Design And Implementation Of The Time System For Daya Bay Experiment

The Daya Bay neutrino experiment,which is still under building, is one of the most important neutrino experiments of the world. There are 3 different measurement stations for the Daya Bay experiment. The time system of Daya Bay experiment is designed to provide time informations and clock signals for all these 3 stations. We used PowerPC and FPGA to design the time system and the following steps have been done:1. The design and implementation of the Daya Bay experiment time system's hardware. In order to make it easily to implement, we chose to use the PowerPC module and the optical-transceiver module for the time system. A mother board for all these modules and interfaces was designed. How to make all the modules and interfaces work perfectly was studied and discussed.2. The test of the optical-transceiver module. The Daya Bay experiment time system communicates with all the measurement stations through optical cables. An optical-transceiver module was designed and tested. Signal commission through the optical-transceiver has been done to make sure the module works as we wished. The relation between the delay of the signal and the length of the optical cable was studied.3. The design and implementation of the software for the time system. On the first hand, the kernel and software design for the embedded Linux was studied, for we ported an embedded Linux operating system to the PowerPC module. On the other hand, the decoding and encoding for the IRIG-B and Manchester codes were discussed, for the FPGA needs them to control the interfaces.The Daya Bay experiment time system was successfully finished and will play an important role in the measurement of the neutrino. The process of the system design discussed here is useful and helpful for the similar applications.