JPH06180396A - Synchrotron radiation mask unit for undulator - Google Patents

Abstract

(57) [Abstract] [Purpose] S of high energy state from undulator
An object of the present invention is to provide a radiation light mask device for an undulator that can reduce the heat load on the optical element even when the OR light is emitted. [Structure] A pair of horizontal mask plates 14a and 14b are arranged so as to advance and retreat in order to block a part of the emitted light S in the horizontal direction. A pair of vertical mask plates 15a and 15b are arranged so as to advance and retreat in order to block a part of the emitted light S in the vertical direction. Also, a pair of horizontal mask plates 1
Reference numerals 4a and 14b denote a predetermined angle θ1 with respect to a vertical plane where the irradiation surface 17 that blocks the emitted light S passes through the optical axis P of the emitted light S.
It is arranged at an inclination. In addition, a pair of vertical mask plates 15
The a and 15b are arranged so that the irradiation surface 18 that blocks the emitted light S is inclined at a predetermined angle θ2 with respect to the horizontal plane that passes through the optical axis P of the emitted light S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation light mask device for an undulator arranged downstream of an undulator for extracting radiation light (SOR light) by deflecting an electron beam with a periodic magnetic field.

[0002]

2. Description of the Related Art FIG. 5 shows a basic structure of an undulator 1. Reference numeral 2 in the figure is the trajectory of the electron beam, and the electron beam having a velocity close to the speed of light passes along the trajectory 2. Moreover, the rod-shaped permanent magnets 3 and 3 which are paired up and down are provided above and below the track 2.
Are opposed to each other. The permanent magnets 3 and 3 of the pair are
A large number of them are arranged along the longitudinal direction of the track 2, and their polarities change periodically.

Therefore, a magnetic flux in the vertical direction is generated between each pair of permanent magnets 3, 3 and the direction of the magnetic flux is alternately inverted, whereby an electron beam passing through the orbit 2 is formed. On the other hand, a periodic magnetic field is applied, and the electron beam meanders in the direction perpendicular to the magnetic flux, that is, in the horizontal direction as shown in the figure, and the SOR light S having a strong wavelength is radiated in the tangential direction during the meandering. is there.

S taken out by the undulator 1
As shown in FIG. 6, the OR light S includes an on-axis light S1 that is substantially parallel to the optical axis P, and an interference light (primary, secondary, and high-order interference light) S2 having a predetermined spread angle σ. As the main light component,
It is emitted to an optical element 4 composed of a mirror, a double-crystal spectroscope, and a filter arranged on the downstream side, and after being made a specific wavelength by the optical element 4, it is used for a free electron laser device 5 or the like. It has become. Here, of the SOR light S emitted to the optical element 4, only the axial light S1 has a specific wavelength and is used for the free electron laser device 5.

[0005]

By the way, in recent years, high energy SOR light S may be extracted from the undulator 1 and incident on the optical element 16.
However, when the high energy SOR light S is emitted from the undulator 1, in the conventional technique, an extremely large heat load is applied to the mirror, the double crystal spectroscope, and the like that form the optical element 4, and the heat There was a risk that it would be destroyed.

In view of the above circumstances, the present invention provides a radiant light mask device for an undulator capable of reducing the heat load on the optical element even when the high energy SOR light S is emitted from the undulator. The purpose is to

[0007]

According to a first aspect of the present invention, there is provided an undulator radiation synchronism mask device for an undulator, wherein an undulator is taken out by deflecting an electron beam with a periodic magnetic field and an optic positioned downstream thereof. A radiant light mask device for an undulator that is placed between the element and that blocks part of the radiant light emitted from the undulator, and can freely move in and out to block part of the radiant light in the horizontal direction. A pair of horizontal mask plates arranged in a vertical direction and a pair of vertical mask plates arranged so as to be capable of advancing and retracting in order to block a part of the emitted light in the vertical direction. is there.

According to a second aspect of the present invention, there is provided an undulator synchrotron radiation mask apparatus according to the first aspect of the invention, wherein the pair of horizontal mask plates has an irradiation surface that blocks the radiant light passing through the optical axis of the radiant light. The device is characterized in that it is arranged at a predetermined angle with respect to the vertical plane.

Further, the radiant light mask device for an undulator according to a third aspect is the device according to the first or second aspect, in which the pair of vertical mask plates has an irradiation surface for blocking the radiated light, which has an optical axis of the radiated light. The device is characterized in that it is arranged at a predetermined angle with respect to a horizontal plane passing therethrough.

[0010]

The radiant light mask device for an undulator according to claim 1 of the present invention is disposed on the downstream side of the undulator so that the irradiation surfaces of a pair of horizontal mask plates that enter toward the trajectory of the radiated light. Since a part of the emitted light (first, second and higher order interference light) is blocked by the irradiation surface of the pair of vertical mask plates, even if high energy emitted light is emitted from the undulator, the optical element Only the required radiant light (axial light) is emitted, and the thermal load on the optical element is reduced.

Further, in the radiant light mask device for an undulator according to a second aspect, the irradiation surfaces of the pair of horizontal mask plates are:
Since it is arranged at a predetermined angle with respect to the vertical plane that passes through the optical axis of the synchrotron radiation, the irradiation area of the synchrotron radiation on the irradiation surface is expanded, and part of the high-energy radiation is blocked. However, the horizontal mask plate is kept at a low temperature.

Further, according to the radiant light mask device for an undulator described in claim 3, claim 1 or claim 2 is provided.
Irradiation surface of the pair of vertical mask plate described, since the inclined surface is arranged at a predetermined angle with respect to the horizontal plane passing through the optical axis of the emitted light, the irradiation area of the emitted light to the irradiation surface is enlarged,
Even if a part of the high-energy radiant light is blocked, the vertical mask plate maintains a low temperature state.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the undulation radiation mask device of the present invention will be described below with reference to FIGS.

1 to 3 show a chamber 11 in which a mask device 10 is provided. FIG. 1 is a sectional view in plan view, FIG. 2 is a sectional view in front view, and FIG.
Shows a side view. In the figure, reference numeral 12 is a take-out window for the SOR light S, and the SOR light S that enters the chamber 11 through the take-out window 12 about the optical axis P is the exit window 1.
The light is emitted from 3 toward the optical element 4.

The mask device 10 comprises a pair of horizontal mask plates 14a and 14b arranged horizontally on the upstream side 11a of the chamber 11 and a pair of vertical masks arranged vertically on the downstream side 11b. Plate 15a,
15b and each mask plate 14a, 14b, 15a, 15b
And a drive unit 16 for moving the inside of the chamber 11 back and forth.

The horizontal mask plates 14a and 14b are made of copper (C
u) or tungsten (W) as a material,
In addition to being formed into the external shape as shown in
The surface 17 irradiated with the R light S (hereinafter referred to as an irradiation surface) is
It is formed to have a smooth surface. The horizontal mask plates 14a and 14b in the chamber 11 are arranged so that the irradiation surface 17 is inclined at a predetermined angle θ1 with respect to the vertical plane passing through the optical axis P (see FIG. 1). .

On the other hand, as shown in FIG. 2, the vertical mask plates 15a and 15b are also made of a material similar to that of the horizontal mask plates 14a and 14b and have substantially the same shape, and a surface 18 (hereinafter, referred to as "sOR light") is irradiated. The irradiation surface) is also formed to be a smooth surface. The vertical mask plates 15a and 15b in the chamber 11 are arranged such that the irradiation surface 18 is inclined at a predetermined angle θ2 with respect to the horizontal plane passing through the optical axis P (see FIG. 2).

Next, the function and effect obtained by disposing the mask device 10 having the above-mentioned structure on the downstream side of the undulator 12 will be described. When the SOR light S extracted by the undulator 12 passes through the extraction window 12 and enters the chamber 11, the driving unit 16 causes S
Horizontal mask plates 14a, 14b toward the orbit P of the OR light S
4, the irradiation surfaces 17, 17 of the horizontal mask plates 14a, 14b block the horizontal interference light S2 of the SOR light S, as shown in FIG. In addition, the vertical mask plates 15a, 1a, 1
The vertical mask plates 15a, 15a
The irradiation surfaces 18 and 18 of b block the interference light S2 in the vertical direction of the SOR light S. As a result, of the SOR light S that has passed through the mask device 10, only the on-axis light S1 used in the free electron laser device 17 or the like is emitted to the optical element 16.

Therefore, of the SOR light S emitted from the undulator 12, the unused SOR light S (interference light S2) that is not used is blocked by the mask device 10, and the optical element 16 is blocked by the free electron laser device 17 or the like. S used
Since only the OR light S (axial light S1) is emitted, even if the high energy SOR light S is emitted from the undulator 12, the thermal load on the optical element 16 is reduced.

Further, since the irradiation surfaces 17 of the horizontal mask plates 14a and 14b are arranged at an angle of θ1 with respect to the vertical plane passing through the optical axis P, the high energy state S is obtained.
Even if the OR light S is irradiated, the irradiation area on the irradiation surface 14a is expanded, so that the horizontal mask plates 14a and 14b do not generate heat locally and the low temperature state is maintained. Furthermore, since the vertical mask plates 15a and 15b are inclined so that the irradiation surface 18 forms a predetermined angle θ2 with respect to the horizontal plane passing through the optical axis P, even if the high energy SOR light S is irradiated. The irradiation area on the irradiation surface 18 is expanded, so that the vertical mask plates 15a and 15b do not generate heat locally and the low temperature state is maintained.

As can be easily understood from the above description, the mask device 10 of this embodiment has the undulator 1.
The irradiation surfaces 17 and 17 of the horizontal mask plates 14a and 14b and the irradiation surfaces 1 of the vertical mask plates 15a and 15b, which are arranged on the downstream side of the SOR light S, are introduced toward the orbit of the SOR light S.
Since the extra SOR light S (interference light S2) is blocked by 8 and 18, high energy SO from the undulator 12
Even if the R light S is emitted, an extremely large heat load is not applied to the optical element 16 that sends the SOR light of a specific wavelength to the free electron laser device 17 or the like.

Moreover, even when the high energy SOR light S is irradiated from the undulator 12, the irradiation surfaces 17, 17 of the pair of horizontal mask plates 14a, 14b with respect to the horizontal plane passing the optical axis P of the SOR light S. Since the irradiation surfaces 18, 18 of the pair of vertical mask plates 15a, 15b are inclined at a predetermined angle θ1 and are inclined at a predetermined angle θ2 with respect to the vertical plane passing through the optical axis P of the SOR light S, The irradiation area of the SOR light S on the irradiation surfaces 17 and 18 is enlarged so that the horizontal mask plates 14a and 14b and the vertical mask plates 15a and 15 are formed.
The low temperature state of b can be maintained.

[0023]

As described above, according to the first aspect of the present invention.
By arranging the undulator radiation light mask device described above on the downstream side of the undulator, only the radiation light required by the optical element is emitted toward the optical element,
Since excess radiation is blocked, even if radiation of high energy is emitted from the undulator, it is possible to reduce the heat load on the optical element.

Further, in the synchrotron radiation mask apparatus for an undulator according to claim 2, the irradiation surfaces of the pair of horizontal mask plates are:
Since it is arranged at a predetermined angle with respect to the vertical plane that passes through the optical axis of the radiated light, the irradiation area of the radiated light on the irradiation surface is expanded, and even if a portion of the high-energy radiated light is blocked. The low temperature state of the horizontal mask plate can be maintained.

Further, in the radiant light mask device for an undulator according to a third aspect of the present invention, the irradiation surfaces of the pair of vertical mask plates are arranged so as to be inclined at a predetermined angle with respect to the horizontal plane passing through the optical axis of the radiated light. Therefore, the irradiation area of the radiated light on the irradiation surface is enlarged, and the low temperature state of the vertical mask plate can be maintained even if a part of the radiated light of high energy is blocked.

Therefore, according to the present invention, even if high energy radiation is emitted from the undulator, the heat load on the optical element can be reduced and the high temperature heat of the device itself can be prevented. A mask device can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing a chamber in which a synchrotron radiation mask apparatus for an undulator of the present invention is arranged.

FIG. 2 is a front cross-sectional view showing a chamber.

FIG. 3 is a side view showing a chamber.

FIG. 4 is a schematic view showing a state in which a radiation light mask device arranged between an undulator and an optical element blocks a part of radiation light.

FIG. 5 is a schematic diagram showing the structure of an undulator.

FIG. 6 is a schematic view showing a conventional undulator and an optical element arranged on the downstream side thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 undulator 4 optical element 10 mask device 11 chambers 14a, 14b horizontal mask plates 15a, 15b vertical mask plate 16 drive unit 17 irradiation surface of horizontal mask plate 18 irradiation surface of vertical mask plate P optical axis of emitted light S SOR light ( Synchrotron radiation) θ1 Horizontal mask plate tilt angle θ2 Vertical mask plate tilt angle

Claims (3)

[Claims] 1. A part of radiant light emitted from the undulator, which is disposed between an undulator from which radiant light is extracted by deflecting an electron beam with a periodic magnetic field and an optical element located downstream thereof. This is a synchrotron radiation mask device for undulators that blocks a part of the synchrotron radiation in the horizontal direction. A synchrotron radiation mask device for an undulator, comprising: a pair of vertical mask plates arranged so as to be capable of advancing and retreating in order to shut off. 2. The radiant light mask device for an undulator according to claim 1, wherein the pair of horizontal mask plates have an irradiation surface that intercepts the radiated light at a predetermined angle with respect to a vertical plane that passes through the optical axis of the radiated light. A synchrotron radiation mask device for undulators, which is arranged at an angle. 3. The radiant light mask device for an undulator according to claim 1 or 2, wherein the pair of vertical mask plates has a predetermined irradiation surface for blocking the radiated light with respect to a horizontal plane passing through the optical axis of the radiated light. A synchrotron radiation mask device for an undulator, which is arranged at an angle.