JPH03280586A - Free electron laser device - Google Patents

Abstract

PURPOSE:To realize a strong laser oscillation by bringing the direction of an electron beam into coincidence with that of an oscillation radiation light bent by a reflecting mirror for forming a polygonal optical path at a wiggler's position by a deflecting magnet, vibrating the beam by the wiggler to circulate it while amplifying an oscillation radiation light, thereby performing a laser oscillation. CONSTITUTION:An electron beam 6 of a high speed is implanted from an electron beam incident unit 5 to a circulating orbit of the beam 6 to be formed by a deflecting magnet 4. The beam 6 is brought into coincidence with the direction of an oscillation radiation light 2 bent by a reflecting mirror 1 at the position of a wiggler 3 by the magnet 4. The wiggler 3 vibrates the beam 6 in a wave state. If the vibration period is integer number of times of the wavelength of the light 2 and the speed of the electron is suitable, it is resonated, part of the energy of the electrons is transferred to the light 2, and the light 2 is amplified. In this case, since a polygonal resonator is formed of 8 reflecting mirrors 1, the light 2 becomes a laser oscillation light, and output as an output radiation light 9 from a hole 8 or the like formed partly at an arbitrary mirror 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a free electron laser device capable of providing a powerful light source in the X-ray region.

2. Description of the Related Art Recent free electron lasers have gradually become capable of oscillating at shorter wavelengths, and oscillation at a wavelength of 100 OA of soft X-rays has also been reported. Such free electron lasers can be used as powerful light sources in the X-ray region (Kuniyoshi Mima,
"Free Electron Laser" Laser Research, Volume 15, No. 6 (
(1986), see pages 52 to 57). Hereinafter, a conventional free electron laser device will be described with reference to the drawings.

FIG. 3 is a configuration diagram showing a conventional free electron laser device. In FIG. 3, 31 and 32 are arranged to face each other, and the reflecting mirrors 1 and 34 forming the optical path of each oscillated radiation beam are the reflecting mirrors 3 and 3.
The wiggler is placed between 1 and 32, and applies a horizontal periodic electromagnetic field to the electron beam I, which will be described later, to cause the electron beam I to vibrate in a wave-like manner. 35 is an electron beam injector for injecting the electron beam I into the optical path formed by the reflecting mirrors 31 and 32; 37 is placed between the reflector 31 and the wiggler, and is used to inject the electron beam I into the optical path formed by the electron beam injector 31 and 32; A deflecting magnet that deflects parallel to the optical path is placed between the wiggler beam and the reflector support and guides the electron beam I that has passed through the wiggler beam out of the optical path.

The operation of the above configuration will be described below.

A high-speed electron beam I is shot into the deflection magnet 37 from the electron beam injection device. The electron beam I is deflected by a deflection magnet 37 parallel to the optical path of the oscillated synchrotron radiation, and enters the wiggler A. In Wiggler-san, the electron beam I is made to vibrate in a wave-like manner. If this oscillation period is an integral multiple of the wavelength of the oscillating synchrotron radiation and the speed of the electrons is appropriate, it resonates, and part of the electron energy is transferred to the oscillating synchrotron radiation.
The oscillating synchrotron radiation is amplified. At this time, the two reflecting mirrors 3
1.32 constitutes a resonator, the oscillated radiated light or laser oscillated light is extracted as output radiated light 40 from a hole 39 formed in a part of the reflecting mirror 32 or the like.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the reflecting mirror 31.
32 facing each other to form a resonator, but in the X-ray region, the reflectance is high for normal incidence, there is no highly durable reflecting mirror, and it is difficult to withstand strong synchrotron radiation. This is a major obstacle to realizing powerful laser oscillation with short wavelengths in the X-ray region.

The present invention solves the problems of the prior art as described above, and aims to increase the reflectance of a reflecting mirror in the X-ray region, improve durability, and realize powerful laser oscillation. It is an object of the present invention to provide a free electron laser device in which the electron beam is repeatedly used for laser oscillation and the efficiency of laser oscillation can be improved.

Means for Solving the Problems In order to achieve the above object, the technical solution of the present invention includes a plurality of reflecting mirrors arranged to form a polygonal optical path with an incident angle of 60° or more. , a plurality of wigglers placed between the reflecting mirrors to vibrate the electron beam in a wave-like manner, and oscillation radiation whose direction of the electron beam is bent by the reflecting mirrors at the position of the wigglers, which is placed between the wigglers. a deflection magnet that aligns the direction of the light and forms an orbit of the electron beam; an electron beam injector that injects the electron beam into the orbit of the electron beam; It is equipped with an electron beam accelerator that accelerates the

At least the surface of the reflecting mirror is 5iC1Pts.
It is preferable to use a material selected from AuXCuXNi and having AuXCuXNi as its main component.

Therefore, according to the present invention, the direction of the electron beam incident from the electron beam injection device is made to coincide with the direction of the oscillated radiation bent by the reflecting mirror forming a polygonal optical path at the wiggler position by means of a deflecting magnet, and the wiggler The electron beam can be vibrated in a wave-like manner and the oscillated synchrotron radiation can be amplified while circulating to generate a laser oscillation. It is possible to increase the reflectance in the line region and also improve the durability. Furthermore, the energy of the electron beam can be constantly replenished by accelerating the electron beam by an electron accelerator placed in the orbit formed by the deflecting magnet.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing a free electron laser device in one embodiment of the present invention.

In FIG. 1, l is a reflecting mirror, and the oscillating radiation 2 has a polygonal shape (regular octagonal in the illustrated example) with an incident angle of 60° or more.
A plurality of them (eight in the illustrated example) are arranged so as to form an optical path of . Numeral 3 denotes wigglers, which are arranged in plural numbers (six in the illustrated example) between the reflecting mirrors 10, and apply a horizontal periodic electromagnetic field to the electron beam 6, which will be described later, to vibrate the electron beam 6 in a wave-like manner. Reference numeral 4 denotes a deflection magnet, which is arranged in plural pieces (eight in the illustrated example) between the wigglers 3, and deflects the direction of the electron beam 6 by the reflecting mirror 1 at the position of the wiggler 3.
The direction of the electron beam is made to coincide with the direction of the electron beam to form a 60-turn orbit of the electron beam. By arranging the deflection magnet 4 in a position overlapping the reflecting mirror 1, the direction of the electrons 116 can be easily made to coincide with the direction of the oscillation radiation 2, but it is not necessarily necessary to arrange the two in an overlapping position. 5 is an electron beam incidence device;
A high-speed electron beam 6 is shot into the orbit of the electron beam 6 formed by the deflecting magnet 4. 7 is an electron beam accelerator, deflection magnet 4
A plurality of (in the illustrated example, two) orbits of the electron beam 6 formed by
) are arranged to accelerate the electron beam 6.

The operation of the above configuration will be described below.

A high-speed electron beam 6 is ejected from an electron beam injection device 5 into an electron beam 60 orbit formed by a deflection magnet 4. The electron beam 6 is made to coincide with the direction of the oscillated radiation 2 bent by the reflector 1 at the position of the swiggler 3 by the deflection magnet 4. The wiggler 3 vibrates the electron beam 6 in a wave-like manner. When this oscillation period is an integral multiple of the wavelength of the oscillated radiation 2 and the speed of the electrons is appropriate, resonance occurs, a part of the energy of the electrons is transferred to the oscillated radiation 2, and the oscillated radiation 2 is amplified. At this time, since the eight reflecting mirrors 1 constitute a polygonal resonator, the oscillated radiation 2 is not a laser oscillation light, and the hole 8 formed in a part of the reflecting mirror 1, etc. The output radiation light 9 is extracted from the output beam 9.

The electron beam 6Fi is repeatedly used for orbital movement, which helps in laser oscillation, and since the energy of the electron beam 6 is constantly replenished by the electron beam accelerator 7, safe laser oscillation can be continued, and the laser oscillation can be continued safely. Oscillation efficiency can be improved.

In addition, since the reflecting mirror 1 is arranged to have a large incident angle of 60° or more, when the incident angle is set to such a large angle, X-rays can be It is possible to maintain a high reflectance even in the wavelength range, and because it does not require the use of multilayer films like conventional X-ray reflectors, it is highly durable and can be used even when oscillating high-intensity X-rays. It becomes possible to prevent the reflection mirror l from being destroyed. below,
A specific example will be explained.

Figures 2 (a) and (b) show SiC and Pt on the surface of the reflecting mirror l.
FIG. 4 is a diagram showing the relationship between the reflectance and the wavelength of the X-ray region and the angle of incidence (the parameter is the angle of incidence) when using each of them. As is clear from FIGS. 2(a) and (b),
When SiC or PT is used on the surface of the reflecting mirror 10, it has a high reflectance at an incident angle of 60° or more at a wavelength of 100 A to 400 A in the X-ray region. In this X-ray wavelength range, other materials that exhibit high reflectance at an incident angle of 60° or more include 7ku, Cu, and Ni. By using it on the surface of the mirror, high reflectance and high durability can be achieved at the same time, and it is suitable for use as a material for the reflecting mirror 1 of the present invention.

In addition, although the above embodiment shows the case where the reflecting mirror 1 is arranged so as to form a regular octagonal optical path, a polygon other than a regular octagon may be used if the reflecting mirror 1 is arranged so that the incident angle is 60° or more. But it's okay.

Effects of the Invention As described above, according to the present invention, the direction of the electron beam incident from the electron beam injection device is bent by the deflecting magnet and the reflecting mirror that forms a polygonal optical path at the position of the swiggler. The electron beam is vibrated in a wave-like manner by a twiggler, and the oscillated radiation is amplified while circulating to generate a laser oscillation. Because of this arrangement, reflectance can be increased in the X-ray region, and durability can be improved. Therefore, strong laser oscillation can be achieved in the X-ray region. Furthermore, the energy of the electron beam can be constantly replenished by accelerating the electron beam by an electron accelerator placed in the orbit formed by the deflecting magnet.

Therefore, laser oscillation efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a free electron laser device according to an embodiment of the present invention, and FIGS. 2(a) and (b) show X-rays when SiC and PL are used for the surface of the reflecting mirror of the above embodiment. Diagram showing the relationship between the reflectance and the wavelength of the region and the angle of incidence, 3rd
The figure is a configuration diagram showing a conventional free electron laser device. DESCRIPTION OF SYMBOLS 1... Reflection mirror, 2... Oscillation synchrotron radiation, 3... Wiggler 4... Polarizing magnet, 5... Electron beam incidence device, 6...
...Electron beam, 7...Electron beam accelerator, 9...Output synchrotron radiation.

Claims (2)

[Claims] (1) A plurality of reflecting mirrors arranged to form a polygonal optical path with an incident angle of 60° or more, and a plurality of wigglers arranged between the reflecting mirrors to vibrate the electron beam in a wave-like manner. and a deflecting magnet disposed between the wiggler, which aligns the direction of the electron beam with the direction of the oscillated radiation bent by the reflecting mirror at the position of the wiggler, and forms an orbit of the electron beam; A free electron laser device comprising: an electron beam injection device that injects an electron beam into an orbit of the electron beam; and an electron beam accelerator that is arranged in the orbit of the electron beam and accelerates the electron beam. (2) At least the surface of the reflecting mirror is SiC, Pt, Au,
2. The free electron laser device according to claim 1, wherein the free electron laser device is made of a material selected from CuNi and having CuNi as its main component.