静电加速管中强流空间电荷效应的研究

 对一种工业用大功率电子加速器(450kW)的加速管中的空间电荷效应作了5点假设,建立了物理模型。对模型的束内外径向电位分布、空间电荷对轴上电位的影响,以及空间电荷力对束流传输的影响等进行了理论分析,得到了束内径向电位分布。结果表明：束流内部径向电位沿径向均呈抛物线变化,并在轴上达到最小值;而空间电荷产生的束内电场与半径呈线性变化;空间电荷不仅会引起轴上电位的跌落,而且对束流有发散作用,特别是在电子速度较低时更为明显。在考虑了空间电荷效应后,强流静电加速管的电场设计关键在加速管的前端,与弱流加速管相比,强流加速管的电场变化要大得多。

Study on space-charge effects of intense current in electrostatic accelerating tube

This paper studies the space-charge effect of intense current in electrostatic accelerating tube based on 5 hypothese, including the potential distribution in and out beam, the impact on the axial potential by space charge and the transport of intense current. The results show that the radial potential curves of inner beam are all parabolas and they reach the minimum on the axis. The relationship between space-charge fields and the beam radius is linear.The space-charge causes not only the decrease of axial potential, but also the divergency of beam, especially at the low speed of electron. One of the key points lies in the design of the front fields of electrostatic accelerating tube when the space-charge effects are considered, and the fields change of high current tube is greater than that of low current tube.