Electromagnetic wave generator

• US 20060249685A1
• Filed: 04/20/2006
• Published: 11/09/2006
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubushi Denki Kabushiki Kaisha
• Inventors: Tanaka, Hirofumi
• Granted Patent: US 7,310,409 B2
• Time in Patent Office: Days
• US Class Current: 250/397
• CPC Class Codes: H01J 2235/08 Targets (anodes) and X-ray converters
• CPC Class Codes: H05G 2/00 Apparatus or processes specially adapted for producing X-rays, not involving X-ray tubes, e.g. involving generation of a plasma X-ray lasers H01S4/00
• CPC Class Codes: H05H 11/00 Magnetic induction accelerators, e.g. betatrons
• CPC Class Codes: H05H 6/00 Targets for producing nuclear reactions supports for targets or objects to be irradiated G21K5/08 ; preparation of tritium C01B4/00; targets, e.g. pellets for fusion reactions by laser or charged particles beam injection H05H1/22

Abstract

A compact and low-cost electromagnetic wave generator in which X-rays having high intensity can be generated and the energy of generated X-rays can rapidly be switched. In an electromagnetic wave generator including a circular accelerator, a deflection electromagnet incorporated in the circular accelerator focuses injected and accelerated electrons, The circular accelerator produces stable electron closed orbits in a region with a predetermined width in the radial direction of the accelerator that are stable during injection and acceleration of electron. A target is arranged across the stable electron closed orbits and a collision region, where a circulating electron beam collides with the target and a non-collision region where a circulating electron beam does not collide with the target produced. Through control of respective patterns of changes with time in the deflection magnetic field, a given electron closed orbit is shifted between the collision and the non-collision regions, thereby generating X-rays.

Claims

1. An electromagnetic wave generator including a circular accelerator, the circular accelerator comprising:

an electron generator for generating electrons;

an injector for injecting electrons from the electron generator;

an accelerator for accelerating the injected electrons;

a deflection electromagnet for generating a deflection magnetic field to deflect the injected electrons and accelerated electrons; and

a target with which the accelerated electrons are made to collide, whereby electromagnetic waves are generated, wherein

deflection electromagnet has a shape focusing injected electrons or accelerated electrons,

the circular accelerator has stable electron closed orbits that, through the deflection electromagnet focusing of the circular accelerator, are situated in a region with a predetermined width in a radial direction, the electron closed orbits been stable during step and an acceleration step,

the target is arranged across the stable electron closed orbits and, in accordance with the arrangement of the target, so that a collision region, where a circulating electron beam collides with the targets and at least one non-collision region that is adjacent to the collision region and in which a circulating electron beam does not collide with the targets are located, within the stable electron closed orbits, and

through control of respective patterns of changes with time in a deflection magnetic field created by the deflection electromagnet and in electron-beam acceleration, a given electron closed orbit is shifted between the collision and the non-collision regions, whereby the target and a circulating electron beam collide with each other, thereby generating electromagnetic waves.

2. The electromagnetic wave generator according to claim 1, wherein, in a single injection, an electron beam travels at least times from the non-collision region to the collision region.

3. The electromagnetic wave generator according to claim 1, wherein, for each injection, timing at which an electron closed orbit, decided at a time point when an injection ends, is shifted from the non-collision region to the collision region, is variably controlled.

4. The electromagnetic wave generator according to claim 1, wherein, during injection and acceleration of an electron beam, the deflection magnetic field is controlled have a to be constant strength.

5. The electromagnetic wave generator according to claim 1, wherein, during injection of an electron beam, the deflection magnetic field is controlled to have a strength that decreases with time.

6. The electromagnetic wave generator according to claim 1, wherein an electron beam is injected through a periphery of the electromagnetic wave generators, upon with acceleration of the electron beam, the closed orbit of the electron beam is radially reduced.

7. The electromagnetic wave generator according to claim 1, wherein the target includes of a wire.

8. The electromagnetic wave generator according to claim 7, wherein the target includes a material that is mounted on the wire and that has an effective atomic number larger than that of a material of the wire.

9. The electromagnetic wave generator according to claim 1, wherein the target includes a heavy metal material.