发射度是反映加速器束流品质的重要物理参数，对于加速器的研制、束物理研究及束的实际应用，均具有重要的意义；随着研究水平的提高，对束发射度的精确测量需求日益紧迫，但发射度的测量本身就具有较大难度，尤其在需要了解其发散角分布情况时，这一直是加速器技术研究中一个重要方面的研究课题；发射度的测量在很大程度上体现在发散角的测量上。切伦科夫辐射是当介质中的带电粒子速度大于光在该介质中的速度时产生的一种方向性极好的光辐射，由于其方向严格地与带电粒子的运动方向相关，携带了带电粒子的方向信息，可以利用这种特性进行束发散角及其分布的测量技术研究。本项目将利用切伦科夫辐射原理进行脉冲电子束发散角及分布的时间分辨测量技术研究，研究工作主要在透明薄膜靶材料的库仑力影响、薄膜的支撑技术研究以及成像光学系统原理、弱图像信息获取技术等方面展开，并建立测量研究的实验装置，实现脉冲电子束2～3个时间分辨的测量结果。

The emittance is the one of the most important parameters of electron beam. It plays an important role in accelerator development, studying on the beam physics and the actual applications of the high current beam. The precision measurement technology for beam emittance is prerequisite for farther study for accelerator. But it is a difficult technology and it is more difficult to measure the electron beam divergence distribution. The emittance measurement is mainly determined by beam divergence measurement. Cerenkov radiation has the advantage of good orientation. The radiation orientation is strictly correlative with the moving direction of the electron and it brings the angular divergence information of the electron beam. This is the foundation of the measurement technology for the beam divergence and distribution. This item will carry out the study of the electron beam divergence and distribution measurement technology basing cerenkov radiation. This item will intend to study on the influence of coulomb force in the film target of transparent material, the tightening and spreading technology for film target, the imaging principle, the image capturing technology for a faint image. The experiment will also setup and 2 to 3 time-resolved results for one electron beam pulse is our goal .