低能电子穿越玻璃直管时倾角依赖的输运动力学  

Dynamics of low energy electrons transmitting through straight glass capillary:Tilt angle dependence

作　　者：李鹏飞[1] 袁华 程紫东 钱立冰 刘中林 靳博[1] 哈帅 张浩文 万城亮[1] 崔莹[1] 马越 杨治虎[4] 路迪 Reinhold Schuch 黎明[7] 张红强[1,8] 陈熙萌[1] Li Peng-Fei;Yuan Hua;Cheng Zi-Dong;Qian Li-Bing;Liu Zhong-Lin;Jin Bo;Ha Shuai;Zhang Hao-Wen;Wan Cheng-Liang;Cui Ying;Ma Yue;Yang Zhi-Hu;Lu Di;Reinhold Schuch;Li Ming;Zhang Hong-Qiang;Chen Xi-Meng(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;School of Nuclear Technology and Chemistry&Biology,Hubei University of Science and Technology,Xianning 437100,China;RIKEN Nishina Center,RIKEN,Wako,351-0198,Japan;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Department of Physics,University of Gothenburg,SE-41296 Gothenburg,Sweden;Physics Department,Stockholm University,SE-10691 Stockholm,Sweden;Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang 621900,China;Frontiers Science Center for Rare Isotopes,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000 [2]湖北科技学院核技术与化学生物学院,咸宁437100 [3]RIKEN Nishina Center,RIKEN,Wako,351-0198,Japan [4]中国科学院近代物理研究所,兰州730000 [5]Department of Physics,University of Gothenburg,SE-41296 Gothenburg,Sweden [6]Physics Department,Stockholm University,SE-10691 Stockholm,Sweden [7]中国工程物理研究院电子工程研究所,绵阳621900 [8]兰州大学稀有同位素前沿科学中心,兰州730000

出　　处：《物理学报》2022年第8期106-113,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:U1732269,11805169);中央高校基本科研业务费(批准号:lzujbky-2021-sp41);瑞典科研与教育国际合作基金(STINT)(批准号:IB2018-8071)资助的课题~~。

摘　　要：采用900 e V能量的电子对直玻璃管进行了穿透实验,测量了玻璃管在倾角为–0.15°,–0.4°和–1.15°时充电过程角分布的时间演化,以及平衡态下出射电子能谱.发现穿透率随时间先下降后上升最后趋于平稳,下降的时间随倾角的增大而减小.当倾角为–0.4°和–1.15°时,电子穿透率下降到最低点时几乎看不到穿透电子(穿透率小于3‰),这种穿透率最低点状态保持时间随倾角增大而增大.穿透电子的角分布中心随着时间变化.在平稳状态时,发现穿透电子的能量损失随倾角增大而增大.采用蒙特卡罗方法模拟了电子经过管壁不同次数反射后的能谱,与测量能谱进行对比,发现–0.15°,–0.4°和–1.15°倾角下,穿透电子分别经历了管壁的一次、两次和三次与表面的反射过程.基于此,本文对电子穿越玻璃管的充电过程动力学给出了物理解释.实验结果和理论分析表明,在小倾角下玻璃管内能形成宏观负电荷累积,排斥后续电子形成反射,增加电子出射概率,这对应用绝缘体微结构,例如玻璃锥管产生稳定的电子微束具有重要的参考意义.It is a hot topic that using glass capillary to focus and shape the charged particle beam,for it is inexpensive and simple.There are the cases that single glass capillaries are used to make the microbeam of the positive ions.When it comes to electrons,their transmitting through insulating capillaries is complex and the attempt to use the glass capillary to produce electron beams in the size of micrometer needs further exploring.In this paper,the charging-up process of the 900-eV electrons transmitting through a glass capillary with the grounded conductive-coated outer surface is reported.Two-dimensional angular distributions of the transmitted electrons and their time evolutions are measured for the cases of various tilt angles of glass tube.It is found that there are a considerable number of transmitted electrons at the tilt angle exceeding the geometrical opening angle(1°)of the glass tube.The intensity of transmitted electrons for large tilt angle(i.e.–1.15°)can be considered as first falling to zero,then keeping zero for a long time,finally rising to a certain stable value.Correspondingly,the angular distribution center experiences moving towards negative-positive-negativesettled.The energy losses are measured for various tilt angles.The larger the tilt angles,the larger the energy loss of transmitted electrons is.To better understand the physics behind the observed phenomena,the simulations of the energy loss for transmitted electrons at various tilt angles are performed by the Monte Carlo method.The comparation between the simulated energy losses and the measured energy losses shows that the experimental results are well explained by multiple deflections from the wall.

关 键 词：电子 能量损失 充电过程 玻璃毛细管 

分 类 号：O572.322[理学—粒子物理与原子核物理]