非均匀磁场约束条件下的电子束空气等离子体特性  

Properties of electron-beam produced air plasma in nonuniform magnetic field

作　　者：栾希亭[1] 邓永锋[2] 谭畅[2] 韩先伟[2] 毛根旺[1] 

机构地区：[1]西北工业大学航天学院,西安710072 [2]陕西动力机械设计研究所,西安710100

出　　处：《强激光与粒子束》2010年第9期2032-2036,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(10905044;50911120076)

摘　　要：为了揭示大气环境电子束等离子体的性质,基于蒙特卡罗程序包Geant4建立了一个包含电离、激发以及轫致辐射等物理过程的计算模型,用于模拟非均匀磁场约束条件下高能强流稳态电子束的输运特性、以及大气环境等离子体的性质。结果表明:非均匀磁场可以有效控制电子束在空气中的输运轨迹,显著降低电子束的发散;随着电子束在空气中行程的增加,电子束能谱开始展宽并向低能区移动;输运装置出口能量损失比电子束射程末端高2个量级,且随着电子束输运距离的增加,等离子体密度降低;等离子体密度的高低与电子束能量直接相关。The atmospheric electron-beam produced air plasma attracts intensive attentions recently. Based on a Monte Carlo toolkit named Geant4,a model including complete physics processes is established to simulate the passage of the electron beam in air in nonuniform magnetic field. By using the model,the characteristics of the electron-beam produced air plasma are simulated. The results indicate that,the nonuniform magnetic field is effective controlling the trajectories of electron beams and can reduce the beam divergence obviously. The energy spectrum becomes wider with the increase of beam penetration depth and secondary electrons play a significant role in low energy range. Moreover,the magnitude of energy deposition at the outlet of the transportation section is two orders higher than that at the beam end,and the highest plasma density appears at the outlet. Thus,a conclusion is drawn that the plasma density is closely related to the beam energy.

关 键 词：电子束 大气环境 等离子体 非均匀磁场 蒙特卡罗 

分 类 号：O532.26[理学—等离子体物理]