5. 5 . The microwave source of claim 3 , wherein the first portion of the plurality of slots and the second portion of the plurality of slots are spaced axially around the circumference of the cathode support element.
6. 6 . The microwave source of claim 5 , wherein the diameter of the filament is in a range of 0.4 mm to 0.8 mm.
7. 7 . The microwave source of claim 3 , wherein a depth of a slot of the plurality of slots is greater than or equal to a diameter of one of the at least one filament, and a width of the slot is greater than or equal to the diameter of the filament.
8. 8 . The microwave source of claim 3 , wherein the at least one filament is made of a high-melting-point and conductive material.
9. 9 . The microwave source of claim 8 , wherein the at least one filament includes at least one of tungsten, molybdenum, rhenium, or iridium.
10. 10 . The microwave source of claim 3 , wherein the cathode support element is made of an insulative material.
11. 11 . The microwave source of claim 3 , further comprising: a thermionic emitter configured to release electrons when the thermionic emitter is heated by the cathode heater.
12. 12 . The microwave source of claim 3 , wherein the first part of the at least one filament is electrically connected to the second part of the at least one filament.
13. 13 . The microwave source of claim 3 , wherein a value of a current flow of the first part is the same as a value of a current flow of the second part.
14. 14 . The microwave source of claim 3 , wherein the plurality of slots are formed through a continuous spiral groove radially around the circumference of the cathode support element.
15. 15 . The microwave source of claim 1 , further comprising: a connector configured to connect each of the multiple cathodes.
16. 16 . The microwave source of claim 15 , further comprising: a limiting member connected to an end of the connector and configured to move the multiple cathodes.
17. 17 . The microwave source of claim 16 , wherein the limiting member is moved along a guiding slot such that one of the multiple cathodes is positioned in the center of the anode block.
18. 18 . A radiotherapy device including a linear accelerator, the linear accelerator comprising: an electron generator configured to emit electrons along a beam path; the microwave source according to claim 14 ; and an accelerator tube configured to accelerate the electrons emitted by the electron generator in response to the microwaves having the specific frequency.
19. 19 . A cathode, comprising: a cathode support element having a slot, the slot being axially around a circumference of the cathode support element; a cathode heater, and a thermionic emitter, wherein the thermionic emitter includes a hollow cylinder of emissive material, and the cathode support element is disposed in a hollow space of the thermionic emitter.
20. 20 . The cathode of claim 19 , wherein the cathode heater is fixed on the cathode support element in a spiral configuration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2019/127480, filed on Dec. 23, 2019, the content of which is hereby incorporated by reference. TECHNICAL FIELD This disclosure generally relates to a radiotherapy device, and more particularly, to a microwave source used in the radiotherapy device. BACKGROUND Radiation therapy is widely used in cancer treatment and is also beneficial to several other health conditions. A radiotherapy device (e.g., a linear accelerator) is often utilized to perform the radiation therapy. In the radiotherapy device, a microwave source, composed of an anode and a cathode, is configured to produce microwave pulses (or radio frequency pulses) for controlling the generation of radiation beams (e.g., X-rays). The microwave source is an important component for the radiotherapy device. In some cases, the cathode of the microwave source breaks easily due to frequent deformation of the cathode heater, and such malfunction often affects the normal use of the radiotherapy device. Therefore, it is desirable to develop a high-quality microwave source used in the radiotherapy device. SUMMARY In a first aspect of the present disclosure, a cathode of a microwave source may be provided. The cathode may include a cathode support element having a plurality of slots and a cathode heater including at least one filament. The plurality of slots may be axially around a circumference of the cathode support element. A first part of the at least one filament may be wound around the cathode support element along a first direction and received by a first portion of the plurality of slots, and a second part of the at least one filament may be wound around the cathode support element along a second direction and received by a second portion of the plurality of slots. In some embodiments, the first part of the at least one filament and the second part of the at least one filament may be substantially parallel, and when the at least one filament is powered by a power source, directions of respective current flows of the first part and the second part of the at least one filament may be inversed. In some embodiments, the first portion of the plurality of slots and the second portion of the plurality of slots may be spaced axially around the circumference of the cathode support element. In some embodiments, a depth of a slot of the plurality of slots may be greater than or equal to a diameter of one of the at least one filament, and a width of the slot may be greater than or equal to the diameter of the filament. In some embodiments, the diameter of the filament may be in a range of 0.4 mm to 0.8 mm. In some embodiments, the at least one filament may be made of a high-melting-point and conductive material. In some embodiments, the at least one filament may include at least one of tungsten, molybdenum, rhenium, or iridium. In some embodiments, the cathode support element may be made of an insulative material. In some embodiments, the cathode support element may include at least one of plastic, rubber, glass, ceramic. In some embodiments, the cathode may include a thermionic emitter configured to release electrons when the thermionic emitter is heated by the cathode heater. In a second aspect of the present disclosure, a microwave source may be provided. The microwave source may include an anode block and a cathode centered in the anode block. In some embodiments, the cathode may include may include a cathode support element having a plurality of slots and a cathode heater including at least one filament. The plurality of slots may be axially around a circumference of the cathode support element. A first part of the at least one filament may be wound around the cathode support element along a first direction and received by a first portion of the plurality of slots, and a second part of the at least one filament may be wound around the cathode support element along a second direction and received by a second portion of the plurality of slots. In some embodiments, the first part of the at least one filament and the second part of the at least one filament may be substantially parallel, and when the at least one filament is powered by a power source, directions of respective current flows of the first part and the second part of the at least one filament may be inversed. In a third aspect of the present disclosure, a radiotherapy device can be provided. The radiotherapy device may include a linear accelerator. The linear accelerator may include an electron generator configured to emit electrons along a beam path, a microwave source configured to generate microwaves and an accelerator tube configured to accelerate the electrons emitted by the electron generator in response to the microwaves. The microwave source may include an anode block and a cathode centered in the anode block. The cathode may include may include a cathode support element having a pl