Structure design for electron beam controlling in microwave tube with carbon nanotube cathode  

碳纳米管阴极微波管的电子束聚束系统设计(英文)

作　　者：赵红平[1] 雷威[1] 张晓兵[1] 顾伟[1] 李晓华[1] 

机构地区：[1]东南大学电子工程系,南京210096

出　　处：《Journal of Southeast University(English Edition)》2006年第2期159-163,共5页东南大学学报（英文版）

基　　金：TheNationalBasicResearchProgramofChina(973Program)(No.2003CB314706).

摘　　要：To control the electron beam emitted from the carbon nanotube （CNT） cathode, four different electron chunnels are designed. A common basic structure used in the simulation is an insulating chunnel. When primary electrons hit the surface of the chunnel, secondary electrons are generated, which make the electron distribution at the exit hole of the chunnel more uniform. By analyzing and comparing the state of electrons emitted from the exit of chunnel among the four structures, an optimal structure is obtained. In the optimized structure, the electron distribution at the exit hole of the chunnel is more uniform and the electron beam is rather slim. Furthermore, by adding a magnetic field along the slow wave line, the electron beam can be constrained. In the optimized structure, a very small magnetic field is needed to make most of electrons pass through the slow wave line.为了控制碳纳米管阴极发射电子束的形状,设计了4种电子通道来控制电子束轨迹.在设计结构中,其基本结构是一倒置的内壁涂有绝缘材料的漏斗状通道.当初始电子碰撞绝缘壁时,会产生二次电子,而二次电子能改善电子在通道出口处的电子能量分布的均匀性.通过分析和比较电子在通道出口处的状态,得到了一种理想的通道结构.在该结构中,电子在通道出口处的分布更加均匀,电子束的束径较小.而且通过在慢波线外部加磁场的方法来控制电子束在慢波线中的扩散,所加的磁场越大,电子在慢波线中的通过率则越大.通过分析4种不同的结构,在所得到的一种理想的通道结构中,需要较小的磁场就能使得电子在慢波线中的通过率较高.

关 键 词：carbon nanotube electron chunnel transverse velocity of electrons 

分 类 号：TN124[电子电信—物理电子学]