渡越辐射在强流电子束诊断中的应用

Research of Transition Radiation on Intense Electron Beam Diagnostics

文中描述了渡越辐射用于束流诊断的理论依据 ,介绍了利用渡越辐射对 18MeV ,2 .7kA的强流脉冲电子束进行诊断的实验方案 ,介绍了在强流束测量中遇到的困难和解决方法 .实验中获得了渡越辐射的特征图案 ,并对特征图案进行了分析 ,得到了测量时应该使用偏振片的结论 .据此 ,利用渡越辐射测量了强流脉冲束的剖面、能量、发散角 .并采用渡越辐射与切伦科夫辐射相结合的方法 ,用切伦科夫辐射测量束剖面 ,用渡越辐射测量能量和发散角 ,在同一次实验中获得了强流脉冲束的归一化发射度 .

In this paper, the theoretical background of OTR (abbreviation for Optical Transition Radiation) is stated, the principle of applying OTR to beam diagnostics is described, the schemes of experiments on an electron beam of 18 MeV, 2.7 kA are presented. In intense electron beam diagnostics, there are many difficulties, such as target destruction, X-ray noise, electron-magnetic disturbance, and so on. After overcoming these difficulties, the characteristic pattern of OTR with and without polarizing glass are both obtained. The conclusion that polarizing glass should be used in beam diagnostics is deduced after analyzing the difference between the tow patterns. With OTR method, the beam profile, energy, divergence are measured. OTR and Cerenkov radiation are used simultaneously to measure the normalized beam emittance. In this experiment, OTR is used to measure the energy and divergence, and Cerenkov radiation is used to measure the profile.