光学渡越辐射在电子束能谱测量上的应用

THE APPLICATION OF OPTICAL TRANSITION RADIATION IN ELECTRON ENERGY SPECTRUM DIOGNOSIS

论述了用光学渡越辐射对强流短脉冲束团的能谱进行测量的理论和方法。探讨了利用单膜装置、双膜装置或多膜装置产生的光学渡越辐射进行束流能谱测量的方法，并针对２０ＭｅＶ电子感应直线加速器能散为０．５％的电子束能谱测量作了一些计算以得到部分装置的设计参数。计算表明：应用渡越光栅谱仪选择合适的膜片厚度及间距，对于给定的电子能谱，可以得到大的能量接受度和好的能量分辨率。然而，要用大量的膜片是困难的，而且还有许多影响多膜渡越辐射能谱仪的实际问题需要讨论。

The method of measuring the energy spectrum of a high current and short pulse beam using optical transition radiation is presented in the paper. The energy spectrum of charge particle beam can be studied by analyzing the optical spectrum of the optical transition radiation produced by a single foil, a double foil or multi foil setup. And, some calculation are made to let the system be more fit to the electron beam erergy spectrum for 20 MeV linear induction accelerator with energy spread of 0.5 %. Calculation shows that large energy acceptance with good resolution can be achieved for given electron spectrum by proper selection of foil thickness and spacing when using TRG spectrometer. However, it is difficult for a large number of foils to be used. The practical issues, which may affect the performance of the multi foil transition radiation energy spectrometer,is discussed.