Transportable linear accelerator system and transportable neutron source equipped therewith

Patent metadata

Field	Value
Publication number	US-10098218-B2
Application number	US-201415324870-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

For the purpose of providing a transportable linear accelerator system which can restrain entering of losing ion beams deviated from a trajectory therefor, to thereby efficiently achieve reduction in radioactivity at low cost, and a transportable neutron source equipped therewith, a transportable linear accelerator system is configured to be provided with a beam chopper just before an inlet of a post-accelerator, thereby to cut off, from the proton beams pre-accelerated by a pre-accelerator, uncontrolled proton beams, and thus to radiate only the controlled proton beams to the post-accelerator, so that the proton beams are prevented from hitting an acceleration electrode, etc. of the post accelerator.

First claim

The invention claimed is:

1. A transportable neutron source, comprising:
a linear accelerator system, the linear accelerator system comprising:
a pre-accelerator that clusters and pre-accelerates proton beams generated by an ion source,
a beam chopper that cuts off, from the pre-accelerated proton beams, proton beams deviated from a trajectory therefor, to thereby cause only the proton beams controlled by the pre-accelerator to pass through the beam chopper, and
a post-accelerator that accelerates up to a given energy the proton beams having passed through the beam chopper;
a target part that introduces the proton beams from the transportable linear accelerator system to thereby generate neutron beams; and
a detector that captures the neutron beams after being radiated from the target part to an object and passing through the object.

2. The transportable neutron source according to claim 1 , wherein, when a plane perpendicular to a traveling direction Z of the pre-accelerated proton beams is defined separately by two axes of an X-axis and a Y-axis, the beam chopper comprises: a first slit that causes, among the pre-accelerated proton beams, only the proton beams existing within a specified distance along the X-axis from a beam-acceleration center axis, to pass therethrough; and a second slit that causes, among the proton beams having passed through the first slit, only the proton beam existing within a specified angle from the first slit with respect to the beam-acceleration center axis, to pass therethrough.

3. The transportable neutron source according to claim 2 , wherein the pre-accelerator and the post-accelerator are each a drift tube linear accelerator; a vacuum vessel of each of the pre-accelerator and the post-accelerator is formed of a central plate and a pair of semi-cylindrical tubes; and the central plate has a ridge, an acceleration electrode and a stem connecting the ridge with the acceleration electrode, that are made from a common block.

4. The transportable neutron source according to claim 3 , wherein the vacuum vessel has, in its cross-section perpendicular to the beam-acceleration center axis, an X-direction vessel inner diameter that is perpendicular to a center axis in a planar direction of the central plate which is a direction in which the stem extends, and that passes across the beam-acceleration center axis,
said X-direction vessel inner diameter being longer than a Y-direction vessel inner diameter that is parallel to the center axis in the planar direction.

5. The transportable neutron source according to claim 1 , wherein the pre-accelerator and the post-accelerator are connected to each other by way of a power divider, and the pre-accelerator or the post-accelerator is provided with a high-frequency amplifier that feeds power for accelerating the proton beams.

6. The transportable neutron source according to claim 2 , wherein the pre-accelerator and the post-accelerator are connected to each other by way of a power divider, and the pre-accelerator or the post-accelerator is provided with a high-frequency amplifier that feeds power for accelerating the proton beams.

7. The transportable neutron source according to claim 3 , wherein the pre-accelerator and the post-accelerator are connected to each other by way of a power divider, and the pre-accelerator or the post-accelerator is provided with a high-frequency amplifier that feeds power for accelerating the proton beams.

8. The transportable neutron source according to claim 4 , wherein the pre-accelerator and the post-accelerator are connected to each other by way of a power divider, and the pre-accelerator or the post-accelerator is provided with a high-frequency amplifier that feeds power for accelerating the proton beams.

9. The transportable neutron source according to claim 5 wherein the high-frequency amplifier is configured with a semiconductor element.

10. The transportable neutron source according to claim 6 , wherein the high-frequency amplifier is configured with a semiconductor element.

11. The transportable neutron source according to claim 7 , wherein the high-frequency amplifier is configured with a semiconductor element.

12. The transportable neutron source according to claim 8 , wherein the high-frequency amplifier is configured with a semiconductor element.

13. A linear accelerator system, comprising:
a pre-accelerator that clusters and pre-accelerates proton beams generated by an ion source, the pre-accelerator being a drift tube linear accelerator having a vacuum vessel comprising a central plate and a pair of semi-cylindrical tubes;
a beam chopper that cuts off, from the pre-accelerated proton beams, proton beams deviated from a trajectory therefor, to thereby cause only the proton beams controlled by the pre-accelerator to pass through the beam chopper; and
a post-accelerator that accelerates up to a given energy the proton beams having passed through the beam chopper, the post accelerator being a drift tube linear accelerator having a vacuum vessel comprising a central plate and a pair of semi-cylindrical tubes;
wherein, for each of the pre-accelerator and the post-accelerator: (i) the central plate has a ridge, an acceleration electrode and a stem connecting the ridge with the acceleration electrode, that are made from a common block, (ii) the semi-cylindrical tubes are provided on both sides of the center plate in a cross-sectional view, and (iii) the acceleration electrode of the central plate is fixed by screws from the atmospheric side of the vacuum vessel.

Assignees

• Mitsubishi Electric Corp

Inventors

• Yamamoto Kazuo
• Kawasaki Sadahiro
• Inoue Hiromitsu

Classifications

• H05H7/02

  Circuits or systems for supplying or feeding radio-frequency energy · CPC title

• H05H2007/002

  for modifying beam trajectory, e.g. gantries · CPC title

• G21K1/04

  using variable diaphragms, shutters, choppers · CPC title

• H05H7/22

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

• H05H7/001 Primary

  Arrangements for beam delivery or irradiation (irradiation systems per se G21K5/00) · CPC title