摘要
提出一个新颖的射频电子束团序列在偏转或者摇摆磁场中发射的相干同步辐射相干迭加导致辐射增强的理论模型 ,并基此分析和计算了利用BFEL装置的 3 0MeV射频直线加速器产生的电子束团序列发射的相干辐射增强效应 .由讨论可知 ,不同的束团产生的相干同步辐射之间存在相干性源于束团间的相干性 ;这种束团间的相干性引起的辐射增强迭加在单个束团产生的相干辐射功率谱上 ;随着波长的增长 ,这种辐射增强呈现规则的高速振荡效应 ;束团间相干性引起的强度增强近似约为宏脉冲内所含束团数的平方 .最后提出利用所设计的毫米波Michelson干涉仪检测BFEL装置的电子束团序列的相干性的实验设想 .
A novel model for the inter bunch interference in a bunch train is presented where a train of electron bunches passing through a bending or undulator magnetic field is considered as a moving multi slit diffraction array from which multi beams of coherent radiation emitted with definite phase difference. Based on this model,interference among multi beams of coherent synchrotron radiation emitted from consecutive bunches accelerated by a 30 MeV RF Linac at BFEL is analyzed and numerically calculated. From the discussions it is shown that: 1. Rapidly oscillating radiation enhancement due to inter bunch interference is overlapped on the single bunch power spectrum;2. Such radiation enhancement consists of series of spectrum lines corresponding to harmonics of the fundamental of RF Linac;3. Main maximum positions are determined by the “diffraction condition”;4. Intensity enhancement is about as high as the number of bunches in a macropulse;5. The axially measured radiation frequency is lower than the offaxis one. Experimental design to measure interference from separate bunches at the BFEL Linac with the developed mm wave Michelson interferometer is presented.
出处
《高能物理与核物理》
EI
CSCD
北大核心
2001年第5期455-460,共6页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金! (1 98750 66)
高能所所长基金
国家高技术 -激光技术领域资助&&
