JP2569928B2 - Quadrupole magnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention corrects the position of an electron beam in a vacuum duct in a synchrotron for obtaining a high-energy electromagnetic wave by drawing an arc on the high-energy electron beam. The present invention relates to a quadrupole electromagnet as a correction electromagnet for performing the correction.

[Conventional technology]

The synchrotron is a device that accelerates while rotating charged particles by arranging electromagnets in a circular shape, and is particularly suitable for obtaining high-energy charged particles, and is used as a particle accelerator in research on high-energy particles. In recent years, utilization of high-energy electromagnetic waves generated by synchrotron radiation of high-energy electrons generated by a synchrotron has been advanced in various fields.

FIG. 5 is a plan view schematically showing the entire synchrotron. In this figure, the synchro-son is provided with six bending electromagnets 150, two quadrupole electromagnets 140 provided two each between these bending electromagnets 150, and six beam position monitors 130 provided between the bending electromagnets 150 and the quadrupole electromagnets 140. , And a vacuum duct 100 indicated by one straight line as a traveling path of an electron beam connecting them, and an electron incidence duct 210 and an electron extraction duct 220 are provided.

An electron beam accelerated separately to a predetermined energy value is incident on the synchrotron from the electron entrance duct 210. The incident electron beam is further accelerated or circulates in the vacuum duct 100 of the synchrotron, or retains the energy at the time of incidence.

The electron beam in the vacuum duct 100 goes around a circulating orbit determined according to the magnetic field of the bending electromagnet 150. This circulating orbit is designed to pass exactly through the center of the vacuum duct 100, but in reality, there are errors such as installation errors of the bending electromagnet 150 and the quadrupole electromagnet 140 for converging the electron beam and variations in the magnetic field strength. Deviates from the above-mentioned design circular orbit. The beam position monitor 130 automatically corrects this deviation and constantly measures the position of the electron beam so as to maintain the position of the electron beam at the center of the vacuum duct.

The beam position monitor 130 is installed at a plurality of locations,
By calculating the output values of these beam position monitors 130, the beam position at each location is obtained. By analyzing the results and adjusting the magnetic field strength of the electromagnetic field, the circulation trajectory of the electron beam is corrected.

FIG. 6 is an elevation view of a quadrupole electromagnet. Quadrupole electromagnet is T
Magnetic pole part 111,121,1 at the center of iron core 11,12,13,14 with the following cross section
As shown, four unit electromagnets 10, 20, 30, 40 in which excitation coils 21, 22, 23, 24 are wound around 31,141 are used as excitation coils 21, 22, 2, 2 as shown.
It is assembled in a square shape with 3,24 inside. A vacuum duct 100 is disposed at the center of the quadrupole electromagnet, and the electron beam travels in a direction perpendicular to the plane of the drawing. The respective magnetic pole portions 111, 121, 131, 141 project toward each other toward the vacuum duct 100, and a current is supplied to the exciting coils 21, 22, 23, 24 so that adjacent magnetic fluxes are generated in opposite directions, so that a so-called quadrupole magnetic field is evacuated. The quadrupole magnetic field is generated in the space including the duct 100, and functions to return electrons shifted from the normal beam position in the vacuum duct 100 to the normal position.

The magnetic field generated by the quadrupole electromagnet is a changing magnetic field, and the changing speed may be as high as the commercial frequency in some cases. Therefore, various attempts have been made to minimize the eddy current generated in the iron core. The cores 11, 12, 13, and 14 are made of a silicon steel sheet having a surface coated with an inorganic insulating film and having a T-shaped inside as shown in the figure, and having a predetermined width dimension in the direction perpendicular to the paper of FIG. It is formed by laminating to the thickness, and such an iron core is generally adopted for AC rotating machines and transformers, and has a configuration that suppresses eddy current as much as possible against a time-varying magnetic field. Well known as

The iron core 11 includes a yoke portion 112 whose both ends are bent inward by 45 degrees, and a magnetic pole portion 111 protruding inward from the center of the yoke portion 112.
Are wound to form the unit magnet 10, and the other three unit electromagnets 20, 30, and 40 are also the same.

Iron cores 11,12,1 which are also the connection between unit magnets 10,20,30,40
The connection between 3,14 is performed at the connection parts 31,32,33,34,
The yoke portions 112, 122, 132, 142 are formed into a cylindrical shape whose axial direction is perpendicular to the drawing by this connection.

FIG. 7 is a plan view of a conventional excitation coil 21, FIG. 8 is a side view thereof, and FIG. 9 is an elevation view thereof.
It is common to 2,23,24. In these drawings, as shown in FIG. 7, the cross-sectional shape of the plane of the magnetic pole portion 111 is substantially rectangular, and the exciting coil 21 is also a rectangular coil correspondingly. The side view in FIG. 8 corresponds to the viewing direction in FIG.

Reference numerals 211 and 212 denote lead leads for the exciting coil 21, and winding leads of the exciting coil 21 are lead leads 211. The winding start position is clearly shown in FIG.
The lead-out lead 212 is located at the innermost layer adjacent to both the magnetic pole portion 2 and the magnetic pole portion 111, and is located at the winding end position, and the position is the outermost layer. If the direction connecting the yoke portion 112 side and the tip of the magnetic pole portion 111 is called an axial direction, this axial direction is the eighth direction.
It becomes the left and right direction in the figure. The conductor constituting the exciting coil has a square cross section as shown in the figure, and is arranged side by side in the axial direction to form a first layer by winding a predetermined number of turns. The second layer is formed by sequentially winding in a direction and winding a predetermined number of turns. The movement of the conductor 213 in the axial direction or to the next layer depends on the side between the positions where the extraction leads 211 and 212 are extracted,
That is, all the operations are performed on the right side of FIG.

FIG. 10 is a cross-sectional view showing a winding order when the exciting coil 21 is wound. This cross-sectional view is common to all positions except the right-hand side in FIG. In this figure, the excitation coil 21
The conductor 213 has a circular cooling hole (not shown) provided in the center and has a square cross-sectional shape, and the cooling hole is efficiently cooled by passing cooling water through the cooling hole. The size of the coil 21 is reduced, and the size of the quadrupole electromagnet itself is reduced.

The winding order is shown by numbering each conductor. The beginning of winding is the lower left position in the figure adjacent to the magnetic pole part 111 and the yoke part 112 indicated by the winding number 1. After this, the magnetic pole part 111
The first layer is formed by winding 7 turns along the surface of the first layer, and the winding number 8 is wound by changing the position on the conductor 213 of the last winding number 7 of this layer. The movement of the position from the winding number 7 to the winding number 8 is performed on the right side of FIG. 7 as described above.
The second layer starts with winding number 8 and ends with winding number 13.
The winding number 13 is above the winding number 2 and the lead 21
Since it is impossible to wind above winding number 1 because 1 is in the way, the second layer must be ended with winding number 13 as described above. In the same way, the third layer starts from winding number 13.
The 18th and 4th layers have winding numbers 19 to 22, and the 5th outermost layer has winding numbers 23 to 25, completing a total of 25 turns of the exciting coil 21. The position of the winding number 25 at the end of the winding is also the position where the extraction lead 212 is pulled out. Similarly to the second layer, the third and subsequent layers cannot be wound on the winding number 1, so that this portion is a cavity in which the conductor 213 cannot be provided. Actually, an insulator is inserted to secure mechanical strength such as enduring the electromagnetic force applied to the exciting coil. The number of turns in the third and subsequent layers is sequentially reduced because, as shown in FIG. In order to escape.

[Problems to be solved by the invention]

As described above, the drawer lead 211, which is the beginning of winding, is in the way, and a cavity corresponding to one conductor 213 is formed above the conductor of winding number 1 at a position adjacent to the yoke portion 112, and as a result, it is excited. There is a problem that the space factor of the coil 21 decreases and the required cross-sectional dimension increases, resulting in an increase in the size of the quadrupole electromagnet. Further, although an insulator is inserted into the hollow portion where the winding is impossible, there is a problem that it is more difficult to secure dimensional accuracy than when the conductor 213 is filled.

An object of the present invention is to solve such a problem and to provide a quadrupole electromagnet having an exciting coil that can improve the space factor and easily secure dimensional accuracy.

[Means for solving the problem]

According to the present invention, an exciting coil is wound around each of four magnetic pole portions provided symmetrically with the tip end inside on the inner diameter side of a cylindrical yoke. In these quadrupole electromagnets, these exciting coils are formed in a predetermined number of turns by laminating a plurality of layers formed by winding and arranging conductors in an axial direction as a direction connecting the yoke side of the magnetic pole portion and the tip portion, The exciting coil has a winding start position adjacent to the innermost yoke portion, and a predetermined number of turns for each layer other than the innermost layer except for one conductor at a position adjacent to the yoke portion. After winding, the winding direction is reversed, and a predetermined number of turns are wound at a position adjacent to the yoke portion so as to overlap the winding start conductor.

[Action]

In the configuration of the present invention, the position of the winding start conductor of the exciting coil is set to the position adjacent to the innermost yoke adjacent to the magnetic pole portion, and the other layers than the innermost layer are set at the positions adjacent to the yoke. By winding a predetermined layer except for a conductor portion, and then winding the winding direction in reverse and overlapping the above-described winding start conductor and winding a predetermined number of turns at a position adjacent to the yoke, a yoke portion Since the conductor can be wound at a position adjacent to the coil, the space factor of the exciting coil is improved by the number of turns and the cavity is eliminated.

〔Example〕

Hereinafter, the present invention will be described based on examples. FIG. 1 is a cross-sectional view showing the winding sequence of an exciting coil according to an embodiment of the present invention. The detailed description of the components common to FIG. 10 is omitted by attaching the same reference numerals.
In this figure, the winding number 1 of the exciting coil 21A is the position of the winding start conductor. Hereinafter, up to the winding number 22 without a minus sign, the winding method is basically the same as that of FIG. It is wound. The winding number 22 is also a pull-out position of a pull-out lead 212A described later. However, the lead 211A is not at the position of the winding number 1.

After fixing the drawer lead 212A so as not to rewind, three turns of winding numbers -1 to -3 with a minus sign in the figure are wound. Before starting the winding of the winding numbers 1 to 22, the three turns of the conductor are appropriately wound in advance on a winding frame so as not to hinder the rotation of a winding frame (not shown). After fixing the above-mentioned lead 212A, the lead 212A is once rewound and then wound on the conductor of winding number 1 at a position adjacent to the yoke 112 as shown in the figure. At the time of this winding, there is no obstacle to winding, and winding of the conductors with winding numbers -1 to -3 is easy. The position of the lead 211A is the position of the winding number-3 as described later. The total number of turns of the exciting coil 21A is 25 turns in accordance with FIG. In this case, the number of layers of the exciting coil 21 in FIG. 10 is five, whereas in FIG. 1, the number is four and the number of layers is reduced by one.

FIG. 2 is a plan view of the exciting coil 21A wound based on the winding order shown in FIG. 1, FIG.
The figure is also a side view and is similar to FIGS. 7, 8 and 9, respectively. As apparent from these figures, the lead 212A as the winding end of the exciting coil 21A
Is not much different from the position of the lead 212 of the exciting coil 21 as the conventional example shown in FIGS. 7 to 9. FIG. However, the other lead 211A is located adjacent to the yoke 112 and in the outermost layer, and
Both 1A and 212A are the outermost layers and these lead leads 211
The configuration of a connection lead (not shown) for connecting A and 212A is also simplified. Since conductors are densely arranged also at positions adjacent to the yoke portion 112, the required cross-sectional dimension of the excitation coil 21A can be reduced in order to improve the space factor of the excitation coil 21A, and the yoke 112 And the size of the quadrupole electromagnet itself can be reduced, thereby conserving materials and reducing the price of the quadrupole electromagnet. In addition, since a hollow portion having no conductor does not occur in the portion adjacent to the yoke portion 112, the mechanical strength is enhanced and the dimensional accuracy of the exciting coil 21A is easily ensured as compared with the case where the insulator is packed.

〔The invention's effect〕

According to the present invention, as described above, the position of the winding start conductor of the excitation coil is set to a position adjacent to the innermost yoke adjacent to the magnetic pole portion, and one of the positions adjacent to the yoke with respect to layers other than the innermost layer is set. By winding a predetermined layer except for a conductor portion, and then winding the winding direction in reverse and overlapping the above-described winding start conductor and winding a predetermined number of turns at a position adjacent to the yoke, a yoke portion Since the conductor can be wound at a position adjacent to the coil, the effect of improving the space factor of the exciting coil by the number of turns can be obtained. As a result, the required cross-sectional dimensions of the excitation coil can be reduced, and the dimensions of the yoke and the dimensions of the quadrupole electromagnet itself can be reduced, thereby saving material and reducing the price of the quadrupole electromagnet. A ripple effect is obtained that is possible. In addition, since a hollow portion having no conductor does not occur in the portion adjacent to the yoke portion, it becomes mechanically stronger as compared with the case where the insulator is packed, and the dimensional accuracy of the exciting coil is easily secured. Further, since all the extraction leads of the excitation coil are drawn out from the outermost layer, an additional effect that the configuration of the connection leads connecting these extraction leads is simplified can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a winding sequence of an exciting coil of a quadrupole electromagnet showing an embodiment of the present invention, and FIG. 2 is a plan view of an exciting coil wound based on FIG. , FIG. 3 is an elevation view,
FIG. 4 is a side view, FIG. 5 is a plan view schematically showing the entire synchrotron, FIG. 6 is an elevation view of a quadrupole electromagnet, FIG.
The figure is a plan view showing an exciting coil of a conventional quadrupole electromagnet, and FIG.
FIG. 9 is a side view, FIG. 9 is an elevation view, and FIG. 10 is a cross-sectional view showing the winding sequence of a conventional quadrupole electromagnet with an exciting coil. 10,20,30,40… Unit electromagnet, 11,12,13,14 …… Iron core, 111,121,131,141 …… Pole section, 112,122,132,142… Yoke section, 21,21A, 22,23,24 …… Exciting coil, 211,212,211A, 212A ... lead-out lead, 213 ... conductor.

Claims (1)

(57) [Claims] An exciting coil is wound around each of four symmetrically provided magnetic pole portions with a tip portion inside on the inner diameter side of a cylindrical yoke. In a quadrupole electromagnet formed by stacking a plurality of layers formed by arranging and winding conductors in an axial direction as a direction connecting the yoke side of the magnetic pole portion and the tip portion to a predetermined number of turns, the exciting coil has a winding start. Is defined as a position adjacent to the innermost yoke portion, and a predetermined number of turns is wound on each layer other than the innermost layer except for one conductor at a position adjacent to the yoke portion. The quadrupole electromagnet is formed by winding a predetermined number of turns at a position adjacent to the yoke portion so as to overlap the winding start conductor.