Hybrid standing wave linear accelerators providing accelerated charged particles or radiation beams

Patent metadata

Field	Value
Publication number	US-10015874-B2
Application number	US-201715456057-A
Country	US
Kind code	B2
Filing date	Mar 10, 2017
Priority date	Mar 11, 2016
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A hybrid linear accelerator is disclosed comprising a standing wave linear accelerator section (“SW section”) followed by a travelling wave linear accelerator section (“TW section”). In one example, RF power is provided to the TW section and power not used by the TW section is provided to the SW section via a waveguide. An RF switch, an RF phase adjuster, and/or an RF power adjuster is provided along the waveguide to change the energy and/or phase of the RF power provided to the SW section. In another example, RF power is provided to both the SW section and the TW section, and RF power not used by the TW section is provided to the SW section, via an RF switch, an RF phase adjuster, and/or an RF power. In another example, an RF load is matched to the output of the TW section by an RF switch.

First claim

What is claimed is:

1. A hybrid linear accelerator comprising:
a source of charged particles configured to provide an input beam of charged particles;
a standing wave linear accelerator section configured to receive the input beam of charged particles and accelerate the charged particles, the standing wave linear accelerator section providing an intermediate beam of accelerated electrons;
a traveling wave linear accelerator section configured to receive the intermediate beam of accelerated electrons, and to further increase the momentum and energy of the intermediate beam of accelerated electrons, the traveling wave linear accelerator section providing an output beam of charged particles;
a drift tube configured to provide a path for passage of the intermediate beam from the standing wave linear accelerator section to the traveling wave linear accelerator section, the drift tube configured to RF decouple the standing wave linear accelerator section from the traveling wave linear accelerator section to further increase the momentum and energy of the intermediate beam;
an RF source configured to provide RF power to the traveling wave linear accelerator section; and
a first RF waveguide having an input coupled to an output of the traveling wave linear accelerator section and an output coupled to an input of the standing wave linear accelerator section;
wherein RF power remaining after attenuation in the traveling wave linear accelerator section is fed to the standing wave linear accelerator section to accelerate the charged particles.

2. The hybrid linear accelerator of claim 1 , further comprising:
a switch, a phase shifter, and/or a power adjuster along the first RF waveguide, to change the power and/or phase of the RF power provided to the standing linear accelerator section.

3. The hybrid linear accelerator of claim 2 , wherein the phase shifter, and/or the power adjuster are configured to provide energy regulation of the output beam of electrons of from about 0.5 MeV to a maximum linear accelerator energy.

4. The hybrid linear accelerator of claim 1 , wherein the standing wave linear accelerator section is configured in the form of a buncher.

5. The hybrid linear accelerator of claim 1 , wherein the source of charged particles comprises an electron gun configured to provide an input beam of electrons.

6. The hybrid linear accelerator of claim 1 , further comprising.
a first external magnetic system cooperative with the standing wave linear accelerator section; and/or
a second external magnetic system cooperative with the traveling wave linear accelerator section.

7. The hybrid linear accelerator of claim 1 , further comprising:
a second RF waveguide between the RF source and traveling wave linear accelerator section configured to provide RF power from the RF source to the traveling wave linear accelerator section; and
a high power circulator along the second RF waveguide to prevent reflected RF power from propagating back to the RF source; and/or
a low power circulator along the first RF waveguide to prevent reflected RF power from propagating back to the traveling wave linear accelerator section.

8. The hybrid linear accelerator of claim 1 , further comprising at least one of:
an charged particle beam window, and a conversion target for producing Bremsstrahlung radiation.

9. A hybrid linear accelerator comprising:
a source of charged particles;
a standing wave linear accelerator section configured to receive the input beam of electrons and accelerate the charged particles, the standing wave linear accelerator section providing an intermediate beam of accelerated charged particles;
a traveling wave linear accelerator section configured to receive the intermediate beam of accelerated charged particles, and to further increase the momentum and energy of the accelerated electrons, the traveling wave linear accelerator section providing an output beam of charged particles;
a drift tube configured to provide RF decoupling between the standing wave linear accelerator section and the traveling wave linear accelerator section, while also permitting transit of the intermediate beam of accelerated electrons from the standing wave linear accelerator section to the traveling wave linear accelerator section;
an RF power source; and
an RF splitter configured to receive RF power from the RF power source and to bifurcate the RF power into a first portion of RF power to be provided to the standing wave linear accelerator section and a second portion of RF power to be provided to the traveling wave linear accelerator section.

10. The hybrid linear accelerator of claim 9 , further comprising:
an RF switch, an RF phase shifter, and an RF power adjuster between the traveling wave linear accelerator section and the RF splitter, the RF switch, the RF phase shifter, and the RF power adjuster being configured to feed the standing wave standing wave linear accelerator section RF power not used by the traveling wave linear accelerator section, and/or to change a phase relationship between the standing wave linear accelerator section and the traveling wave linear accelerator section.

11. The hybrid linear accelerator of claim 10 , wherein the switch, the phase shifter, and/or the power adjuster are configured to provide energy regulation from about 0.5MeV to maximum linear accelerator energy.

12. The hybrid linear accelerator of claim 9 , wherein the standing wave linear accelerator section is configured in the form of a buncher.

13. The hybrid linear accelerator of claim 9 , wherein:
the source of charged particles comprises an electron gun configured to provide an input beam of electrons.

14. The hybrid linear accelerator of claim 9 , further comprising:
a first external magnetic system cooperative with the standing wave linear accelerator section; and/or
a second external magnetic system cooperative with the traveling wave linear accelerator section.

15. The hybrid linear accelerator of claim 9 , further comprising:
an RF waveguide between the RF source and RF splitter, to provide RF power to the RF splitter; and
a high power circulator along the RF waveguide to prevent reflected RF power from propagating back to the RF source.

16. The hybrid linear accelerator of claim 9 , further comprising:
a matched RF load coupled to the traveling wave linear accelerator section to absorb RF power remaining after acceleration in the traveling wave linear accelerator section.

17. The hybrid linear accelerator of claim 9 , further comprising at least one of:
an charged particle beam window, and a conversion target for producing Bremsstrahlung radiation.

18. A hybrid linear accelerator comprising:
a source of charged particles configured to provide an input beam of electrons;
a standing wave linear accelerator section configured to receive the input beam of charged particles and accelerate the charged particles, the standing wave linear accelerator section providing an intermediate beam of accelerated charged particles;
a traveling wave linear accelerator section configured to receive the intermediate beam of accelerated charged particles, and to further increase the momentum and energy of the accelerated charged particles, the traveling wave linear accelerator section having an output;
an RF coupler configured to provide RF coupling between the standing wave linear accelerator section and the traveling wave linear accelerator section and to allow transit of the intermediate beam of accelerated electrons from the standing wave linear accelerator sect

Assignees

• Varex Imaging Corp

Inventors

• Mishin Andrey

Classifications

• H05H9/02 Primary

  Travelling-wave linear accelerators {(travelling-wave tubes H01J25/34)} · CPC title

• H05H7/04

  Magnet systems {, e.g. undulators, wigglers (free-electron laser H01S3/0903)}; Energisation thereof · CPC title

• H05H7/22

  Details of linear accelerators, e.g. drift tubes (H05H7/02 - H05H7/20 take precedence) · CPC title

• H05H2007/025

  Radiofrequency systems · CPC title

• H05H9/04

  Standing-wave linear accelerators · CPC title