The clock system for LHAASO WCDA based on reduced White Rabbit  

作　　者：LI Cheng LIU Shubin SHANG Linfeng CAO Ping AN Qi 

机构地区：[1]State Key Laboratory of Particle Detection&Electronics,Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China [2]ZAnhui Key Laboratory of Physical Electronics,Hefei 230026,China

出　　处：《Nuclear Science and Techniques》2012年第4期230-236,共7页核技术（英文）

基　　金：Supported by the National Natural Science Foundation of China(No.11175174 and No.11005107);the Knowledge Innovation Program of the Chinese Academy of Sciences(KJCX2-YW-N27)

摘　　要：Due to the large scale of Water Cherenkov Detector Array in Large High Altitude Air Shower Observatory, the frontend digitization is imperative.Thus a clock distribution system is desired,which broadcasts the synchronous clock signals with low jitter to the frontend electronics distributed in the field of 90 000 m^2.The White Rabbit protocol provides an option,which has been approved to achieve sub-ns accuracy and ps jitter in the synchronization of around 1 000 nodes in the order of 10 km.But the hierarchy of the original is too complex for Large High Altitude Air Shower Observatory application.Thus we proposed a reduced scheme based on the White Rabbit protocol.The validation circuit shows that the clock skew due to the fiber length difference can be adjusted to less than 25 ps and the clock jitter is less than 62 ps.Due to the large scale of Water Chereiakov Detector Array in Large High Altitude Air Shower Observatory, the frontend digitization is imperative. Thus a clock distribution system is desired, which broadcasts the synchronous clock signals with low jitter to the frontend electronics distributed in the field of 90 000 m^2. The White Rabbit protocol provides an option, which has been approved to achieve sub-ns accuracy and ps jitter in the synchronization of around 1 000 nodes in the order of 10 km. But the hierarchy of the original is too complex for Large High Altitude Air Shower Observatory application. Thus we proposed a reduced scheme based on the White Rabbit protocol. The validation circuit shows that the clock skew due to the fiber length difference can be adjusted to less than 25 ps and the clock jitter is less than 62 ps.

关 键 词：时钟系统 白兔 基础 同步时钟信号 探测器阵列 分配系统 电子领域 层次结构 

分 类 号：TN931.2[电子电信—信号与信息处理] TQ925.2[电子电信—信息与通信工程]