太赫兹频段电子光学系统的研究与设计
发布时间：2018-08-30 08:31
【摘要】：随着对电磁波研究的不断加深,科学家们发现在毫米波段和红外波段之间还存在一段具有很高科学研究价值的电磁 空白‖区域——THz(Terahertz)波。太赫兹波是指频率范围在0.1T-10T(波长范围为3000-30μm)的电磁波(1THz=1012Hz)。THz波在电磁波的频谱范围内占有非常特殊的位置,其还未被全面开发出来的主要原因:一是技术,特别是加工技术上的限制,二是THz源还没得到很好的解决。本论文主要是针对THz源中的电子光学系统进行研究,并设计适用于THz频段的低电压,结构紧凑的电子光学系统。论文采用柱状Pierce结构的电子枪,通过电子注在系统中的受力、场分析和电子注的运动轨迹方程来研究和设计合适的电子枪结构。本文对多维和一维空间电荷限制流进行比较,并用CST软件对阴阳极之间的电压U、阴阳极之间的间距d、阴极发射面半径R和不同的比例系数K(K=R/d)进行了研究。选取二维与一维空间电荷限制流误差较小的一些结构参量作为电子枪结构的初始参量,得到电子枪的主要参量:阴阳极间距d=3mm,K=0.25,rm≈0.05mm。为了得到层流性和流通性较好的电子束,本论文探索了两种不同结构的磁路结构,一种是螺旋管线圈结构磁路,另一种是特殊结构的永磁磁路。通过FEMM和CST软件,分别对它们进行建模和仿真,分析了螺旋管线圈的参数和永磁结构的参数对磁场的影响,经过一系列的优化仿真,得到它们的最优参数。在上述磁场作用下,当电压为8.5kV、阴极发射电流密度J5A/cm2时,用CST软件对电子注的流通性进行优化分析,得到螺旋管磁场结构中电子枪的优化结果:流通率ηα=93.7%,J=3.47A/cm2,J1=138.8A/cm2,压缩比M2≈40,导流系数P=0.0281μP;永磁结构中电子枪的优化结果:流通率ηα=97.23%,J=2.1A/cm2,J1=111.3A/cm2,压缩比M2≈53,导流系数P=0.0288μP。
[Abstract]:With the deepening of the study of electromagnetic waves, scientists have found that there is a high scientific value between the millimeter band and the infrared band in the electromagnetic field, the THz (Terahertz) wave. Terahertz wave is a very special position of electromagnetic wave (1THz=1012Hz). THz wave in 0.1T-10T (wavelength range 3000-30 渭 m), which has not been fully developed. First, the limitation of technology, especially processing technology, is one of the main reasons why terahertz wave is not fully developed. Second, the THz source has not been well resolved. This paper mainly focuses on the research of THz source electron optical system and designs a low voltage compact electronic optical system suitable for THz frequency band. In this paper, the electron gun with columnar Pierce structure is used to study and design the appropriate electron gun structure through the force of electron beam in the system, the field analysis and the motion trajectory equation of electron beam. In this paper, the multi-dimensional and one-dimensional space charge limiting currents are compared. The voltage between cathode and anode, the distance between cathode and cathode D, the radius of cathode emission surface R and the ratio coefficient K (K=R/d) are studied by CST software. Two dimensional and one dimensional space charge limiting current parameters are selected as the initial parameters of the electron gun structure. The main parameters of the electron gun are as follows: the distance between cathode and cathode is 3 mm ~ 0. 25 mm km 鈮，
本文编号：2212540
[Abstract]:With the deepening of the study of electromagnetic waves, scientists have found that there is a high scientific value between the millimeter band and the infrared band in the electromagnetic field, the THz (Terahertz) wave. Terahertz wave is a very special position of electromagnetic wave (1THz=1012Hz). THz wave in 0.1T-10T (wavelength range 3000-30 渭 m), which has not been fully developed. First, the limitation of technology, especially processing technology, is one of the main reasons why terahertz wave is not fully developed. Second, the THz source has not been well resolved. This paper mainly focuses on the research of THz source electron optical system and designs a low voltage compact electronic optical system suitable for THz frequency band. In this paper, the electron gun with columnar Pierce structure is used to study and design the appropriate electron gun structure through the force of electron beam in the system, the field analysis and the motion trajectory equation of electron beam. In this paper, the multi-dimensional and one-dimensional space charge limiting currents are compared. The voltage between cathode and anode, the distance between cathode and cathode D, the radius of cathode emission surface R and the ratio coefficient K (K=R/d) are studied by CST software. Two dimensional and one dimensional space charge limiting current parameters are selected as the initial parameters of the electron gun structure. The main parameters of the electron gun are as follows: the distance between cathode and cathode is 3 mm ~ 0. 25 mm km 鈮，
本文编号：2212540
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