SHINE束线站定时系统束团编号的数据采集

Data acquisition of bunch IDs in timing system of SHINE beamlines and end stations

上海硬X射线自由电子激光装置(Shanghai High Repetition rate XFEL(X-ray Free Electron Laser)and Extreme light facility,SHINE)是一个高重频XFEL装置,束线站定时系统需要为设备提供基于硬件的精确的X射线束团编号和定时触发。对于SHINE束线站单脉冲工作模式的设备,采集数据包以及对应时刻的束团编号信息,便于后续实验数据分析。设计了一个束团编号采集的测试系统,它基于Zynq-UltraScale+型片上系统(System-On-Chip,SOC)搭建,采用了白兔协议(White Rabbit)协议的定时系统环境。该测试系统通过FPGA夹层卡(FPGA Mezzanine Card,FMC)获取嵌入型从节点的束团编号,使用LwIP(Light weight Internet Protocol)协议搭建的TCP协议栈实现束团编号的采集。采用Basler相机对该系统进行了实验测试,并使用pypylon库来采集相机的数据。实验测试结果表明:该束团采集测试系统获得的束团编号数量和图像帧数相同,可以满足SHINE束线站对于束团编号采集的需求。

[Background]Shanghai High repetition rate XFEL(X-ray free electron laser)and Extreme light facility(SHINE)is a high-repetition-rate X-ray-free electron laser.The timing system of the beamlines and endstations must provide high-precision bunch IDs and a timing trigger for the equipment that works in single-pulse mode.[Purpose]This study aims to design a data acquisition(DAQ)testing system to simultaneously acquire X-ray bunch IDs with their corresponding detector data package for subsequent data processing.[Methods]This DAQ testing system was developed on the Zynq UltraScale+system-on-chip(SOC),and the White Rabbit protocol was employed for the timing system environment.A Bunch ID obtained from the FPGA mezzanine card(FMC)of the embedded White Rabbit node(WRN)was transferred to the server using a TCP protocol stack built on LwIP(light weight internet protocol).Finally,a Basler camera was employed to test this DAQ system,in which the pypylon library was applied to raw data acquisition software for camera snapshot whilst two channels of data were collected by an upper computer and saved to a database for comparison.[Results&Conclusions]The number of bunch IDs obtained by this acquisition test system is the same as that of image frames taken by Basler camera,which demonstrates that the testing system can satisfy the requirements of bunch ID acquisition in SHINE beamlines and endstations.