Search

CN-121709370-B - Antisymmetric six-pole magnet

CN121709370BCN 121709370 BCN121709370 BCN 121709370BCN-121709370-B

Abstract

The invention provides an antisymmetric six-pole magnet which comprises a pole outer ring, a pole head and an excitation coil. The pole head and the magnetic pole outer ring are integrated, and the pole head and the magnetic pole outer ring comprise three pairs of pole head groups which are uniformly distributed on the inner wall of the magnetic pole outer ring and are arranged opposite to each other, wherein the two pairs of pole head groups respectively comprise two main pole heads which are arranged opposite to each other, and each of the other pairs of pole head groups comprises two auxiliary pole heads with preset intervals. The main pole heads arranged opposite to each other have the same polarity, the auxiliary pole heads with preset intervals have opposite polarities, and the adjacent main pole heads and auxiliary pole heads have opposite polarities. The geometric dimensions of each main pole head are the same, and the sum of the volumes of the auxiliary pole heads with preset intervals is smaller than the volume of each main pole head. The exciting coil is wound on the pole head and is used for providing exciting current for the pole head. The auxiliary pole heads are used for reducing the coupling effect between the main pole heads so as to improve the magnetic field quality of the antisymmetric six-pole magnetic field in the magnetic pole outer ring.

Inventors

  • ZOU YE
  • ZHOU HAO
  • TANG JINGYU
  • ZHANG LINHAO

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260505
Application Date
20260224

Claims (10)

  1. 1. An antisymmetric hexapole magnet, comprising: A magnetic pole outer ring; The pole head comprises three pairs of pole head groups which are uniformly distributed on the inner wall of the magnetic pole outer ring and are arranged opposite to each other, wherein each pair of pole head groups comprises two main pole heads which are arranged opposite to each other, each of the other pairs of pole head groups comprises two auxiliary pole heads with preset intervals, the main pole heads which are arranged opposite to each other have the same polarity, the auxiliary pole heads with the preset intervals have opposite polarities, and the adjacent main pole heads and auxiliary pole heads have opposite polarities; the exciting coil is wound on the pole head and is used for providing exciting current for the pole head; The auxiliary pole head is used for reducing the coupling effect between the main pole heads so as to improve the magnetic field quality of the antisymmetric hexapole magnetic field in the magnetic pole outer ring.
  2. 2. The anti-symmetric hexapole magnet of claim 1, wherein the field coil comprises a first field coil wound on each of the main pole pieces and a second field coil wound on each of the auxiliary pole pieces, the first field coil and the second field coil being controlled by a first power source and a second power source, respectively, independent of each other, to generate a first field current and a second field current.
  3. 3. The antisymmetric hexapole magnet as claimed in claim 2, wherein the magnetic field distribution of a predetermined region of the antisymmetric hexapole magnet is controlled by adjusting the first exciting current and the second exciting current, the predetermined region being a particle distribution region to be extracted in a beam extraction tube within the pole outer ring.
  4. 4. An antisymmetric hexapole magnet as claimed in claim 3, wherein said field coil further comprises: The third excitation coil is wound on the first excitation coil and is positioned at the root of one end of each main pole head close to the outer ring of the magnetic pole, and the third excitation coil is controlled by a third power supply to generate a third excitation current to regulate and control the magnetic field distribution of the antisymmetric six-pole magnetic field; Wherein the third power supply is independent of the first power supply and the second power supply.
  5. 5. An antisymmetric hexapole magnet as claimed in any one of claims 1 to 4, wherein said sub-pole heads having said predetermined intervals are identical in geometric dimension and symmetrical to each other in the radial direction of said pole outer ring, said predetermined intervals being determined based on the accommodation space of said exciting coil wound on each of said sub-pole heads.
  6. 6. The anti-symmetric hexapole magnet of any one of claims 1-4, wherein ends of the main pole head and the auxiliary pole head, which are far from the pole outer ring, are arc-shaped to reduce magnetic field concentration at the ends; The exciting coil exposes the ends of the main pole head and the auxiliary pole head.
  7. 7. The anti-symmetric hexapole magnet of any one of claims 1-4, wherein the length of the pole outer ring in the radial direction is less than or equal to 700mm, and the radius of the beam extraction tube in the anti-symmetric hexapole magnet is less than or equal to 55mm.
  8. 8. An antisymmetric hexapole magnet according to any one of claims 1 to 4, characterized in that the preset spacing between the sub-pole heads is less than or equal to 32mm.
  9. 9. The anti-symmetric hexapole magnet of any one of claims 1-4, wherein a distance between a top of an end of the pole head, which is far from the pole outer ring, and a beam delivery tube in a radial direction of the pole outer ring is greater than or equal to 5mm.
  10. 10. The hexapole magnet of any one of claims 1-4, wherein the shortest distance of the main pole head on the cross section of the beam delivery tube is greater than or equal to 12mm.

Description

Antisymmetric six-pole magnet Technical Field The invention relates to the technical fields of nuclear science, slow resonance extraction of a particle accelerator and nonlinear beam collimation, in particular to an antisymmetric hexapole magnet. Background Compared with a hexapole magnet, the magnetic field formed by the antisymmetric hexapole magnet has stronger anti-electromagnetic source ripple wave jitter capability and higher beam intensity in the aspects of beam resonance slow extraction and nonlinear beam collimation, and can realize higher beam collimation efficiency while improving the beam extraction stability. A common anti-symmetric hexapole magnet is a structure in which a pair of shield plates is disposed between two pairs of magnetic poles to form an anti-symmetric hexapole magnetic field. However, there is a limitation in such a structure, for example, when the aperture of the beam extraction tube is large, in order to satisfy the requirement that the spacing of the shielding plates is larger than the aperture of the beam extraction tube, it is often necessary to design a large magnet structure, resulting in a decrease in the magnetic field quality. Disclosure of Invention In view of the foregoing, embodiments of the present invention provide an antisymmetric hexapole magnet. According to a first aspect of an embodiment of the present invention, there is provided an antisymmetric hexapole magnet comprising a pole outer ring, a pole head and a field coil. The pole head and the magnetic pole outer ring are integrated, and the pole head and the magnetic pole outer ring comprise three pairs of pole head groups which are uniformly distributed on the inner wall of the magnetic pole outer ring and are arranged opposite to each other, wherein the two pairs of pole head groups respectively comprise two main pole heads which are arranged opposite to each other, and each of the other pairs of pole head groups comprises two auxiliary pole heads with preset intervals. The main pole heads arranged opposite to each other have the same polarity, the auxiliary pole heads with preset intervals have opposite polarities, and the adjacent main pole heads and auxiliary pole heads have opposite polarities. The geometric dimensions of each main pole head are the same, and the sum of the volumes of the auxiliary pole heads with preset intervals is smaller than the volume of each main pole head. The exciting coil is wound on the pole head and is used for providing exciting current for the pole head. The auxiliary pole heads are used for reducing the coupling effect between the main pole heads so as to improve the magnetic field quality of the antisymmetric six-pole magnetic field in the magnetic pole outer ring. According to an embodiment of the present invention, the exciting coil includes a first exciting coil wound on each main pole and a second exciting coil wound on each sub pole, the first exciting coil and the second exciting coil being controlled by a first power supply and a second power supply, respectively, independent of each other, to generate a first exciting current and a second exciting current. According to the embodiment of the invention, the magnetic field distribution of the preset area of the antisymmetric hexapole magnet is controlled by adjusting the first exciting current and the second exciting current, and the preset area is a particle distribution area to be led out in a beam current leading-out pipe in the magnetic pole outer ring. According to an embodiment of the invention, the exciting coil further comprises a third exciting coil. The third excitation coil is wound on the first excitation coil and is positioned at the root of one end of each main pole head close to the outer ring of the magnetic pole, and the third excitation coil is controlled by a third power supply to generate third excitation current to regulate and control the magnetic field distribution of the antisymmetric six-pole magnetic field. The third power supply is independent of the first power supply and the second power supply. According to the embodiment of the present invention, the sub-pole heads having the preset interval, which is determined based on the accommodation space of the exciting coil wound on each sub-pole head, are identical in geometry and symmetrical to each other in the radial direction of the pole outer ring. According to the embodiment of the invention, the ends of the main pole head and the auxiliary pole head, which are far away from the outer ring of the magnetic pole, are arc-shaped so as to reduce the concentration of magnetic fields at the ends. The exciting coil exposes the ends of the main pole head and the auxiliary pole head. According to the embodiment of the invention, the length of the magnetic pole outer ring in the radial direction is less than or equal to 700mm, and the radius of the beam extraction pipe in the antisymmetric hexapole magnet is less than or equal to 55mm. According