电子束辐射下聚四氟乙烯的电荷输运特性与机理研究

项目名称： 电子束辐射下聚四氟乙烯的电荷输运特性与机理研究

项目编号： No.11275146

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 李盛涛

作者单位： 西安交通大学

项目金额： 90万元

中文摘要： 空间中电子束或离子束与航天器介质材料相互作用时，会造成介质中的电荷捕获、电离、激发等物理过程,进而造成介质的深层充放电现象，极大地影响着航天器的安全运行和寿命。介质的电荷输运特性决定着电子束辐射下介质的深层电荷沉积和消散等充放电物理过程，然而航天领域广泛应用的聚四氟乙烯的电荷输运特性和机制尚不完全清楚。本项目围绕电子束辐射下介质充放电物理过程，研究温度场、电场和电荷浓度梯度场耦合作用下聚四氟乙烯的电荷输运特性和机制。采用龙格-库塔间断伽辽金方法分析介质的表面电位衰减曲线，提取其电导特性；采用空间电荷测量方法、热刺激电流和介电谱等研究材料的陷阱分布；结合双极性电荷输运模型（BCT）研究电荷入陷、出陷机理和电子空穴对的产生与复合机制。进而考虑电子辐射下介质中的电荷分布与能量沉积，采用BCT模型弄清电子束辐射下介质的深层充放电物理过程，为介质深层充放电新防护理论和方法提供理论基础和实验依据。

中文关键词： 电子束辐射；聚四氟乙烯；电荷输运；深层带电；陷阱特性

英文摘要： The interaction of charged particles, such as electrons, protons, and ions, and insulation material on spacecraft will cause charge deposition, ionization, excitation, and coulomb collision in the material. Irradiation induced deep dielectric charging/discharging (DDCD) of the insulation material in space environment extremely affects the safe operation and life time of spacecraft. The charge transport properties of insulating material determines the DDCD physical processes, including charge deposition and dispersion. Nevertheless, the charge transport properties of Polytetrafluoroethylene (PTFE) which is widely used in space field, such as conduction mechanism, charge injection from electrode to insulating material, and the formation and transportation of charge packets, are not very clear until now. This project will investigate the charge transport properties and mechanisms of PTFE under various temperatures, various electric fields and various charge concentration gradients. We will study the surface potential decay curves by Runge-Kutta Discontinuous Galerkin method (RKDG) and Boundary Element method (BEM) to derive the conduction properties of the material. The trap energy and density of the material will be revealed by dielectric space charge mapping techniques (Pulsed Electro-Acoustic), thermal simulated

英文关键词： Electron beam irradiation；PTFE；charge transport；deep dielectric charging；trap charecteristics