JPH0636895A - Converging electromagnet of synchrotron and synchrotron having this converging electromagnet - Google Patents

Abstract

PURPOSE:To realize the simplification of power source structure by providing a constitution capable of varying the intensity of converging magnetic field to exciting current, and driving a converging electromagnet and a deflecting electromagnet in series. CONSTITUTION:Magnetic poles 33-36 are constituted movably to a return yolk 32. By turning the bolt 60 of a magnetic pole driving mechanism 55, the magnetic poles 33-36 are moved to vary the intensity of the magnetic field acting on an electron beam 30. The coils 37-40 of converging electromagnets 23, 25 are connected in series to each other, and the coil of a deflecting electromagnet is connected in series thereto. An exciting current for generating a deflecting magnetic field corresponding to the energy of the electron beam is supplied. The bolt 60 is rotated in this state, thereby regulating the magnetic field to an optimum converging magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converging electromagnet of a synchrotron and a synchrotron having the converging electromagnet, which can be driven by a common power source with a deflecting electromagnet by changing the strength of a magnetic field with respect to an exciting current. In this way, simplification of the power supply configuration and control is realized.

[0002]

2. Description of the Related Art In recent years, small synchrotrons are expected to be applied as synchrotron radiation (SOR) devices to various fields such as creation of ultra-ultra LSI circuits, diagnosis in the medical field, molecular analysis, and structural analysis. .

FIG. 2 shows an outline of a small SOR synchrotron radiation device. An electron beam generated by a charged particle generator (electron gun, etc.) 10 is accelerated to near the speed of light by a linear accelerator (linac) 12, deflected by a deflecting electromagnet 16 of a beam transport unit 14, and accumulated via an inflector 18. It is injected into the ring 22. The electron beam incident on the storage ring 22 is supplied with energy in the high-frequency acceleration cavity 21 and is vertically convergent electromagnets 23 (23-1 to 23-4) and horizontal converging electromagnets 25 (25-1 to 25-4). It is converged, deflected by the deflection electromagnet 24 (24-1 to 24-4), and continues to rotate in the storage ring 22. The SOR light generated when being deflected by the deflection electromagnet 24 is sent to, for example, the exposure device 28 through the beam channel 26, and is used as a light source or the like for creating an ultra-super LSI circuit.

The structure of conventional focusing electromagnets 23 and 25 is shown in FIG.
Is shown in the front view. The focusing electromagnets 23 and 25 are quadrupole electromagnets, and a return yoke 32 is arranged so as to surround the vacuum chamber 22 (storage ring) around which the electron beam 30 orbits. The inner peripheral surface of the return yoke 32 projects toward the direction of the electron beam 30 and has four magnetic poles 3.
3 to 36 are formed. Coils 37 to 40 are wound around the magnetic poles 33 to 36, respectively. Each coil 37-
40 is connected in series and an exciting current is supplied from a DC power supply. Depending on how to connect the coils 37 to 40, the magnetic poles 33, 3
When 5 is an N pole and magnetic poles 34 and 36 are S poles, a focusing electromagnet 25 for focusing in the horizontal direction is obtained, and magnetic poles 33 and 35 are S poles.
When the poles and magnetic poles 34 and 36 are excited to the N pole, the focusing electromagnet 23 for vertical focusing is formed. The strength of the magnetic field of the focusing electromagnets 23 and 25 is adjusted by the magnitude of the exciting current.

During operation of the synchrotron, the electron beam 30
Vertical focusing electromagnet 23 and horizontal focusing electromagnet 2 required to correctly orbit the vacuum chamber center orbit
5. The strength of the magnetic field of the deflection electromagnet 24 is different. Therefore, conventionally, each of these electromagnets 23, 24,
Each 25 was driven by a separate excitation power supply. FIG. 4 shows the power supply system, which includes power supply devices 42, 43 and 44 for the electromagnets 24, 23 and 25, respectively.
5,46,47. That is, the deflection electromagnet power supply system 45 includes four deflection electromagnets 24-1 to 24-.
4 coils are connected in series, and an exciting current is supplied from the power supply device 42. In addition, the vertical focusing electromagnet power supply system 46
Connects the coils of four focusing electromagnets 23-1 to 23-4 in series and supplies an exciting current from the power supply device 43. Further, the horizontal focusing electromagnet power supply system 47 connects the coils of the four focusing electromagnets 25-1 to 25-4 in series, and supplies an exciting current from the power supply device 44.

[0006]

According to the structure of the focusing electromagnets 23 and 25 shown in FIG. 3, the strength of the magnetic field is determined by the magnitude of the exciting current. Therefore, the vertical focusing electromagnet 23, the horizontal focusing electromagnet 25, and the deflection electromagnet 24 cannot be driven by a common exciting current, and the power supply system is as shown in FIG.
As described above, since the electromagnets 23 and 24 must be provided independently, there is a drawback that the power supply configuration and its control are complicated.

The present invention solves the above problems in the prior art and makes it possible to vary the strength of the magnetic field with respect to the exciting current so that the power source common to the deflecting electromagnet can be driven, and the power source configuration and control can be improved. An object of the present invention is to provide a focusing electromagnet of a synchrotron that realizes simplification and a synchrotron including the focusing electromagnet.

[0008]

A focusing electromagnet of the present invention includes a return yoke arranged so as to surround a vacuum chamber in which a particle beam orbits, and approaches and separates from a central orbit around the vacuum chamber. A plurality of magnetic poles that are attached to and supported by the return yoke as much as possible, coils arranged around these magnetic poles, and a magnetic pole drive mechanism that drives the magnetic poles toward and away from the central trajectory of the vacuum chamber. It is equipped with and. Further, the synchrotron of the present invention includes a plurality of focusing electromagnets having the above-mentioned configuration, a plurality of deflection electromagnets disposed at respective deflection positions of the vacuum chamber, coils of the plurality of focusing electromagnets, and a plurality of the deflection electromagnets. An exciting current supply system is provided, in which coils are connected in series and an exciting current is supplied from a common power supply device.

[0009]

According to the converging electromagnet of the present invention, since the magnetic poles are arranged so as to be able to approach and separate from the particle beam orbit, the strength of the magnetic field acting on the particle beam changes depending on the approach distance, and the magnetic field for the exciting current is changed. The strength can be changed.

Further, according to the synchrotron of the present invention, since the strength of the converging magnetic field can be adjusted while the focusing electromagnet is driven by the exciting current from the power supply device common to the deflection electromagnet, the power supply configuration and control are simplified. Can be converted.

[0011]

【Example】

(Embodiment 1) FIG. 1 is a front view showing an embodiment of a focusing electromagnet of the present invention. The focusing electromagnets 23 and 25 are quadrupole electromagnets, and a return yoke 32 is arranged so as to surround the vacuum chamber 22 (storage ring) around which the electron beam 30 orbits. Recesses 51 to 54 are formed on the inner peripheral side of the return yoke 32, and the magnetic poles 33 to 36 are movably accommodated therein. Each magnetic pole 33-36
Is moved as shown by arrow B by the magnetic pole drive mechanisms 55 to 58, and the approach distance to the electron beam 30 is adjusted. The coils 37 to 40 are wound around the magnetic poles 33 to 36, respectively, while being fixed to the return yoke 32 (not fixed to the magnetic poles 33 to 36).

In the magnetic pole drive mechanisms 55 to 58, the bolt 60 is rotatably attached to the wall 32a of the return yoke 32, and the threaded portion 60a is passed through the recess 51. A ball hole 62 is formed at the rear end of the magnetic poles 33 to 36, and a screw portion 60a is screwed into the ball hole 62. With such a configuration, by rotating the bolt 60 with a tool, the magnetic poles 33 to
By moving 36 in the direction of arrow B, the strength of the converging magnetic field acting on the electron beam 30 with respect to the exciting current can be adjusted.

The focusing electromagnets 23 and 25 shown in FIG. 1 are made vertical 23 and horizontal 25 by winding and connecting the coils 37 to 40. That is, when the coils 37 to 40 are wound and connected as shown in FIG. 5A to excite the magnetic poles 33 and 35 to the N pole and the magnetic poles 34 and 36 to the S pole, the focusing electromagnet 25 for the horizontal focusing is obtained. In addition, as shown in FIG.
By winding 7 to 40 and connecting them to excite the magnetic poles 33 and 35 to the S pole and the magnetic poles 34 and 36 to the N pole, the focusing electromagnet 23 for vertical focusing is formed.

Next, FIG. 6 shows an embodiment of the exciting power supply system of the synchrotron of FIG. 2 when the focusing electromagnets 23 and 25 of FIG. 1 are used. The coils of the focusing electromagnets 23 and 25 are connected, for example, as shown in FIG. In addition, the deflection electromagnet 24 has an electron beam 30 as shown in FIG.
The magnetic poles 66 and 68 are arranged so as to face each other across the orbit, and the coils 70 and 72 are wound around the magnetic poles 66 and 68, respectively. The coils 70 and 72 are connected in series and a direct current is supplied. As a result, the magnetic poles 70 and 72 are N
It is excited by the pole and the S pole to generate a magnetic field in the vertical direction and give a deflection force to the electron beam 30.

In the power supply system 71 of FIG. 6, the deflection electromagnets 24 and the focusing electromagnets 23 and 25 are all connected in series in the order of arrangement in FIG. 2 and connected to a common DC power supply device 70. The magnetic field is adjusted by the following procedure, for example.

The current value supplied from the power supply device 70 is set to a current value at which the deflection electromagnet 24 generates a deflection magnetic field corresponding to the energy of the electron beam 30.

The magnetic field adjusting bolts 60 of the focusing electromagnets 23 and 25 are turned to move the focusing electromagnets 23 and 25 under the above current value.
The magnetic field strength of 25 is adjusted to the optimum state. The angle at which the bolt 60 is turned is adjusted so that the magnetic poles 33 to 36 have the same gap with respect to the outer peripheral surface of the vacuum chamber 22 if there is no installation or manufacturing error of the focusing electromagnets 23 and 25.

For the final adjustment, the betatron frequency (determined by the deflection magnetic field and the converging magnetic field) of the electron beam 30 is measured by a tune monitor, and the bolt 60 is rotated to obtain a desired betatron frequency. adjust.

After the above setting, if the electron beam is made to enter the full energy, the electron beam 30 can be orbitally accumulated on the orbit of the accumulation ring and accumulated.

(Embodiment 2) FIG. 8 shows another embodiment of the converging electromagnet of the present invention. This is one in which the movement of the magnetic poles is automated and the magnetic field can be adjusted by remote control. The same parts as those in the embodiment of FIG. 1 are designated by the same reference numerals. The magnetic pole drive mechanisms 55 to 58 will be described. The bolt 60 is rotatably attached to the return yoke 32. A gear 72 is attached to the rear end of the bolt 60. A pulse motor 76 is attached to the outer peripheral portion of the return yoke 32, and its rotation is transmitted to the gear 72 via the gear 74. The gap control device 78 inputs the gap command value and receives the pulse motor 76 of each magnetic pole drive mechanism 55.
By rotating the same amount, the gap g between the magnetic poles 33 to 36 and the outer peripheral surface of the vacuum chamber 22 is adjusted to be equal. Also,
It is also possible to finely adjust each magnetic pole 33 to 36. With such a configuration, the magnetic field strength can be adjusted by remote control.

[0021]

As described above, according to the converging electromagnet of the present invention, since the magnetic poles are arranged so as to be able to approach and separate from the particle beam trajectory, the strength of the magnetic field acting on the particle beam depends on the approach distance. It is possible to change and change the strength of the magnetic field with respect to the exciting current.

Further, according to the synchrotron of the present invention, since the strength of the converging magnetic field can be adjusted while the focusing electromagnet is driven by the exciting current from the power supply device common to the deflection electromagnet, the power supply configuration and control are simplified. Can be converted.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a focusing electromagnet of the present invention.

FIG. 2 is a plan view showing an outline of an SOR device.

FIG. 3 is a front view showing a conventional focusing electromagnet.

FIG. 4 is a power supply system diagram of a focusing electromagnet and a deflection electromagnet of a conventional synchrotron.

5 is a diagram showing an example of horizontal and vertical coil connections in the converging electromagnet of FIG. 1. FIG.

FIG. 6 is a diagram showing an embodiment of a power supply system for the focusing electromagnet and the deflection electromagnet of the synchrotron according to the present invention.

FIG. 7 is a diagram showing an example of coil connection of a bending electromagnet.

FIG. 8 is a front view showing another embodiment of the focusing electromagnet of the present invention.

[Explanation of symbols]

22 vacuum chamber 23 focusing electromagnet (for vertical) 24 deflection electromagnet 25 focusing electromagnet (for horizontal) 30 electron beam (particle beam), vacuum chamber central orbit 32 return yoke 33-36 magnetic pole 37-40 coil 55-58 magnetic pole drive mechanism 70 Power supply 71 Power supply system (excitation current supply system)

Claims (2)

[Claims] 1. A return yoke which is arranged so as to surround a vacuum chamber in which a particle beam orbits, and which is close to a central orbit around the vacuum chamber,
A plurality of magnetic poles attached to and supported by the return yoke in a separable manner, coils arranged around these magnetic poles, and magnetic pole drive for driving the magnetic poles in directions approaching and separating from the central trajectory of the vacuum chamber. A focusing electromagnet with a mechanism. 2. A return yoke arranged so as to surround a vacuum chamber in which a particle beam circulates, and a plurality of return yokes attached to and supported by the return yoke so as to be able to approach and separate from a central orbit around the vacuum chamber. Magnetic poles of
A plurality of focusing electromagnets each including a coil disposed around each of the magnetic poles, and a magnetic pole drive mechanism that drives each of the magnetic poles toward and away from the central trajectory of the vacuum chamber, and each of the vacuum chambers. A plurality of deflection electromagnets arranged at a deflection position, a plurality of focusing electromagnet coils, and a plurality of deflection electromagnet coils connected in series, and an excitation current supply system for supplying an excitation current from a common power supply device. A synchrotron equipped.