30 keV He^(2+)在不同倾斜角度的聚碳酸酯微孔膜中的传输过程  

Transmission of 30-keV He^(2+) ions through polycarbonate nanocapillaries: Dependence on the incident angle

作　　者：牛书通 周旺[1,2] 潘鹏 朱炳辉[1] 宋涵宇 邵剑雄 陈熙萌[1] Niu Shu-Tong;Zhou Wang;Pan Peng;Zhu Bing-Hui;Song Han-Yu;Shao Jian-Xiong;Chen Xi-Meng(School of Nuclear Science and Technology,Lanzhou Universit;The Longrui Technology Company Limited,China National Nuclear Corporatio)

机构地区：[1]兰州大学核科学与技术学院,兰州730000 [2]中国核工业集团有限公司中核龙瑞科技有限公司,嘉峪关735100

出　　处：《物理学报》2018年第17期206-213,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11675067)资助的课题~~

摘　　要：本文测量了30 keV的He^(2+)入射倾斜角度分别为-0.5~?,-1~?,-1.5~?和-2.5~?的聚碳酸酯纳米微孔膜后,出射粒子角度分布、电荷态分布以及相对穿透率随时间的演化.当微孔膜倾斜角度在-0.5~?,-1~?和-1.5~?时,出射的He^(2+)离子始终保持在入射束流方向,出射的He^0原子出射方向由微孔孔道方向逐渐转移到入射束流方向,在实验过程中观测到明显的电荷交换,这一现象与之前发现的导向效应不同,微孔内部沉积的电荷斑和微孔内表面原子的短程集体散射作用,克服入射离子的横向动量,使入射离子在微孔内表面以上以类似镜面掠射的方式出射,并发生时间演化效应,主要传输机制为电荷斑辅助的表面以上的类似镜面掠射行为.而当倾斜角度在-2.5~?时,出射的He^(2+)离子始终保持在入射束流方向,出射的He^0原子始终保持在微孔孔道方向,沉积的电荷斑很难克服入射离子的横向动量,没有时间演化效应,主要传输机制为微孔内表面以下的多次随机非弹性碰撞过程.这一物理图像使中能离子入射不同倾斜角度的微孔膜物理认识更加深入和完整.Nanocapillaries in various materials have received considerable attention due to the rapid growth of the nanotechnology. Recent studies have focused on the transmission of ions through the nanocapillary.The pioneer work, the transmission of 3-keV Ne^7＋ through polyethylene terephthalate nanocapillaries based on guiding effect has been reported by Stolterfoht et al.（2002 Phys. Rev. Lett. 88 133201）, indicating that the selforganized charge patches on the capillary walls, which inhibits close contact between the ions and the inner capillary walls, deflecting the trajectories of ions, and thus the ions transmit along the direction of the capillary axis. For the high-energy region（E/Q 1 MV）, Hasegawa et al.（2011 J. Appl. Phys. 110 044913） measured the outgoing angle and energy distribution of 2 MeV H^＋ ions transmitted through a tapered glass capillary. The results indicated that the main transport mechanism of the MeV ions in a tapered glass capillary is the multiple random inelastic collisions below the surface.In the medium-energy region（E/Q from dozens of kV to hundreds of kV）, Zhou et al.（2016 Acta Phys. Sin. 65103401） measured the transmission features of the 100-keV protons transmitted through a polycarbonate（PC） membrane at a tilt angle of ＋1°, the transmitted particles were located around the direction along the incident beam, not along the capillary axis, the transport mechanism of the 100-keV protons in the nanocapillary is the charge-patch-assisted collective scatterings on the surface. With the nanocapillary membranes at different tilt angles, the transverse momentum of the incident ions are different. What is the transmission mechanism of the ions in nanocapillary membranes at different tilt angels？ In the present study, we measure the time evolution of the angular distribution, charge state distribution and relatively transmission rate of 30-keV He^2＋ ions with 500 p A transmitting through a polycarbonate nanocapillary membrane at different incident angles（-0.5°,-1

关 键 词：倾斜角度 微孔膜 镜面掠射 

分 类 号：O633.14[理学—高分子化学] TB383.2[理学—化学]