Beam axial track adjustment device for cyclotron

Abstract

The invention discloses a beam axial track adjustment device for a cyclotron. The device comprises a first electrostatic deflection apparatus and a second electrostatic deflection apparatus, and the first and second electrostatic deflection apparatuses have the same structure, and respectively comprise an upper electrode and a lower electrode, which are vertically symmetric relative to the centralplane of the cyclotron. The upper electrode of the first electrostatic deflection apparatus is disposed on the upper surface of a first peak zone magnetic pole in the cyclotron, and the lower electrode of the first electrostatic deflection apparatus is disposed on the lower surface of the first peak zone magnetic pole in the cyclotron. The upper electrode of the second electrostatic deflection apparatus is disposed on the upper surface of a third peak zone magnetic pole in the cyclotron, and the lower electrode of the second electrostatic deflection apparatus is disposed on the lower surfaceof the third peak zone magnetic pole in the cyclotron. The device can independently adjust the voltage differences between the upper and lower electrodes of the first and second electrostatic deflection apparatuses, carries out the axial track adjustment of a particle beam, and enables a beam deflecting from the central plane to return to the central plane.

Description

technical field [0001] The invention belongs to the field of cyclotrons, and more particularly relates to a beam axial orbit adjustment device of a cyclotron. Background technique [0002] Precise and rapid radiotherapy is the development direction of particle beam radiotherapy. Cyclotron-based proton radiotherapy devices have occupied more markets due to their advantages in size and cost. In a cyclotron, the beam may have a certain initial axial position and momentum deviation due to the external source injection or the installation of the internal ion source. If it is not effectively compensated, the beam will move tens of circles or even several circles later. loss. Due to the narrow space between the main magnets of the cyclotron, when the high-energy beam has a small axial position deviation in the cyclotron, it will be lost due to axial oscillation, and the secondary particles produced by the reaction between the proton beam and the surface material will not only Red...

AI Technical Summary

Problems solved by technology

In a cyclotron, the beam may have a certain initial axial position and momentum deviation due to the external source injection or the installation of the internal ion source. If it is not effectively compensated, the beam will move tens of circles or even several circles later. loss

Due to the narrow space between the main magnets of the cyclotron, when the high-energy beam has a small axial position deviation in the cyclotron, it will be lost due to axial oscillation, and the secondary particles produced by the reaction between the proton beam and the surface material will not only Decreases the quality of the vacuum inside the accelerator, and will produce neutrons causing radiation and surface activation problems

Due to the trend of miniaturization of accelerators, more cyclotrons adopt superconducting coil technology. The secondary particles produced by the reaction of high-energy proton beams and materials may also penetrate the magnet and bombard the superconducting coil, causing the local temperature of the coil to be too high, causing the coil to quench. risk

[0003] This kind of beam axial oscillation is likely to be caused or strengthened by the installation deviation of the main coil of the cyclotron and the installation deviation of the ion source. The intensity of the extracted beam is extremely low, or a large loss of high-energy beam is caused due to the limitation of the extraction aperture during extraction, causing risks such as quenching

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