A Periodic Permanent Magnet Focusing System Suitable for Ribbon Electron Beam

Abstract

The invention discloses a periodical permanent magnet focusing system suitable for a strip-shaped electron beam. Since the magnetic field direction of any adjacent two pole shoes is opposite, and the magnetic field direction is perpendicular to the strip-shaped surface of the strip-shaped electron beam, at the same time, two sets of stair-shaped sliders The rails are mirrored up and down along the transmission direction with the width of the strip-shaped electron beam, and the pole shoes and magnetic blocks on it are also mirrored. Therefore, the strip-shaped electron beam is focused in the thickness direction so that it no longer spreads along the thickness direction. In addition, by adjusting (transversely moving) the pole pieces clamped by the slide rails, the pole pieces on the upper and lower sets of stair-type slide rails can generate a magnetic field at both ends of the strip-shaped electron beam section, and the magnetic field can affect the width direction of the electron beam. Focusing, by sliding the pole piece, the magnetic field at both ends of the electron beam section can be adjusted, so that the width direction can be properly focused, so that the belt-shaped electron beam can be stably transmitted and achieve a higher flow rate.

Description

technical field [0001] The invention belongs to the technical field of vacuum electronic devices, and more specifically, relates to a vacuum electronic device such as a traveling wave tube, a return wave tube, a klystron, a gyrotron, a free electron laser, an Oro tube, and a terahertz maser. Periodic permanent magnet focusing system for ribbon electron beams. Background technique [0002] Vacuum electronic devices are a kind of power amplifier devices that convert the kinetic energy of high-energy electron beams into electromagnetic microwave energy after the interaction between high-energy electron beams and electromagnetic microwave signals, including traveling wave tubes, klystrons, return wave tubes, gyrotrons, etc. [0003] Conventional vacuum electronic devices mostly use cylindrical electron beams. In order to achieve stable transmission of electron beams, axisymmetric solenoid magnetic fields, periodic permanent magnets, or permanent magnet focusing systems are gener...

AI Technical Summary

Problems solved by technology

like figure 1 As shown, when the traditional solenoid DC magnetic field focuses the ribbon electron beam, it will produce diocotron instability, which will cause the cross-section of the ribbon electron beam to knot, break and filamentize, and then reduce the flow rate of the ribbon electron beam

[0007] The annular periodic permanent magnet (PPM) focusing system suitable for circular electron beams, due to its rotational symmetry, the electron beams will rotate and hit the electron beam channel, reducing the flow rate, and it is not suitable for focusing belt-shaped electron beams.

[0008] When the ribbon-shaped electron beam is transported in the electric vacuum device, the electron beam will disperse without magnetic field focusing, and the DC magnetic field focusing will form diocotron instability. Note rotation, these two focusing methods will cause electron beams to hit the channel wall, resulting in large current loss and low flow rate in the transmission process

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