低能段的光学渡越辐射

光学渡越辐射（ＯＴＲ）作为中高能段束流诊断方法，已被广泛地研究。低能ＯＴＲ的分布不像高能时那样集中于反射方向附近一个极小的角度内，而是在沿反射方向的很大的立体角内分布，且斜入射时强度分布极不对称。这使低能ＯＴＲ 的实验装置与高能时有些不同。为此，从Ｍａｘｗ ｅｌｌ＇ｓ 方程组出发详细推导了电子斜入射时适用于各能段的光学渡越辐射光强的空间分布公式。以此为基础建立了实验装置，并利用ＣＣＤ摄像机得到了４ ＭｅＶ 电子束流的ＯＴＲ光斑，为进一步的研究打下基础

Optical transition radiation in low energy region

Optical transition radiation (OTR) has been widely studied as a diagnostic means of electron beams in mid and high energy region. The distribution of OTR in low energy region does not concentrate in a very small solid angle in direction of reflection just like in high energy region, but distribute in a large solid angle. And it is very asymmetry in the case of oblique incidence. All of these cause the OTR set up in low energy region different from high energy region. Therefore, a general distribution formula of OTR intensity, which can be applied in any case, including oblique incidence, was derived from Maxwell's equations. A set up was built based on this formula. OTR images of 4MeV electron beams were obtained by CCD detector. This paper gives a suitable background for further study.