Study of Very Precise and Stable Beam Optics Controls in the Next Generation Linear Accelerators

在高能粒子和同步轨道光物理实验中，为了推进研究，需要获得精确的信息。为了满足下一代直线加速器（如直线对撞机、SASE自由电子激光器和高强度质子直线加速器）对高强度和高稳定性粒子束的要求，我们研究了一种独特的工具来观察束流的光学质量以及束流和位置，研究了提高束流光学稳定性的方法，建立了八电极束流监测器和四电极束流监测器，其可被转换成射束能量扩展和发射度信息。为了提高束流质量的稳定性，对注入KEKB的束流安装了反馈和监视程序。为了提高稳定回路的响应时间，我们还设计了一个快速读出系统，这些无损的实时束流信息与硬件稳定性和尾流场的非线性束流光学进行了比较，从而加深了我们对束流质量的理解。随着控制和仪表系统的发展，进一步的优化算法也被研究。

In the high-energy particle and synchrotron-orbit light physics experiments it is demanded to acquire precise information in order to advance their studies. It is important to provide high-intensity and high-stability particle beams especially in the next generation linear accelerators like a linear collider, SASE FEL, and a high-intensity proton linac.In order to meet those requirements we investigated a unique tool to observe the optical quality of beams as well as the beam current and position, and studied a method to improve the stability of the beam optics.Eight-electrode beam monitors were established as well as four-electrode monitors to retrieve, a transverse beam profile information, which can be translated into beam energy spread and emittance information. Thus it acts as a nondestructive beam quality monitor.Feedback and surveillance procedures were installed for the injection beams to KEKB in order to improve the stability of the beam quality. A fast read-out system was also developed to enhance the response time of the stabilization loops.Those nondestructive and real-time beam information advanced our understanding on the beam quality comparing them with hardware stabilities and nonlinear beam optics of wake fields. Accompanied with the developments of the control and instrumentation systems, further optimization algorithms are investigated.