CN218338829U

CN218338829U - Medical accelerator beam centering and collimating system based on magnetizing magnet

Info

Publication number: CN218338829U
Application number: CN202221812488.4U
Authority: CN
Inventors: 王传璟; 韩运生; 裘家琪; 王健; 李磊; 王楠
Original assignee: Beijing Huaqing Jiagaoneng Electronic Technology Co ltd
Current assignee: Beijing Huaqing Jiagaoneng Electronic Technology Co ltd
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2023-01-20
Anticipated expiration: 2032-07-13

Abstract

The utility model relates to a beam centering and collimating system of a medical accelerator based on magnetizing magnets, which comprises a linear accelerator and two groups of magnet groups; the magnet group surrounds the linear accelerator; wherein, each group of magnet group comprises four magnetizing magnets. Compared with a mechanical alignment method and a device, the utility model has the advantages of no mechanical movement in the adjustment process, high adjustment speed and convenient operation; compared with electromagnet collimation and devices, only the exciting current needs to be adjusted in the adjusting process, stable control current does not need to be provided after the adjustment is completed, an additional feedback system is not needed, and the stability is higher.

Description

Medical accelerator beam centering and collimating system based on magnetizing magnet

Technical Field

The utility model relates to a medical magnetron, concretely relates to medical accelerator beam centering collimation system based on magnet magnetizes.

Background

Cancer has become one of the main causes threatening the health of people in modern society. Current cancer treatment modalities are surgical ablation, radiation therapy and chemotherapy, with more than half of the patients receiving radiation therapy as the primary or secondary treatment modality.

Compared with an isotope radioactive source, the linear accelerator has a compact structure, and the generated rays can be used immediately after stopping, so that the linear accelerator is gradually the main equipment for medical radiotherapy. The medical linear accelerator accelerates the low-energy electron beam generated by the electron gun to the designed energy value, and directly leads out the electron beam for irradiation or targets to generate X rays for irradiation. In X-ray radiotherapy, the position and angle of the electron beam target can affect the symmetry and uniformity of the dose in the therapeutic field, thereby affecting the final therapeutic effect.

The current adjusting method for beam alignment collimation includes mechanical collimation and electromagnet collimation. Due to the relatively complex structure of the medical accelerator and the treatment head, mechanical alignment is time-consuming and laborious, takes time, usually up to several days, and requires re-alignment after each mechanical movement (due to maintenance and the like). The collimation of the electromagnet requires that the working current stability is good, otherwise, the current fluctuation can cause dose distortion, and certain disturbance can exist on the dose uniformity due to strong electromagnetic interference of the working environment. To reduce the effect of this part, an additional feedback system is required.

SUMMERY OF THE UTILITY MODEL

To the problem that above conventional scheme exists, the utility model provides a medical accelerator beam centering collimation system based on magnet magnetizes. The electromagnet is replaced by a ferromagnetic core with a magnetic memory function, the size of the magnetic field can be changed by changing the size of the exciting current in the beam centering adjustment process, and the magnetic field can not be changed for a long time due to the magnetic memory property of the magnetic core after the collimation is finished, so that the stability of the beam centering collimation and the X-ray dose uniformity generated by targeting is ensured.

The medical accelerator beam centering and collimating system based on the magnetizing magnet comprises a linear accelerator and two groups of magnet groups; the magnet group surrounds the linear accelerator;

wherein, each group of magnet group comprises four magnetizing magnets.

Wherein the magnetic core is a ferromagnetic core.

Wherein, the magnetic core of the magnetizing magnet is cylindrical. The magnetic core is cylindrical, and a magnetic field parallel to the axis of the cylindrical magnetic core can be formed on the longitudinal symmetry plane.

Wherein, the magnetic core is wound with a coil. A ferromagnetic core having a magnetic memory function is magnetized using a coil.

Wherein, the two groups of magnet groups are not contacted. The two groups of magnet groups are at a certain distance, so that the position and the angle of electron beam targeting can be adjusted simultaneously, and the dose symmetry and the uniformity required by relevant regulations of medical radiation equipment are met.

Wherein, two sets of magnet groups are installed in parallel. When two magnetizing magnets with the same polarity are placed in parallel, a magnetic field with certain flatness can be formed in the central area, and the magnetic field is equivalent to a dipolar magnet.

Wherein the magnet group horizontally surrounds the linear accelerator.

Compared with a mechanical alignment method and a device, the beam centering and aligning system of the medical accelerator based on the magnetizing magnet has the advantages that no mechanical movement is caused in the adjusting process, the adjusting speed is high, and the operation is convenient; compared with electromagnet collimation and devices, only the exciting current needs to be adjusted in the adjusting process, stable control current does not need to be provided after the adjustment is completed, an additional feedback system is not needed, and the stability is higher.

Drawings

FIG. 1 is a schematic view of a magnetizing magnet;

FIG. 2 is a schematic diagram of the magnetic field configuration of the magnet assembly;

fig. 3 is a schematic structural diagram of a beam centering and collimating system of a medical accelerator based on a magnetizing magnet.

Detailed Description

The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

Examples

The embodiment provides a beam centering and collimating system of a medical accelerator based on a magnetizing magnet; comprises a linear accelerator and two groups of magnet groups; the magnet group surrounds the linear accelerator;

wherein, each group of magnet group comprises four magnetizing magnets.

The utility model discloses use the coil to magnetize to ferromagnetic core that has the magnetism memory function, as shown in figure 1. When exciting current I is introduced into the coil, the magnetic core can be magnetized. Due to the magnetic memory property of the magnetic core material, the magnetic core can still retain magnetism when the exciting current I is cut off after the magnetizing is finished, and the magnetic field has stability.

If the magnetic core is cylindrical, a magnetic field parallel to the axis of the cylindrical magnetic core can be formed on the longitudinal symmetry plane.

When two magnetizing magnets with the same polarity are placed in parallel, a magnetic field with certain flatness can be formed in the central area, and the magnetic field is equivalent to a dipolar magnet. When two groups of dipolar magnets and four magnetizing magnets are arranged as shown in figure 2, the magnet group formed by the four magnetizing magnets can simultaneously adjust the magnetic fields in the x direction and the y direction; a magnetic field with certain flatness can be formed at the central point and the area near the central point, the magnetic field has components in the x direction and the y direction, respectively B _x And B _y And the deflection device is used for deflecting the beam in the transverse direction.

Two sets of magnet sets, namely magnet set a and magnet set B, can be assembled on the linear accelerating tube in the medical accelerator system, as shown in fig. 3. The 2 groups of magnet groups are at a certain distance, so that the position and the angle of electron beam targeting can be adjusted simultaneously, and the dose symmetry and the uniformity required by relevant regulations of medical radiation equipment are met. Compared with a mechanical collimation method and device, the beam centering collimation method and device have the advantages that no mechanical movement is caused in the adjustment process, the adjustment speed is high, and the operation is convenient and fast; compared with electromagnet collimation and devices, only the exciting current needs to be adjusted in the adjusting process, stable control current does not need to be provided after the adjustment is completed, an additional feedback system is not needed, and the stability is higher.

Although the invention has been described in detail in the foregoing by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that certain modifications and improvements may be made thereto based on the invention. Therefore, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A beam centering and collimating system of a medical accelerator based on magnetizing magnets is characterized by comprising a linear accelerator and two groups of magnet groups; the magnet group surrounds the linear accelerator;

wherein, each group of magnet group comprises four magnetizing magnets.

2. The beam centering and collimating system of a medical accelerator as claimed in claim 1, wherein the core of the magnetizing magnet is cylindrical.

3. The beam centering collimation system as recited in claim 2, wherein the magnetic core is a ferromagnetic core.

4. The beam centering and collimating system of a medical accelerator as claimed in claim 2 or 3, wherein the magnetic core is wound with a coil.

5. The beam centering and collimating system of a medical accelerator according to claim 1, wherein the two sets of magnets are not in contact with each other.

6. The beam centering and collimating system of a medical accelerator as claimed in claim 5, wherein the two sets of magnets are mounted in parallel.

7. The beam centering and collimating system of claim 1, wherein said magnet assembly horizontally surrounds said linear accelerator.