摘要: Back-n是中国散裂中子源（CSNS）的反角中子束线，适用于精密核数据的测量。该装置的谱仪读出电子学采用共性化设计方法，利用高速波形数字化技术精密采集探测器输出信号波形。为完成对两通道、1 GSps，12 bit采样数据的读出和板载外设的控制，可以使用一种基于FPGA的高速数据实时读出方法。该方法不仅实现了数据接收、缓存上传等通用需求，还通过软件配置满足了实时触发处理等针对特定物理实验的特性需求。此外，FPGA的灵活使通过固件更新支持新实验或添加新功能成为可能。测试结果表明，该方法能够适应Back-n波形数字化模块高速数据读出的需求，峰值处理能力可达24 Gbps，符合物理实验需求。目前，基于实时读出方法实现的波形数字化模块已完成中子源谱仪实验现场的安装，工作稳定。


Back-n is a back-streaming beam line at China Spallation Neutron Source, which is suitable for measure nuclear data precisely. The readout electronics of the spectrometers at this facility adopts general-propose design method, using high-speed waveform digitizing technology to record the detector output signal accurately. To read out two channels, 1 GSps, 12 bit sample data and control on-board devices, the real-time readout method of high-speed data based on FPGA technology can be considered. The method not only realizes the general requirements of the data upload, but also processes real-time triggers according to experiments via configuration. In addition, due to the flexibility of FPGAs, new experiments or new features can be supported through firmware updates. The test results show that the method is suitable for the high-speed data readout of field digitizing module at Back-n and peak capacity reaches up to 24 Gbps, which meets the requirements of the physical experiment. The field digitizing modules based on this method were installed at Back-n and work normally.