The Study Of Digital Data Analysis Method On GTAF

Neutron capture reaction is one kind of the important reactions in the nuclear energy engineering research. High precise data of neutron capture reaction cross-section are needed in the study of nuclear energy application, the partitioning and transmutation of the nuclear spent fuel, the nuclear astrophysics and the design of the nuclear reactor. People are request for the improvements of the accuracy on the neutron capture cross section all the while, so the method and the instrument for measurement need to be developed.A Ba F2 scintillation calorimeter with an ability of absorb γ-ray totally, the γ-ray Total Absorption Facility(GATF), dedicated on the measurement of(n,γ) reaction cross-sections, was constructed at China Institute of Atomic Energy( CIAE). The detector system is consist of 40 Ba F2 scintillator module, with the form of spherical shell,. Ba F2 crystal is the fastest inorganic scintillator, so it is beneficial to the neutron flying time measurement, further the neutron energy determention. And so on, neutron sensitivityof Ba F2 crystal is low. The prompt γ-ray released in the neutron capture reaction will be totally detected by the Ba F2 scintillation detector,Digital data acquisition technic based on Flash ADC is used in this experiment. The circuit can be easily connected and the data can be saved with full information compared to the traditional method. neutron capture event can be reconstructed by off-line data analysis.The digital data acquisition system and online monitoring system has been successfully built. The arrival time of γ rays detected by Ba F2 detector was determined by various timing methods. The compare of various timing method indicated that constant fraction discrimination and digital constant fraction discrimination will be used to measure the neutron energy of capture reaction in online experiment. Alpha and Spike had been identified from γ-ray by analysing pulse shape, and the energy spectra of 60 Co and 137 Cs were obtained. We designed the GTAF detector shield body and neutron absorber in sample.This thesis had established background suppression technologies. This work is very important for the GTAF in the future experiments.