中国散裂中子源快循环同步加速器主准直器的设计与研究

为满足强流加速器对准直器高散热性能、高抗辐射性能、超高真空、高定位精度、高稳定性和在线实时调整等特殊要求,在CSNS/RCS主准直器设计时针对结构方案和控制方案进行了详细设计和研究,针对关键部件:刮束器、真空盒、驱动装置和远程快速拆卸装置等设计难点进行了阐述,在设计中使用ANSYS完成了刮束器的热分析及支架强度和变形校核,用FLUKA程序对辐射屏蔽进行了分析和设计,确保主准直器设计的可靠性。     

Fluorescence lifetime measurement from a designated single-bunch in the BEPCⅡ colliding mode

Fluorescence lifetime measurement in the time domain requires excitation from a well separated single bunch using synchrotron light sources. In the colliding mode of the Beijing Electron Positron Collider Ⅱ (BEPCⅡ), a hybrid filling pattern was realized such that a single bunch was placed in the middle of a large gap between two multi-bunch groups. Detection of fluorescence lifetime, based on the excitation of the light pulse from this designated single-bunch, was established at Beamline 4B8 of the Beijing Synchrotron Radiation Facility (BSRF). The timing signal of the BEPCII was utilized as a trigger to gate this fluorescence event. L-Tryptophan amino acid, a known lifetime standard, was selected to assess the lifetime measurement performance. The measured lifetime was consistent in both colliding and single-bunch mode with the time resolution down to 450 ps. Moreover, both the bunch purity and the fine structure of the hybrid filling pattern were characterized.     

BEPCⅡ控制系统

北京正负电子对撞机重大改造工程BEPCⅡ于2001年启动. BEPCⅡ采用双环交叉角对撞方案,使用微包络函数(micro-β)和多束团对撞以提高亮度. 先进的低温超导技术将用于对撞机的设计中. BEPCⅡ控制系统采用分布式体系结构和系统集成工具EPICS(Experimental Physics and Industrial Control System)进行开发. 控制系统的设计采用了国际先进技术. 目前系统正在建造之中, 主要系统完成了软硬件开发和实验室调试, 于2006年3月进入现场安装.预计BEPCⅡ储存环2006年10月可以开始带束流调试. 本文将介绍BEPCⅡ控制系统及其进展.     

中国散裂中子源快循环同步加速器主剥离膜设计

设计了中国散裂中子源(CSNS)快循环同步加速器(RCS)注入区的主剥离膜装置。为降低研制难度和成本，提高运行可靠性，选择了回转体式的结构。根据在线可调性、高稳定性、高定位精度和超高真空等技术难点，给出了CSNS/RCS主剥离膜的具体结构方案和控制方案。利用ANSYS有限元分析软件和材料力学原理，对设备的核心部件不锈钢同步带进行了模拟计算和理论分析。