摘要
为了提高中子产额,法兰克福强中子源采用Mobley型束团压缩器来增强打靶时质子流的密度,其入口处由射频踢波器实现微脉冲的偏转,踢波器由一对电偏转板和串联电感线圈组成谐振腔体。考虑到高频下寄生电容效应、导体腔壁对线圈电感的影响以及涡流效应对线圈交流电阻的影响,对一台模型腔的射频特性进行了理论预测。对腔体内电磁场分布进行了数值模拟,并利用电容微扰法进行了冷模测量。针对谐振频率、品质因数和并联分路阻抗等参数,分析比较了理论计算、数值模拟及冷模测量的结果,总结得出射频踢波器的有效设计方法。
A Mobley type bunch compressor is adopted to enhance proton intensity at the Li target hence neutron flux for the Frankfurt Neutron Source at the Stern-Gerlach-Zentrum（FRANZ）.At first the micro bunches in one proton macro bunch are successively deflected by a RF chopper located at the front focus of the compressor with various angles,whereafter pass through an optimized magnetic bending system in different trajectories,and finally arrive at the end focus of the compressor,i.e.the target,simultaneously.The chopper cavity consists of a pair of opposite plates serving as a bunch deflector,connected with an inductive winding in series to stimulate resonance at 5 MHz.To design such a chopper,a scaled model is constructed to start with.Theoretical analyses of its RF properties are accomplished while considering the parasitic capacitances,the shielding effect of the cavity wall on the winding inductance,and the eddy current effects at high frequency.Meanwhile,the numerical simulations of the model＇s electromagnetic field are carried out with CST Microwave Studio（MWS）.The model is also cold tested using vector network analyzer by means of perturbation capacitor method.The theoretical and simulated results such as the resonant frequency and parallel shunt impedance are compared with the experimental values.An efficient optimizing strategy is accordingly established for the real chopper based on these results.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2011年第2期490-494,共5页
High Power Laser and Particle Beams
关键词
中子源
踢波器
模型腔
寄生电容
涡流效应
分路阻抗
neutron source
bunch chopper
scaled model
parasitic capacitance
eddy current effect
shunt impe-dance
