电子能量对收集极中电子束能量沉积的影响

Influence of kinetic energy on energy deposition of incident electron beams in collectors

理论分析了收集极中运动电子的失能机制和电子能量对电子束能量沉积的影响,用蒙特卡罗方法计算了不同能量下入射电子的能量沉积分布,分析了电子能量对电子束在收集极中能量沉积的影响,并据此提出了提高收集极耐电子束轰击能力的两种途径。结果表明:激发和电离是收集极中入射电子的主要失能机制;电子的能量越高,在材料中的穿透能力越强,收集极中被收集电子束的最大能量沉积密度越低。综合考虑束流密度分布对能量沉积的影响,可通过两种途径来提高收集极耐电子束轰击的能力:一是通过结构设计增大电子束的收集面积,减小收集极上被收集电子束的束流密度;二是设计高阻抗器件,增大被收集电子束的电子能量,减小收集极上被收集电子束的束流密度。

The energy loss mechanism and the influence of the kinetic energy on the energy deposition of incident electrons in collectors were analyzed theoretically.Using Monte Carlo method,the energy deposition in collectors of electron beams with different kinetic energies was calculated.The influence of kinetic energy on the energy deposition was analyzed,and two ways were proposed to improve the resistance of collectors to electron beam impact.It was found that excitation and ionization was the major mechanism leading to electrons losing energy.Electrons with higher kinetic energy penetrated further in the collector,but the maximum energy density deposited was lower.Considering the influence of beam distribution on the energy deposition,two ways were put forward to improve the collectors:one was to enlarge the collecting area through structure optimization,and the other was to design HPM generators with higher resistance.