Compact medium-energy negative-hydrogen high-current isochronous cyclotron straight-side fan main magnet

Abstract

The invention discloses a compact medium-energy negative-hydrogen high-current isochronous cyclotron straight-side fan main magnet which is characterized in that the intersection point of two straightsides of each straight-side fan-shaped magnetic pole does not radially coincide with the central point of a cover plate, and the intersection point is positioned on the circumference of the central area of the cover plate; the circle center of the arc at the tail part of each straight-side fan-shaped magnetic pole is strictly overlapped with the center of the cover plate, and the radius at the fan-shaped magnetic pole side of each straight-side fan-shaped magnetic pole is smaller than the curvature radius of the arc at the tail part of the fan-shaped magnetic pole; the reduction of the large-radius angular width of a panel is enough larger than the arc length of the magnetic pole of the main magnet increased at the large radius, so that the total angular width of the magnetic pole at thelarge radius and the panel is reduced compared with an existing structure, namely, alpha is reduced, and accordingly, the modulation degree and the focusing force are increased; alpha is the proportion of the fan-shaped magnetic pole of the magnet and the panel on the central plane and in the circumferential direction. By adjusting the proportional relation between the radius of the fan-shaped magnetic pole and the curvature radius of the arc at the tail of the fan-shaped magnetic pole and combining the modes of adjusting the magnetic pole panel outline and the like, magnetic field variable-gradient focusing is convenient to introduce.

Description

technical field [0001] The invention belongs to the technical field of high-current proton cyclotrons, and in particular relates to a main magnet of a compact medium-energy negative hydrogen high-current isochronous cyclotron. Background technique [0002] A cyclotron is a device that uses a magnetic field and an electric field to make charged particles perform cyclotron motion, and is repeatedly accelerated by a high-frequency electric field during the motion. It is an important tool for nuclear physics and nuclear technology application research. The medium energy negative hydrogen strong current isochronous cyclotron means that the accelerated ion species is negative hydrogen (H - ), the final energy of the accelerated ions reaches above 100MeV (including 100MeV), and the intensity of the accelerated and extracted beam reaches above 200μA. The medium-energy high-current proton cyclotron can produce high-current proton beams, target high-flux neutrons and radioactive nucl...

AI Technical Summary

Problems solved by technology

This will bring about a series of problems including increased tangential force and deformation of the insert, insufficient high-frequency acceleration clearance at large radii, etc., which will eventually lead to increased beam loss and limited beam intensity

[0007] 3) The existing compact isochronous cyclotron straight-side fan main magnet technology has the problem of insufficient focusing force, which cannot guarantee the axial focusing force required to accelerate negative hydrogen to ≥100MeV energy; it is necessary to use a spiral fan-shaped main magnet or separate Fan-shaped main magnet, but the former will lead to a significant increase in the design risk and difficulty of the high-frequency acceleration system and beam diagnosis system, and the latter will lead to a substantial increase in the overall scale and cost of the accelerator

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