JP2001313435A - Free electron laser facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a free electron laser facility, capable of reducing photon cost by relatively decreasing an apparatus installing area of a free electron laser generator, improving the area efficiency of a laser beam output, and enabling a utilization of a large quantity of the laser beam. SOLUTION: The free electron laser facility comprises one group of common high-frequency power sources 21, 22, respectively, provided at a plurality of the free electron laser generators, to supply a high-frequency power to each high-frequency accelerator 2 of the plurality of the laser generators from the common high-frequency power sources.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free electron laser equipment provided with a plurality of free electron laser generators.

[0002]

2. Description of the Related Art A free-electron laser generator can generate a laser beam having a strong peak output, and can freely select a wavelength of a laser beam to be emitted from an ultraviolet region to a far-infrared region. In addition to basic experiments in science and chemistry, it is also being actively used in various fields such as medical, bio, and semiconductor fields. As a beam source of a free electron laser generator, a method of generating a high-frequency electric field in an acceleration cavity and accelerating an electron beam is most commonly used. The maximum output of the free electron laser is a value obtained by dividing the output of the electron beam by twice the number of periodic magnetic fields of the undulator. In order to obtain an oscillating gain, the number of periodic magnetic fields is required to be 30 or more, and usually about 60, so that the conversion efficiency from electron beam energy to laser light is only about several percent.

[0003] The output of a high-frequency power supply is determined by the performance of a high-frequency amplifier called a klystron. The size of the klystron and the high-voltage pulse power supply required for operating the klystron does not change to the left depending on the magnitude of the output of the high-frequency power supply.
m, length 7 m, and height 2.5 m. The size of this standard high-frequency power supply is approximately the same as the size of a standard free electron laser generator main body composed of an electromagnet, an acceleration tube, a vacuum chamber, a gantry, and the like. Therefore, even if the free electron laser generator is designed to be compact in response to the demand for downsizing of the apparatus, the size of the high-frequency power supply including the klystron and the high-voltage pulse power supply does not become smaller, so that the entire equipment cannot be downsized. For this reason, it is not easy to improve the area efficiency based on the ratio of the free electron laser output to the installation area of the apparatus.

Incidentally, Japanese Patent Application No. 9-3 filed by the applicant of the present invention.
As shown in FIG. X, the free electron laser generator already disclosed in Japanese Patent Publication No. 07196 discloses a single free electron laser generator in which a plurality of sets of undulators and resonators are installed in series. It is possible to get However, in such a device, in order to emit a laser beam having an equivalent output from a plurality of undulators, it is necessary to re-accelerate and decelerate to reproduce an electron beam, and to improve the area efficiency of the device itself. It is difficult.

[0005]

An object of the present invention is to improve the area efficiency of laser light output by relatively reducing the installation area of a free electron laser generator. Another object of the present invention is to provide a free electron laser facility that can use a large amount of laser light, reduce photon cost, and can simultaneously generate free electron lasers having different wavelengths.

[0006]

In order to solve the above-mentioned problems, a free electron laser apparatus according to the present invention comprises a common electron beam source, a high-frequency accelerator, and a plurality of free electron laser generators each including an undulator. Equipped with a high frequency power supply,
High frequency power is supplied from a common high frequency power supply to each high frequency accelerator of the plurality of free electron laser generators. Since the free electron laser equipment of the present invention shares one high-frequency power supply for a plurality of high-frequency accelerators,
The ratio of the installation area of the apparatus to the laser output of the entire equipment is significantly smaller than that of a conventional apparatus in which each free electron laser generator has a high-frequency power supply device, and the area efficiency of the equipment is improved.

In particular, by applying a linac or a high-frequency electron gun having an energy of 50 MeV or less to an electron beam source, a far-infrared laser facility that combines and uses a large number of laser beams in the infrared or far-infrared region. be able to. Klystron has an output of 10MW to 80MW
The electron beam energy required for the far-infrared free electron laser generator is about 2 MeV to 10 MeV, and the average current of the macro pulse is several hundred m.
The high-frequency output required for this is 10 MW or less, and the high-frequency output is 20 MW to 30 MW even with a free electron laser device in the infrared region with an electron beam energy of 20 MeV to 50 MeV and a macropulse average current of 100 mA or more. Accordingly, a plurality of free electron laser generators can be driven by one klystron, and the area efficiency and the total cost of the facility are improved. Further, a plurality of free electron lasers can be generated simultaneously.

[0008] A plurality of laser generators in the free electron laser facility may all generate free electron laser light of the same wavelength. In addition, at least one of the free electron laser generators may generate free electron laser light having a different wavelength from the other, and may simultaneously generate laser lights having different wavelengths. In addition, each free electron laser generator may be formed to be a unit device having the same dimensions and the same configuration, and the free electron laser generators may be juxtaposed or stacked to constitute a laser facility. The unitization reduces the manufacturing cost and maintenance cost, and the juxtaposition, particularly the vertical stacking, significantly improves the area efficiency of the equipment.

It is preferable that a circuit for superimposing the laser light on a transport path of the laser light emitted from the free electron laser generator is provided. In the laser equipment of the present invention, since laser beams of the same quality can be obtained from each laser generator, a high-power laser beam obtained by combining laser beams obtained from each laser generator can be obtained by superimposing laser beams. it can. Further, a circuit for shifting the laser beams in phase can be provided. Since the laser output is made continuous by shifting a plurality of laser beams emitted in a pulsed manner from each other, it can also be used for applications requiring a continuous light laser.

In order to solve the above-mentioned problem, a second free electron laser equipment of the present invention comprises two accelerating cavities, one common high-frequency power source, one undulator, and a pair of undulators. And two deflecting magnets are respectively provided between the resonator mirror and the undulator, and the first accelerating cavity is provided with a first high-frequency electric field generated by high-frequency power supplied from a common high-frequency power supply. The electron beam is accelerated and supplied to the first deflecting magnet. The first deflecting magnet guides the first electron beam from one end of the undulator to the axis of the undulator, and the second deflecting magnet travels on the axis of the undulator. The first electron beam is deflected off axis and dumped, while the second accelerating cavity accelerates the second electron beam with a high frequency electric field generated by a common high frequency power supply and supplies it to the second deflection magnet A second deflecting magnet guides the second electron beam onto the undulator axis from a side opposite to the first electron beam, and causes the first deflecting magnet to dump the second electron beam. Operates with light resonating between the first and second resonator mirrors while traveling through the undulator to generate a free electron laser.

According to the second free electron laser equipment of the present invention, one high-frequency power supply is commonly used for two accelerating cavities, and an undulator is shared. Free electron laser equipment with high area efficiency can be saved. Note that a first phase adjuster and a second phase adjuster are provided between the first accelerating cavity and the common high frequency power supply.
A second phase adjuster is provided between the accelerating cavity and the common high-frequency power supply to adjust the phase of the high-frequency electric field in each accelerating cavity so that the traveling of the electron beam is synchronized with the traveling of the bunch of light resonating in the undulator. It is preferable to adjust.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings.

[0013]

Embodiment 1 FIGS. 1 to 3 are configuration diagrams showing a free electron laser facility according to a first embodiment of the present invention. In the free electron laser equipment of this embodiment, a plurality of free electron laser generators are juxtaposed, and a high frequency power is supplied from one common high frequency power supply to a high frequency accelerator or a high frequency electron gun installed in each free electron laser generator. It is intended to be supplied.
In the free electron laser equipment shown in FIG. 1, the free electron laser generators each generate a free electron laser in the infrared region, and include an electron gun 1, a main accelerator 2, deflection magnets 3, 6,
The undulator 7, the deflecting magnet 8, the beam damper 11, and the resonator mirrors 4, 9 arranged with the undulator 7 interposed therebetween, and the mirror chambers 5, 10 for housing the resonator mirrors are configured as main elements.

The free electron laser generator accelerates an electron beam generated by an electron gun 1 by a main accelerator 2 under the action of a high-frequency electric field, and introduces it to an undulator 7 via deflection mirrors 3 and 6 via a resonator mirror 4. The synchrotron light is generated while meandering with the alternating magnetic field of the undulator 7. While the synchrotron light reciprocates between the resonator mirrors 4 and 9,
The light energy is sequentially increased by interfering with the electron beam, output from the resonator mirror 9, and transferred to the user room.

In the free electron laser equipment, a high frequency power supply 21 and a klystron 22 driven by it are provided.
A plurality of infrared free electron laser generators having the same configuration are juxtaposed. Klystron 22 to waveguide 26
Is distributed by a divider 23 provided for each free electron laser generator, and a required amount is supplied to the accelerator 2 via an attenuator 24. Since the waveguide path lengths from the klystron 22 to the respective free electron laser generators are different, the waveguide 26 is provided with a phase adjuster 25 for each free electron laser generator, and the laser generators arranged side by side are arranged side by side. The laser output of the device is matched.

Electron beam energy and undulator 7
A free electron laser beam having a wavelength determined by the magnetic field of the light from the
2 and is introduced into an optical path guided to the user room.
Laser light generated by another free electron laser generator enters the rear surface of the semi-transmissive mirror 12, is transmitted therethrough, is combined with the laser light, and is supplied to the user room. In addition, by using the phase adjuster 25 to adjust the pulse phase of the laser light generated by each free electron laser generator, a plurality of pulse lasers can be synthesized to increase the continuous time of the macro pulse, Further, the laser can be made continuous.

The output of the klystron 22 is distributed to the accelerator 2 of each free electron laser generator in increments of 20 MW to 30 MW. The accelerator 2 accelerates the electron beam supplied from the electron gun 1 to increase the energy from 20 MeV to 50 MeV,
It is supplied to the undulator 7 as an electron beam having a macropulse average current of 100 mA or more. An infrared free electron laser is emitted from the resonator mirror 9,
And is sent to the user room in combination with the laser light emitted from the other. The free electron laser equipment of this embodiment can generate a plurality of free electron lasers simultaneously and can drive a plurality of free electron laser generators with one klystron.

Incidentally, by adjusting all of the juxtaposed free electron laser generators so that the laser conditions are the same, it is possible to increase the intensity of the free electron laser light output to the user room by synthesizing them. it can. In addition, by adjusting the pulse phase, the time of the macro pulse can be lengthened, or the interval between the pulses can be reduced to provide a continuous output. It goes without saying that by operating the individual free electron laser generators under different conditions, it is possible to obtain free electron laser beams having different wavelengths. Further, since the size and cost of the high-frequency power supply device and the klystron are not proportional to the output, the area efficiency and the total cost of the facility are improved. Further, it is possible to reduce the cost ratio of the free electron laser light to the number of photons, that is, the photon cost.

The free electron laser equipment shown in FIG. 2 has a plurality of free electron laser generators that emit laser light in the far-infrared region juxtaposed. The free electron laser generator in this embodiment is different from the one shown in FIG. 1 only in that a high-frequency electron gun 16 is provided instead of the electron gun 1 and the accelerator 2 to generate a free electron laser in the far infrared region. There is no difference in composition and effect.

In the free-electron laser generator of this embodiment, a high-frequency electric field is generated by the high-frequency electron gun 16 to extract electrons, which are introduced into the undulator 7 by the deflecting magnets 3 and 6 to generate synchrotron light. The synchrotron light resonates between the resonator mirrors 4 and 9 while undergoing an interference action with the electron beam to become laser light, and is output from the resonator mirror 9. The free-electron laser light in the far-infrared region has a strong electromagnetic wave property, and can be transported to the user room by the waveguides 13 and 4. Further, it is possible to combine light outputs when guiding the light through a waveguide, or to deflect the phases of a plurality of lights. Therefore, each free electron laser device is provided with a synthesizer 15 corresponding to the output, and is combined with the far-infrared laser light emitted from the other laser generators to form a strong free electron laser light or a continuous laser light in the user room. To supply.

The output of the klystron 22 is distributed to the high-frequency electron gun 16 of each free electron laser generator by about 10 MW. The high-frequency electron gun 16 accelerates the thermoelectrons in a high-frequency electric field and supplies the undulator 7 as an electron beam having an energy of 2 MeV to 10 MeV and an average macropulse current of several hundred mA or more. A free-electron laser in the far-infrared region is emitted from the resonator mirror 9, combined with laser light emitted from the other by the combiner 15, and sent to the user room.

The free electron laser equipment according to the third embodiment of the present invention shown in FIG. 3 comprises a free electron laser generator for emitting laser light in the infrared region shown in FIG. 1 and a far electron laser device shown in FIG. A free electron laser generator that emits laser light is mixed, so that free electron laser lights in different wavelength regions are obtained at the same time. Other configurations are the same as those of the free electron laser equipment of FIG. 1 or FIG.
The free electron laser generator in this embodiment distributes high frequency power from the klystron 22 to the accelerator 2 in the infrared free electron laser generator and the high frequency electron gun 16 in the far infrared free electron laser generator. The laser light in the infrared region is gathered by the optical system including the semi-transmissive mirror 12 and supplied to the user room, and the laser light in the far infrared region is combined with other laser light by the combiner 15 and supplied to the user room. You.

In the free electron laser equipment of this embodiment, one or two or more laser lights in the infrared region and the far infrared region are simultaneously emitted by installing a free electron generator as long as it can fit in the capacity of the klystron 22. Supply to the user,
The user can perform various experiments utilizing characteristics based on the wavelength of the laser light, such as knowing how a substance changes by heating using far-infrared rays by infrared analysis.

[0024]

Embodiment 2 FIG. 4 is a block diagram showing a second embodiment of the present invention. In the free electron laser equipment of this embodiment, two electron beams are introduced into one undulator to output two types of free electron lasers or double the power. As shown in the figure, deflecting magnets 17 are provided at both ends of the undulator 7 for irradiating electron beams from two directions and deflecting them by the same angle.
The electron beam emitted from the high-frequency electron gun 16 on the left side in the figure is introduced into the undulator 7 by the action of the deflecting magnets 3 and 17 on the left side in the figure, and is discharged to the beam dump 11 by the right deflecting magnet 17 after passing through the undulator 7. Is done. Further, the electron beam emitted from the high-frequency electron gun 16 on the right side in the drawing passes through the deflecting magnets 3 and 17, passes through the undulator 7, and is then discharged to the beam dump 11 by the left deflecting magnet 17.

High frequency power from one klystron 22 is distributed to the two high frequency electron guns 16. If the energies of the electron beams provided by the two high-frequency electron guns 16 are equal, the free electron laser light generated by the undulator 7 has the same wavelength, and one of the resonator mirrors 9
The energy of the free electron laser extracted from the laser is doubled. Further, by shifting the phase of the high frequency, a free electron laser having a longer output pulse portion can be taken out. Further, when the energy given by the two high-frequency electron guns 16 is different, the properties of the free electron laser generated due to the respective electron beams are different, so that the user can obtain two types of free electron lasers simultaneously. it can.

[0026]

Embodiment 3 FIG. 5 is a block diagram showing a third embodiment of the present invention. In the free electron laser equipment of this embodiment, the area efficiency is further improved and the manufacturing cost is reduced by unitizing and using the free electron laser generator in a three-dimensional manner. A portion downstream of the high-frequency distributor for each free electron laser generator and upstream of the output laser combiner is incorporated into a stackable frame of the same shape to form a unit device having the same dimensions and the same configuration. A required number of unit devices are juxtaposed or stacked up and down, a waveguide from the klystron 22 is connected, and an output waveguide is connected to form a free electron laser facility.

By unitizing the free electron laser generator, manufacturing costs and maintenance costs are reduced, and by arranging it three-dimensionally, the area efficiency as equipment is significantly improved. In particular, in the free-electron laser generator in the far-infrared region, the photon cost can be reduced because the required high-frequency power per device is small, but since the device is small, the unit is small as in this embodiment. By arranging and using them three-dimensionally, it is possible to further improve the area efficiency and reduce the manufacturing cost.

[0028]

As described above, the free electron laser equipment of the present invention utilizes the fact that the cost and the size of the klystron have a small dependence on the high frequency output, and a high frequency drive type free electron laser generator is used. By being able to drive these at the same time with multiple facilities,
The installation area of the whole equipment was reduced, the area efficiency was improved, and the photon cost was able to be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a free electron laser facility according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the free electron laser equipment of the first embodiment.

FIG. 3 is a configuration diagram showing a third embodiment of the free electron laser equipment of the first embodiment.

FIG. 4 is a configuration diagram illustrating a free electron laser facility according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating a free electron laser facility according to a third embodiment of the present invention.

FIG. 6 is a plan view showing an example of a conventional free electron laser facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron gun 2 High frequency accelerator 3,6,8 Deflection magnet 4,9 Resonator mirror 5,10 Mirror chamber 7 Undulator 11 Beam damper 12 Semi-transmissive mirror 13,14 Laser waveguide 15 Synthesizer 16 High frequency electron gun 17 Deflection magnet DESCRIPTION OF SYMBOLS 21 High frequency power supply 22 Klystron 23 Divider 24 Attenuator 25 Phase adjuster 26 Waveguide 30 Free electron laser generation unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G085 AA03 AA18 BA01 BA14 BA17 BA19 BB17 BB20 CA02 CA18 DB02 DB08 DB10 EA06 5F072 AC10 HH03 JJ02 JJ04 JJ08 KK06 PP05 RR10 SS06 YY01 YY20

Claims (9)

[Claims] 1. A common high-frequency power source is provided for a plurality of free electron laser generators each including an electron beam source, a high-frequency accelerator, and an undulator, and the plurality of free electron laser generators are supplied from the common high-frequency power source. Free-electron laser equipment characterized by supplying high-frequency power to each high-frequency accelerator. 2. The free electron laser equipment according to claim 1, wherein said plurality of free electron laser generators all generate free electron laser light having the same wavelength. 3. The free electron laser equipment according to claim 1, wherein at least one of said plurality of free electron laser generators generates free electron laser light having a wavelength different from the others. 4. The free electron laser generator according to claim 1, wherein the plurality of free electron laser generators have the same dimensions and the same configuration, and the free electron laser generators are arranged side by side or stacked. The free electron laser equipment described in Crab. 5. An electron beam source having an energy of 50 Me.
The free electron laser equipment according to any one of claims 1 to 4, wherein the equipment is a linac or a high-frequency electron gun of V or less. 6. The free electron laser equipment according to claim 1, wherein a wavelength of the laser light generated by said plurality of free electron laser generators is in a far infrared region. 7. The method according to claim 1, further comprising a circuit for superimposing the laser light or a circuit for shifting the laser light in a transport path of the laser light emitted from the plurality of free electron laser generators. Free electron laser equipment according to any of the above. 8. A first and second two accelerating cavities, one common high-frequency power source, one undulator, and first and second two pairs of the undulator sandwiched therebetween. A resonator mirror, and first and second deflecting magnet groups respectively between the first and second resonator mirrors and the undulator;
The first accelerating cavity accelerates a first electron beam by a high-frequency electric field generated by high-frequency power supplied from the common high-frequency power supply, and supplies the first electron beam to the first deflection magnet group.
A deflecting magnet group directs the first electron beam from one end of the undulator onto an undulator axis, and the second deflecting magnet group travels on the undulator axis.
The second accelerating cavity is accelerated by the high-frequency electric field generated by the high-frequency power supplied from the common high-frequency power supply, and the second electron beam is deflected off the axis to be dumped. Supplying, the second group of deflection magnets guides the second electron beam on the axis of the undulator from the other end of the undulator, and the first group of deflection magnets travels on the axis of the undulator. Deviates from the axis to cause the free electron laser to interact with light resonating between the first and second resonator mirrors while the first and second electron beams travel through the undulator. Producing free electron laser equipment. 9. An undulator for driving a bunch of light resonating in the undulator, comprising first and second phase adjusters between the first and second acceleration cavities and the common high-frequency power supply, respectively. 9. The free electron laser equipment according to claim 8, wherein the phases of the high-frequency electric fields in the first and second accelerating cavities are adjusted so that the traveling of the beam is synchronized.