JPH065399A - Absorber in particle accelerator - Google Patents

Abstract

(57) [Summary] [Structure] The cooling water pipe 2 made of a material capable of absorbing the radiant light S is inserted into the storage ring 10 and is arranged at a position where the radiant light is to be shielded and absorbed. The water pipe is irradiated with radiant light. Then, the radiant light applied to the cooling water pipe is blocked and absorbed by the cooling water pipe itself. Further, the cooling water pipe is cooled by the cooling water passing through it. [Effect] Although the structure is extremely simple, a reliable shielding and absorbing effect can be obtained by the cooling water pipe. Further, the cooling water effectively prevents overheating of the cooling water pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorber provided in a storage ring of a particle accelerator such as a synchrotron for shielding and absorbing emitted light.

[0002]

2. Description of the Related Art As is well known, in a particle accelerator such as a synchrotron, synchrotron radiation light (SOR light) is emitted from a deflecting portion of a charged particle beam circulating in a storage ring. Extraction of light through a beam line and its effective use in various fields such as manufacturing of VLSI circuits, diagnosis in the medical field, molecular analysis, and structural analysis have been studied.

By the way, if the SOR light emitted from the charged particle beam circulating in the storage ring is accidentally applied to the inner wall surface of the storage ring, the temperature of that portion becomes high, and degassing occurs from there. As a result, there arise problems that the degree of vacuum in the storage ring is lowered, and the circulating charged particle beam collides with gas molecules to shorten its life. Therefore, in order to prevent the inner wall surface from being irradiated with the SOR light, an absorber for shielding and absorbing the SOR light has been conventionally attached to a key portion of the storage ring.

Of course, such an absorber can absorb SOR light efficiently, and S
Since it becomes high temperature itself by absorbing the OR light, heat resistance is also required. Therefore, the conventional general absorber is formed into a block shape by a copper material or a clad material of plural kinds of metal materials. The thing is general, and if necessary, cooling water is forced to cool it by passing it inside.

[0005]

However, in the block-shaped absorber as described above, a sufficient cooling effect is not always obtained even if cooling water is passed through the inside, and the absorber itself becomes overheated. Therefore, it has been demanded to develop an absorber excellent in cooling efficiency.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a storage ring in a particle accelerator in order to prevent radiated light emitted from a charged particle beam circulating in the storage ring from irradiating the inner wall surface of the storage ring. Is a absorber installed at a predetermined position for shielding and absorbing radiant light, and a cooling water pipe through which cooling water is passed is formed of a material capable of absorbing radiant light, and the cooling water pipe is placed in a storage ring. By inserting it and arranging it at a position where it should shield and absorb radiant light, the cooling water pipe is irradiated with radiant light,
The radiant light applied to the cooling water pipe is shielded and absorbed by the cooling water pipe itself, and the cooling water pipe is cooled by the cooling water passing through the inside. In this case, it is preferable to form cooling fins on the inner surface of the cooling water pipe.

[0007]

In the absorber of the present invention, the cooling water pipe is arranged at a position where the radiant light should be shielded and absorbed, and the radiant light is applied to the cooling water pipe. Since the cooling water pipe is made of a material capable of absorbing radiant light, the radiant light applied to the cooling water pipe is shielded and absorbed by the cooling water pipe itself. Then, when the cooling water pipe absorbs the radiated light, its temperature rises, but by passing the cooling water through the cooling water pipe, the cooling water pipe is directly cooled to prevent its overheating.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view (a cross-sectional view of a main part) showing a part of a storage ring 10 provided with an absorber 1 of this embodiment. In the storage ring 10 of this embodiment, a beam chamber 11 in which the charged particle beam B orbits and a getter pump chamber 12 in which a getter pump (not shown) is arranged communicate with each other, as shown in the cross-sectional shape of FIG. The part 13 is integrally formed. Reference numeral 14 is an exhaust port for making the entire inside of the storage ring 10 into an ultrahigh vacuum by exhausting from the getter pump chamber 12.

The charged particle beam B circulating in the beam chamber 11 of the storage ring 10 is deflected and emits the SOR light S in the tangential direction thereof, and the SOR light S passes through the communicating portion 13 and getster pump. Although being emitted to the chamber 12, the absorber 1 of the present embodiment is arranged at a position where the SOR light S is irradiated in order to prevent such SOR light S from reaching the inner wall surface of the storage ring 10. There is.

The absorber 1 is composed of a cooling water pipe 2 formed by bending it into a substantially U shape as shown in FIG. The cooling water pipe 2 is made of copper or aluminum alloy, for example, S
The cooling fin 3 is formed of a pipe material made of a material capable of absorbing the OR light S, and has a large number of cooling fins 3 on its inner surface as shown in FIG.
Are formed in a radial pattern. The tip of the cooling water pipe 2 is inserted into the storage ring 10 from the mounting port 15 provided on the outer peripheral side of the storage ring 10, and the cooling water pipe 2 is attached to the mounting port 15 by the flange 4 so that a vacuum can be maintained. The cooling water is circulated and supplied from a cooling water supply device (not shown).

In the absorber 1 having the above structure, the SOR light S
Since the cooling water pipe 2 is arranged at a position to shield and absorb the SOR light S, the cooling water pipe 2 is irradiated with the SOR light S. However, the cooling water pipe 2 is formed of a material capable of absorbing the SOR light S. Therefore, the SOR light S is shielded and absorbed by the cooling water pipe 2 itself, and is prevented from reaching the inner wall surface of the storage ring 10. Further, when the cooling water pipe 2 absorbs the SOR light S, its temperature rises, but the cooling water passed through the cooling water pipe 2 prevents the cooling water pipe 2 from overheating. In particular, since the cooling fins 3 are formed on the inner surface of the cooling water pipe 2, a sufficient heat transfer area is secured and excellent cooling efficiency is obtained. Of course, the amount of cooling water supplied to the cooling water pipe 2 and its water temperature may be appropriately set so that a sufficient cooling effect can be obtained.

The material of the cooling water pipe 2 is appropriately selected in consideration of the energy (wavelength) of the SOR light S to be absorbed, and when the SOR light S has high energy (wavelength is relatively short). Although it is preferable to use copper, when the energy is low (wavelength is long), a more inexpensive aluminum alloy can be used to obtain a sufficient shielding / absorption effect. When using an aluminum alloy, the cooling fin 3 as shown in FIG.
The cooling water pipe 2 having the can be easily formed by extrusion molding.

Further, the shape and size of the cooling water pipe 2 in the absorber 1 of the present invention, the wall thickness, the presence or absence of the cooling fin 3 and the form thereof can effectively shield and absorb the radiated light and obtain a desired cooling effect. The absorber 1 may be appropriately modified as long as it is provided. For example, as shown in FIG. 5, the absorber 1 may be such that the inside of the cooling water pipe 2 is partitioned by the cooling fins 3 and 3. Further, the cross-sectional shape of the storage ring to which the absorber of the present invention is applied is not limited to the one having the getter pump chamber 12 as in the above-mentioned embodiment, and the same can be applied to a storage ring having a simple circular or oval cross section. Of course.

[0014]

As described above, in the absorber of the present invention, the cooling water pipe formed of the material capable of absorbing the radiant light is inserted into the storage ring and is arranged at the position for shielding and absorbing the radiant light. The radiant light radiated to the cooling water pipe is shielded and absorbed by the cooling water pipe itself, and the cooling water pipe is cooled by the cooling water passing through it, so a reliable shielding and absorption effect is achieved even with an extremely simple structure. In addition, it is possible to effectively prevent overheating of the cooling water pipe, and there is an advantage that the cooling effect can be further enhanced by forming cooling fins on the inner surface of the cooling water pipe.

[Brief description of drawings]

FIG. 1 is a plan view showing a part of a storage ring including an absorber according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along the line II-II in FIG. 1 for showing the sectional shape of the storage ring.

FIG. 3 is a view showing a cooling water pipe in the absorber.

FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3 for showing a sectional shape of the cooling water pipe.

FIG. 5 is a cross-sectional view showing another example of the cooling water pipe.

[Explanation of symbols]

 1 absorber 2 cooling water pipe 3 cooling fin 10 storage ring B charged particle beam S SOR light (synchronized light)

Claims (2)

[Claims] 1. A radiation accelerator, which is installed at a predetermined position of a storage ring to prevent radiation light emitted from a charged particle beam circulating in the storage ring of a particle accelerator from irradiating the inner wall surface of the storage ring. An absorber for shielding and absorbing light, in which a cooling water pipe through which cooling water passes is made of a material capable of absorbing radiant light, and the cooling water pipe is inserted into a storage ring to shield and absorb radiant light. By arranging the cooling water pipe at a position to be irradiated, the cooling water pipe is irradiated with radiant light, and the radiant light irradiated on the cooling water pipe is shielded and absorbed by the cooling water pipe itself.
An absorber in a particle accelerator, characterized in that the cooling water pipe is configured to be cooled by cooling water passing through the inside. 2. The absorber in a particle accelerator according to claim 1, wherein cooling fins are formed on an inner surface of the cooling water pipe.