预群聚电子束团辐射特性

研究了预群聚电子束团沿周期性理想金属光栅表面平行移动时产生的史密斯-帕塞尔辐射(SPR).详细分析了电子束团能量、束团群聚长度、具有不同电流密度分布的电子束团以及光栅结构对辐射特性的影响,同时研究了多个群聚束团的辐射.分析发现,电子束团能量增加、束团群聚尺寸变小以及光栅周期变短,辐射能量角分布峰值所对应的频率明显向高频方向移动;光栅周期与电子束团参量相同的条件下,三角形光栅辐射能量角分布峰值所对应的频率明显高于正弦光栅;群聚束团尺寸越小辐射能量越大,并且束团的纵向群聚长度对辐射能量与辐射频率起主要作用.研究结果表明,通过合理选择光栅尺寸与束团参量,可获得工作频率锁定的太赫兹(THz)波段辐射.

Smith-Purcell Radiation from Prebunched Electron Bunches

Smith-Purcell radiation(SPR) from prebunched electron bunches moving in parallel with the surface of periodic ideal metal grating is analyzed.The influence on SPR by the energy,length,and current density distribution of electron bunches and grating structure is analyzed in detail.The radiation of multi-prebunched electron bunches is also studied.With the increase of electron bunches energy and decreases of prebunched electron bunches size and grating period,the corresponding frequency of the peak of the angular distribution of radiative energy becomes higher.For the same grating period and electron bunches parameters,triangle grating produces a higher corresponding frequency than sinusoidal grating.The less electron bunches size is,the larger the radiative energy is.The radiative energy and frequency are mainly dominated by the longitudinal length of electron bunches.Terahertz radiation will be obtained with reasonable parameters for bunches and grating.