A multi channel high accuracy real time DAQ system for fast neutron spectrometer based on GEM-TPC

To sample the 720 channels signals with 100ns rising edge by over 60dB dynamic range, a 12bits 50Ms/s real time DAQ system has been designed for the Fast Neutron Spectrometer Based on GEM-TPC. This DAQ system is consisted of eight 64 channels FADC cards sampling the signals from the GEM-TPC and communicating with the computer. Caused by the randomness of the events and the large variation range of the data volume (nearly 60dB) from the GEM-TPC, a bit intelligent functions need to be designed to meet the requirement of the real time data acquisition with nearly lkls event rate (each event will generate 1~120 signals with 0.25~3.5us pulse width). The ´complete digital design method´ and the ´concatenate encoding method´ are also applied in this DAQ system to keep the stability and the high accuracy for the signals processing and communicating. With the design mentioned above, this DAQ system could adapt over 2k/s event rate and over 60dB dynamic range.