神龙一号电子束质心运动测量研究

 在强流直线感应加速器中，电子束质心位置的控制是一项重要技术，要达到较好的控制效果，前提是对电子束质心位置进行准确的测量和定位。针对具有时间分辨的电子束质心位置的测量和确定，介绍了测量实验系统的建立和数据处理两个方面的研究工作。该处理方法在实际应用时能够将电子束质心位置的误差控制在1～2个像素内。用高速分幅相机以10 ns的时间间隔、3 ns的曝光时间获得了神龙一号加速器在漂移段出口处的电子束质心运动情况。结果表明：束的质心主要在半径为0.5 mm的区域内运动，束斑直径dFWHM值分别为8.4，8.8，8.5，9.3和7.6 mm，测量结果可以为束的调控提供准确参数。

Measurement of centroid trajectory of Dragon-Ⅰelectron beam

The control of the electron beam in an intense current linear induction accelerator(LIA)is very important.The center position of the electron beam and the beam profile are two important parameters which should be measured accurately.The setup of a time-resolved measurement system and a data processing method for determining the beam center position are introduced for the purpose of obtaining Dragon-Ⅰ electron beam trajectory including beam profile.The actual results show that the centroid position error can be controlled in one to two pixels.The time-resolved beam centroid trajectory of Dragon-Ⅰ(18.5 MeV,2 kA,90 ns) is obtained recently in 10 ns interval,3 ns exposure time with a multi-frame gated camera.The results show that the screw movement of the electron beam is mainly limited in an area with a radius of 0.5 mm and the time-resolved diameters of the beam are 8.4 mm,8.8 mm,8.5 mm,9.3 mm and 7.6 mm.These results have provided a very important support to several research areas such as beam trajectory tuning and beam transmission.