JPH07183121A - Deflecting electromagnet - Google Patents

Abstract

PURPOSE:To prevent an eddy current from being generated by a change with time in a magnetic field and to suppress the effect of a magnetic saturation in a high magnetic field in a deflecting electromagnet. CONSTITUTION:In a deflecting electromagnet formed into a structure that a coil 13 is wound on a core and a deflecting magnetic field, which is formed by charged particles, such as electrons and ions, is generated, the core is constituted of a laminated core 11 formed by laminating a plurality of magnetic plates along a beam directional axis and a block core 12, which is inserted in a space formed by cutting off the center part in the laminated direction of this core 11 and is bonded integrally with the core 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a particle accelerator,
The present invention relates to a deflection electromagnet used for deflecting charged particles such as electrons and ions.

[0002]

2. Description of the Related Art In a particle accelerator such as an electron storage ring, when a target charged particle has a large energy and a small size is required, a deflection electromagnet used in the particle accelerator has a large deflection angle and a high magnetic field. Must be generated on the charged particle beam orbit.

FIG. 7 shows a conventional bending electromagnet. As shown in FIG. 7, this deflection electromagnet is composed of a substantially C-shaped block core 1 and a coil 2 wound around magnetic pole portions projecting in directions opposite to each other from the tips of the legs of the block core 1. There is.

FIG. 8 shows a conventional bending electromagnet for particle acceleration, which is different from that shown in FIG. This bending electromagnet
As shown in FIG. 8, a laminated iron core 3 having C-shaped magnetic plates laminated along the axis of the beam direction (laminated so that the plane has a fan shape) is used as an iron core structure, and the laminated iron core 3 faces each other from the tip ends of the legs. The coil 2 is wound around a magnetic pole portion protruding in the direction.

[0005]

In the conventional bending electromagnet used for the particle accelerator, there is a case where the deflection angle is particularly large, the magnetic field is high, and the magnetic field accuracy is required. However, in the bending electromagnet using the block iron core 1 shown in FIG. 7, an induced voltage is generated in the iron core when it is exposed to an environment where the magnetic field changes with time, which causes an eddy current to flow in the iron core. Therefore, the magnetic field formed by the eddy current changes the magnetic flux density in the gap and its distribution, and also affects the residual magnetic field.

Further, in the bending electromagnet using the block iron core 1 shown in FIG. 8, although the influence of the eddy current is eliminated, when the beam polarization angle is large, a plurality of magnetic plates are stacked along the beam direction axis. In this case, that is, when the layers are laminated so that the planes are fan-shaped, the space factor of the iron core seam portion in the central portion becomes low, and there is an influence of magnetic saturation due to the decrease of the iron core permeability in a high magnetic field.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a bending electromagnet capable of suppressing the influence of magnetic saturation in a high magnetic field without generating an eddy current due to a temporal change of a magnetic field. The purpose is to

[0008]

In order to achieve the above object, the present invention comprises a bending electromagnet by the following means. (1) In a deflection electromagnet in which a coil is wound around an iron core to generate a deflection magnetic field of charged particles such as electrons and ions, a laminated iron core in which a plurality of magnetic plates are laminated along a beam direction axis,
The core is composed of a block core that is inserted into a space formed by cutting and removing the central portion of the laminated core in the laminating direction and integrally joined to the laminated core. (2) In a bending electromagnet in which a coil is wound around an iron core to generate a bending magnetic field of charged particles such as electrons and ions, a laminated iron core in which a plurality of magnetic plates are laminated in a straight line and both end faces in the laminating direction of the laminated iron core The core is composed of a block core that is integrally joined to the block core and has a plane in which the central orbit of the beam and the end face of the core are perpendicular to each other and has a substantially triangular shape. (3) In a deflection electromagnet in which a coil is wound around an iron core and which generates a deflection magnetic field of charged particles such as electrons and ions, a plurality of divided block iron cores obtained by dividing the block iron core along the beam direction axis are superposed on each other. The iron core is formed by joining together.

[0009]

In the bending electromagnet having the structure as described in (1) above, the block core is inserted into the space formed by cutting and removing the central portion of the laminated core, and the cores are joined and integrated. Because of the structure, the space factor and magnetic permeability of the entire core can be improved as compared with the conventional laminated core.
Therefore, even if the deflection angle is large, the magnetic field is high, and the accuracy of the magnetic field is required, it can be dealt with.

In the bending electromagnet having the above-mentioned structure (2), even if the laminated cores are stacked in a straight line,
Since a gap is not created between the stacked layers to reduce the magnetic permeability, it is possible to maintain high magnetic permeability even in a high magnetic field and suppress magnetic saturation.

In the deflecting electromagnet having the above-mentioned structure (3), since the block iron cores have a single and independent structure, eddy currents flowing through the iron core are hardly generated.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view showing a first embodiment of a bending electromagnet according to the present invention, and FIG. 2 is a top view of an iron core in the same embodiment.

In FIGS. 1 and 2, a plurality of substantially C-shaped magnetic plates are laminated as an iron core along the axis B in the beam direction (laminated so that the plane has a fan shape), and the laminated iron core 11 is laminated. The block core 12 having a substantially C-shape inserted into a space formed by cutting and removing the central portion in the direction is joined to be integrated. Then, the coil 13 is wound around the magnetic pole portions protruding from the tip ends of the leg portions of the laminated iron core 11 and the block iron core 12 in the mutually facing directions.

Here, a case of manufacturing the laminated core 11 will be described. First, as in the conventional case, a plurality of magnetic plates are laminated along the axis of the beam direction to manufacture an integrated laminated core. As shown by the broken line in FIG. 2, this integral laminated iron core has a low core space factor in the substantially triangular portion in the central portion in the laminating direction. Therefore, the substantially rectangular portion having the width shown in FIG. Then, the separately manufactured block iron core 12 is inserted into the space of the removed portion. Then, the block core 12 and the laminated cores 11 on both sides, which are the remaining portions after the width W portion is removed, are integrally joined by means such as welding.

In the bending electromagnet having such a structure,
Since the block core 12 is inserted into the space formed by cutting and removing the central portion of the laminated core 11 and these are joined together to form an integral core structure, compared to the conventional laminated core, the entire core is occupied. The product ratio and magnetic permeability can be improved.
Therefore, even if the deflection angle is large, the magnetic field is high, and the accuracy of the magnetic field is required, it can be dealt with.

FIG. 3 is a perspective view showing a second embodiment of the bending electromagnet according to the present invention, and FIG. 4 is a top view of the iron core in the same embodiment. 3 and 4, a laminated iron core 21 in which a plurality of substantially C-shaped magnetic plates are laminated in a straight line as an iron core, and a central orbit of a beam and end faces of the iron core which are provided at both ends of the laminated iron core 21 in the laminating direction are shown. A C-shaped block iron core 22 having a substantially triangular shape formed to be at a right angle
And a laminated core 21 and a block core 22.
The coil 23 is wound around the magnetic pole portions projecting from the tips of the legs in the directions facing each other.

Here, when the laminated core 21 is manufactured, first, the substantially C-shaped magnetic plates are laminated in a straight line, and the laminated core in which these are integrated is manufactured, and the laminated core is used as the beam center of the beam. C-shaped block cores 22 each having a substantially triangular plane are provided on both sides of the laminated core 21 so that the end faces of the cores are perpendicular to each other, and these are integrally joined.

In the bending electromagnet having such a structure,
Even if the laminated cores 21 are stacked in a straight line, no gap is created between the laminated layers to reduce the magnetic permeability. That is, the magnetic permeability of the entire iron core can be made higher than that of the conventional laminated iron core, the high magnetic permeability can be maintained even in a high magnetic field, and the magnetic saturation can be suppressed.

Further, by making the end face of the magnet at a right angle regardless of the beam trajectory, the beam converges (diverges) at the end.
No force is generated. FIG. 5 is a perspective view showing a third embodiment of the bending electromagnet according to the present invention, and FIG. 6 is a top view of the iron core in the same embodiment.

In FIG. 5 and FIG. 6, a block core 31 as an iron core is divided into a plurality of substantially C-shaped divided block cores 31a along the axis of the beam direction so as to be superposed so as to be integrated. The coil 32 is wound around the magnetic pole portions projecting from the tips of the leg portions of the divided block iron core 31a so as to face each other.

In the deflecting electromagnet having such a structure,
Since each block iron core 31 has a single independent structure, eddy currents flowing through the iron core hardly occur.

[0022]

As described above, according to the present invention, the eddy current is not generated in the transient state of the magnetic field, and the influence of the magnetic saturation of the iron core due to the high magnetic field can be suppressed, so that the magnetic field is changed according to the beam energy. It is possible to provide a bending electromagnet capable of improving the magnetic field following property and maintaining the homogeneity of the magnetic field even in the coercive field.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a bending electromagnet according to the present invention.

FIG. 2 is a top view of the iron core according to the same embodiment.

FIG. 3 is a perspective view showing a second embodiment of the bending electromagnet according to the present invention.

FIG. 4 is a top view of the iron core according to the embodiment.

FIG. 5 is a perspective view showing a third embodiment of the bending electromagnet according to the present invention.

FIG. 6 is a top view of the iron core according to the same embodiment.

FIG. 7 is a perspective view showing a conventional bending electromagnet.

FIG. 8 is a perspective view showing another conventional bending electromagnet.

[Explanation of symbols]

11, 21 ... laminated core, 12, 22 ... block core, 13, 23, 32 ... coil, 31 ... block core, 31a ... divided block core.

Claims (3)

[Claims] 1. In a deflection electromagnet, in which a coil is wound around an iron core to generate a deflection magnetic field of charged particles such as electrons and ions, a laminated iron core in which a plurality of magnetic plates are laminated along a beam direction axis, and the laminated iron core. A bending electromagnet, comprising: a block core that is inserted into a space formed by cutting and removing the central portion in the stacking direction and integrally joined to the stacked core. 2. In a bending electromagnet, in which a coil is wound around an iron core to generate a bending magnetic field of charged particles such as electrons and ions, a laminated iron core in which a plurality of magnetic plates are laminated in a straight line and a laminating direction of the laminated iron core. A bending electromagnet, characterized in that the iron core is composed of a block iron core having a plane which is integrally joined to both end faces and is formed so that the central orbit of the beam and the end face of the iron core form a right angle. 3. A deflection electromagnet having a coil wound around an iron core to generate a deflection magnetic field of charged particles such as electrons and ions, wherein a plurality of divided block cores obtained by dividing the block core along the beam direction axis are superposed. A bending electromagnet, characterized in that the iron core is formed by integrally joining these.