Research On The Data Acquisition And Processing Of Digital Coincidence

Coincidence Counting Method is used to research the events relating to time ordirection in the process of nuclear decay and nuclear reactions. Whilst it has beenwidely applied in various fields of nuclear technology, there are a number ofcomplications which may need careful consideration. These complications include theunwanted detection of “accidental” coincidences, the decay scheme of the nuclide,pulse pile-up, the mean time-delay between β and γ pulses, spurious pulses and thecounting losses due to deadtime. In the decades since the introduction of coincidencecounting, a large amount of effort has been devoted to reducing the uncertainty inmeasurement caused by these effects，including derivation of more precise correctionsformulae, advances in the design of radiation detectors, introduction of alternativemethods and the development of new instrumentation.Digital Coincidence Counting (DCC), based on the digital nuclear pulseprocessing techniques to realize coincidence measurement, is an inevitable trend forcoincidence counting device. With fully extraction and analysis of the amplitude, time,waveform information of pulse signal, DCC can increase the accuracy ofmeasurement and strengthen the ability of data analysis. At present, there are anumber of institute carried out relational research work. Furthermore, theInternational Commission for Radionuclide Metrology (ICRM) has instructed itsRadionuclide Metrology Techniques Working Group to develop a means offacilitating direct comparison of the performance of these various DCC systems.After many researches and analyses on the sense and principle of DCC, a designscheme for digital coincidence was proposed in this paper. With sampling the detectorsignals to the computer by the high speed data acquisition card, the critical parts ofscheme can be crystallized and implemented by MATLAB software. Moreover, a software interface was designed for DCC based on VB6.0software. Finally, A DCCsystem was constructed for the radioactivity of60Co experiment.To verify effectiveness and feasibility of the scheme designed in this paper,Comparative Experiment was conducted with the conventional coincidencemeasurement, and also referred the value calculated from the original radioactivity.The experiments show that the scheme of DCC is really practical, and its algorithmsare vailid. This study is of great significance to the future research on digitalcoincidence technology...