Study on the composite measurement method for micro-structure and profile of electron beam

对于复合测量方法，我们提出了几种新的测量技术。研究结果如下：(A)基于驻波测量的直线加速器波束微脉宽测量：提出了一种新的基于时间域到空间域变换的时间脉宽测量方法。它只需要测量空间驻波分布。只需使用低频检测器系统(如示波器、A/D转换器等)即可检测到这些分布。数值演示和实验结果表明了该方法的有效性。(2)电磁场测量横向轮廓估计：为了验证横向轮廓实时测量系统的有效性，我们编制了包括伪信号发生器、卡尔曼滤波和并行遗传算法在内的软件系统。该系统可以模拟光束轮廓随时间变化的情况。Est…将更多的仿真结果与给定的轮廓进行比较。时间响应分析的结果表明，除了极少发生的不稳定外，该系统给出了几乎良好的估计。c X射线分幅相机测量电子束：我们研究了用于直线加速器电子束轮廓二维测量的X射线分幅相机的空间分辨率。在测量空间分辨率时，一般采用测试图。然而，对于软X射线来说，并没有找到良好的测试图版。为此，我们提出了一种仅使用刀口的虚拟测试图算法。提出了利用磁场提高空间分辨率的方法。(4)超高速相机的同时改进：指出了超高速相机在亚纳秒级快门工作时存在的图像符合特性问题，并提出了考虑电极形状的改进方法。数值分析结果表明，时间色散由30皮秒减少到5皮秒。较少

We proposed several new measurement techniques for composite measurement method. The results of them are as the followings.(a) Measurement of micro-pulse width of LINAC beam using standing wave measurement: We propose a new technique based on transformation from the time domain into the spatial domain to determine the time pulse width. It requires measurements of only spatial standing wave distributions. These distributions can be detected with only use of the low frequency detector systems (e.g., oscilloscope, A/D converter etc.) The availability of this technique is shown by the numerical demonstration and the result of experiments.(b) Transverse profile estimation with measurement of electromagnetic fields: To demonstrate the availability of real time measurement system for transverse profile, we made the software system that includes a pseudo signal generator, the Kalman filter and parallel genetic algorithms. This system can simulate time dependent changes of beam profile. The est … More imated result is compared with the given profile. As the result of the time response analysis, we showed this system gave us almost good estimations except rare occurred instability.c Electron beam measurement by X-ray framing camera: We investigated the spatial resolution of X-ray framing camera for 2-dimensional measurement of LINAC electron beam profile. In generally, the test chart is applied to measure the spatial resolution. However, good test chart is not found for the soft X-ray. Thus, we propose a new technique named virtual test chart algorithm that use only a knife edge. Further we proposd a method of improving the spatial resolution using the magnetic field.(d) Simultaneity improvement of the ultra-high speed camera: We pointed out a problem about coincidence characteristics of image when ultra-high speed camera operates with sub-nano-second shuttering, and proposed the improvement way considering the shape of electrode. As the result of numerical analysis, the disperse in time is reduced from 30 pico-seconds to 5 pico-seconds. Less