Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2012, Vol. 23 ›› Issue (4): 230-236 doi: 10.13538/j.1001-8042/nst.23.230-236


The clock system for LHAASO WCDA based on reduced White Rabbit

LI Cheng(1,2) LIU Shubin(1,2,) SHANG Linfeng(1,2) CAO Ping(1,2) AN Qi(1,2)   

  1. 1 State Key Laboratory of Particle Detection & Electronics,Department of Modern Physics,University of Science and Technology of China,Hefei 230026, China 2 Anhui Key Laboratory of Physical Electronics,Hefei 230026,China
LI Cheng, LIU Shubin, SHANG Linfeng, CAO Ping, AN Qi. The clock system for LHAASO WCDA based on reduced White Rabbit.Nuclear Science and Techniques, 2012, 23(4): 230-236     doi: 10.13538/j.1001-8042/nst.23.230-236


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.

Key words: White Rabbit, Skew, Jitter, Digital dual mixer time difference, Time-to-digital converter