CN-224218566-U - Quadrupole magnet and particle accelerator

CN224218566UCN 224218566 UCN224218566 UCN 224218566UCN-224218566-U

Abstract

The utility model relates to the technical field of particle accelerators, in particular to a quadrupole magnet and a particle accelerator, wherein the quadrupole magnet comprises a first frame, a second frame and four independent winding coils wound between the two frames, the first frame and the second frame are symmetrical closed frames, are arranged in parallel at intervals and are rotationally symmetrical around a particle beam channel positioned in the center of the two frames; each independent winding coil comprises two transverse bending sections and two longitudinal acting sections, wherein an interval space is formed between the two longitudinal acting sections of the same independent winding coil, and the longitudinal acting sections of at least one other independent winding coil are arranged in the interval space, so that the geometric length of the transverse bending sections is expanded through the increase of extension paths. Through the rotation symmetry layout of the symmetrical closed frame, the extension type winding path of the transverse bending section and the collaborative filling design of the multi-coil interval space, the defect of the traditional acute angle bending process is avoided, and meanwhile, the limited space is utilized to the maximum extent.

Inventors

XIAO MINGMING
WU WEI
ZHU SIHUA
Dong Ruixue
LIN QIHANG
CHEN YUAN
ZHANG WENZHI

Assignees

上海艾普强粒子设备有限公司

Dates

Publication Date: 20260508
Application Date: 20250526

Claims (10)

1. A quadrupole magnet, includes first frame, second frame and winds four independent winding coils between two frames, its characterized in that: The first frame and the second frame are symmetrical closed frames, are arranged in parallel at intervals and are rotationally symmetrical around a particle beam flow channel positioned in the center of the two frames; Each independent winding coil includes: two sections of transverse bending sections respectively extend, wind and are fixed at the corresponding edge parts of the first frame and the second frame; The two longitudinal acting sections are bridged between the transverse bending sections and extend along the axial direction of the central particle beam channel and are used for generating a quadrupole magnetic field; And a spacing space is formed between two longitudinal acting sections of the same independent winding coil, and at least one longitudinal acting section of other independent winding coils is arranged in the spacing space, so that the geometric length of the transverse bending section is expanded through the increase of an extension path.
2. A quadrupole magnet according to claim 1, characterized in that, The symmetrical closed frame is a square frame; The longitudinal acting sections of the four independent winding coils are respectively distributed along four edge parts of the square frame, two longitudinal acting sections are correspondingly distributed on each edge part, and the two longitudinal acting sections belong to different independent winding coils; The longitudinal acting sections of the opposite sides are symmetrically arranged in geometric positions and current directions to generate symmetrical quadrupole magnetic fields in the central particle beam flow channel.
3. A quadrupole magnet according to claim 2, wherein the two longitudinally active segments of each individual winding coil are arranged on two adjacent sides of the square frame, respectively; In the interval space between two longitudinal acting sections of the same independent winding coil, two other longitudinal acting sections of different independent winding coils are arranged.
4. A quadrupole magnet according to claim 3, The first frame and the second frame are respectively provided with a winding groove, and the outline of each winding groove is matched with the winding path of the transverse bending section and is used for restraining the extending direction of the transverse bending section and expanding the bending space; The winding groove is provided with an opening towards one side of the opposite side frame, and the axis of the opening is parallel to the axial direction of the central particle beam channel and is used for extending the longitudinal acting section from the one side frame to the opposite side frame.
5. A quadrupole magnet according to claim 4, characterized in that, Each edge of the first frame and the second frame is provided with four winding grooves, and each winding groove of the first frame comprises two inner layer winding grooves and two outer layer winding grooves; the inner layer winding grooves are formed in the inner edges of two adjacent edges of the square frame, and the outer layer winding grooves are formed in the outer edges of the other two adjacent edges; Only one transverse bending section of the independent winding coil is wound in each winding groove, so that the inner layer winding groove is isolated from the transverse bending section in the outer layer winding groove.
6. A quadrupole magnet according to claim 5, characterized in that, The winding grooves at the openings are obliquely arranged relative to the edges of the square frames, and the oblique angle is matched with the thickness of the frames and the spacing between the inner layer winding grooves and the outer layer winding grooves; The inclined arrangement enables the inner layer winding groove and the longitudinal acting section extending in the opening of the outer layer winding groove at the edge of the same frame to be in the same plane, and the plane is parallel to the axis of the central particle beam channel.
7. A quadrupole magnet according to claim 5, wherein the frame further comprises a sealing plate covering the open side of the winding slot for closing the slot body and limiting the transverse bending section.
8. A quadrupole magnet according to claim 5, wherein the bend side wall of the winding slot is an arcuate side wall that smoothly transitions the curved path of the transverse bend segment.
9. A quadrupole magnet according to any one of claims 1 to 8, wherein the winding coil is a high temperature superconducting coil.
10. A particle accelerator comprising a quadrupole magnet according to any one of claims 1 to 9 for focusing and directing a particle beam.

Description

Quadrupole magnet and particle accelerator Technical Field The utility model relates to the technical field of particle accelerators, in particular to a quadrupole magnet and a particle accelerator. Background In the medical device field (such as magnetic resonance imaging systems, proton therapy accelerators, etc.), quadrupole magnets are the core components for beam focusing and precise control of particle trajectories. The device has extremely high requirements on the compactness of the magnet, the uniformity of the magnetic field and the operation reliability, and particularly in tumor radiotherapy, the slight deviation of the magnetic field gradient can cause beam positioning errors, so that the treatment effect and the patient safety are directly influenced. However, the coil design of conventional quadrupole magnets faces serious challenges. In the conventional coil winding process, in order to accommodate more turns in a small space, multiple sharp-angle bends (turning bends at the inner ends of the bending sections) are often adopted to achieve a compact layout. However, this design has the following problems: 1. The turn number density is limited, namely, a bending allowance (such as bending radius is more than or equal to 3 times of the thickness of the strip material) is reserved for acute bending, so that the practically available space of the innermost layer of the coil is greatly reduced, and the turn number density is limited. 2. The brittleness risk of the superconducting material is that in the superconducting material, the high-temperature superconducting tape (such as REBCO) is a brittle ceramic, and acute bending can cause internal microcracks, so that critical current density is obviously degraded, and even local fracture failure occurs. Particularly in the field of medical equipment, a high-strength magnetic field (gradient is more than or equal to 100T/m) needs to be realized in a limited space (for example, the aperture of a magnet of a proton treatment rotating frame is less than or equal to 30 cm), but the traditional design is difficult to achieve compactness and high performance due to bending limitation, the magnetic field strength is sacrificed when the number of turns is reduced for reducing the volume, the size of the magnet needs to be enlarged when the number of turns is increased, and the space limitation of the medical equipment cannot be adapted. Current mainstream solutions to the above problems include: And winding the multi-layer thin tape, namely replacing a single thick tape by a plurality of thin superconducting tapes, wherein the bending stress can be partially relieved, but the interlayer contact resistance is increased, so that the current loss is increased. In the flexible substrate technology, a flexible metal substrate is attached to the back of the superconducting tape, and bending toughness can be improved, but extra thickness introduced by the substrate further compresses a winding space, so that the turn number density is reduced. In summary, how to realize high-turn-number-density winding of superconducting coils in a small space and avoid material damage caused by acute-angle bending becomes a key bottleneck of medical-grade quadrupole magnet design. What is needed is a new winding structure that can maximize the utilization of limited space, adapt to the mechanical properties of superconducting materials, and ensure dual improvement of magnetic field gradients and operational reliability. Disclosure of utility model The utility model solves the technical problems that in the existing quadrupole magnet design, the acute angle bending of the coil causes damage of superconducting materials and the utilization rate of winding space is low, and particularly in the miniaturized scene of medical equipment, the high turn number density and the magnetic field uniformity are difficult to be considered, so that the magnetic field gradient is insufficient and the material reliability is poor. (II) technical scheme In order to solve the above technical problems, an embodiment of the present utility model provides a quadrupole magnet, which comprises a first frame, a second frame and four independent winding coils wound between the two frames, The first frame and the second frame are symmetrical closed frames, are arranged in parallel at intervals and are rotationally symmetrical around a particle beam flow channel positioned in the center of the two frames; Each independent winding coil includes: two sections of transverse bending sections respectively extend, wind and are fixed at the corresponding edge parts of the first frame and the second frame; The two longitudinal acting sections are bridged between the transverse bending sections and extend along the axial direction of the central particle beam channel and are used for generating a quadrupole magnetic field; And a spacing space is formed between two longitudinal acting sections of the same independent wind