强流电子束入射弯曲宏观石英管的导向效应研究

Guiding Effect of Bended Macroscopic Quartz Tube for High Current Electron Beam

研究了强流(～129 nA)、高能(1 500～1 900 eV)电子束在大角度(9°)弯曲宏观石英管中的导向效应。实验分别测量了入射流强及能量对出射电子角分布值(FWHM)和传输效率的影响。实验观察到出射电子角分布FWHM随着入射电子流强和入射电子能量增加变化均不明显;发现电子传输效率随入射流强增加而增加,但随入射能量增加而减小,这与高电荷态离子导向中离子传输效率随入射能量增加而增加的现象相反。分析发现,与高电荷态离子导向机制不同,电子束导向并非是由电子在石英管内壁的自组织充电过程引起的,而是入射电子与管内壁弹性和非弹性散射碰撞共同作用的结果。

By using an incident electron beam with the high current and high energy, the guiding effect of the bended macroscopic quartz tube for the electron beam has been investigated. The angular distributions of outgoing electrons depending on the current and energy of incident electrons were measured. The de- pendences of electron transmitted fraction on energy and current of incident electrons are also shown. As the incident electron energy increasing, the electron transmitted fraction increases, but it decreases while the incident electron current increasing. The results have been compared with the present data. This work presents, the process of guiding electrons is essentially different from that of guiding highly charged ions, the guiding electron beam was caused by both elastic and inelastic collisions between electrons and inner walls of quartz tube, rather than self-organized charging effect on the surface of inner wall of quartz tube.