涡流对电真空器件内磁分布的影响及抑制方法

短脉冲线圈电流励磁是高频电真空器件中实现超强磁场的重要技术途径之一，此时器件内将不可避免地产生涡流并进一步对内部磁场分布构成影响。针对使用短脉冲磁场时涡流对电真空器件内磁分布的影响进行了研究，分析了线圈电流脉冲宽度、金属电导率和金属厚度等对涡流的影响，结果表明:随着线圈电流脉冲宽度的减小、金属电导率和金属厚度的增加，涡流对内部磁场的影响也随之增加，导致管内空间无法有效励磁。提出了两种抑制涡流影响的措施，包括采用高电阻率导体进行薄层电镀和对管壁金属纵向切槽开缝。计算结果表明，这两种方法能够有效抑制涡流对器件内部磁场分布的影响，具有良好的实用性。

Influence of eddy-current on inside magnetic field distribution in vacuum electronic devices and corresponding suppression methods

Excitation of magnetic field with short pulse current coils is one of the important technological approaches for achieving ultra-strong magnetic field in high frequency vacuum electronic devices, in which eddy-current would be excited at the same time and influence the distribution of magnetic field inside the tube. Impact of eddy-current on the distribution of short pulse magnetic field is studied in this paper, the effects of pulse duration, conductivity and thickness of the metallic structure on eddy-current are analyzed. The results show that the influence of eddy current on the internal magnetic field increases with the decrease of the pulse width of the coil current, the increase of the conductivity and the thickness of the metal, which leads to failure of effective excitation of magnetic field inside the tube. Two methods for suppressing eddy current are proposed including electroplated coating of good conductor on high-resistivity metallic material and longitudinal slotting, the calculation results show that the two methods could effectively depress the influence of eddy-current on the distribution of magnetic field in the device.