| Real-time online inspection technology based on PGNAA method for industrial ingredients can be widely used in coal, cement and metallurgical production process-es, to achieve the optimal control of production processes, It can improve production efficiency, optimize the use of resources, reduce energy consumption, reduce environ-mental emissions and so on. PGNAA technology with high sensitivity, high accuracy characters has become the best choice to meet the needs of industrial bulk material an-alyzing.With the rapid development of computer technology and modern mathematical analysis methods,a US company named gamma metrics has developed the first elemen-tal composition analyzer that can be used for industrial site. This technic wac developed a little later in China,the instruments that designed before has a big gap compared with similar foreign products. In this regard, the Ministry of Science and Technology of China set up to carry out special research of "based on instantaneous ?-ray neutron ac-tivation analysis technology of industrial materials on-line real-time detection system"as a national major scientific equipment development in 2013.The object of this project is to study the key technology of the high precision on-line detection system for bulk material composition in the process of industrial production.Among them, the key technologies that need to be focused on are as follows: "the development of small neutron source with high yield and long life" and the development of high count rate detector system”. The work presented in this paper is the development of detector readout electronics system.For the PGNAA application data acquisition system design requirements, the sys-tem has a high pass rate and energy spectrum measurement accuracy. At the same time,how to ensure the stability of the system for a long time is also a key issue. In view of these applications, the main contents of this paper are as follows.In this paper, a high count rate and high precision gamma ray spectrum measure-ment system is established. The improved shape detector electronics system design by using multilevel filter readout system, shaping circuit and fast recovery circuit on the baseline detector signal conditioning, signal accumulation decreased from counting loss caused, improve the system by counting rate. The system using high-speed ADC fast waveform sampling, and uses advanced digital filtering and fast peak search al-gorithm to improve the measurement accuracy and the processing speed, decrease the measurement of dead time to meet the real-time measurement requirements, accurate measurement of the high count rate level characteristics of gamma energy spectrum.The test results show that the system can meet the measurement requirements in prac-tical application conditions, improve the counting rate and measurement accuracy, and effectively improve the analysis accuracy of the element composition.The innovation of this paper is mainly about the following points:1) This paper presents a high counting rate, high signal-to-noise ratio gamma ray spectrum readout system structure, and in the application of PGNAA to improve the sig-nal processing speed and measurement accuracy, improve the efficiency and accuracy of element analysis, to meet the demand of real-time measurement.2) Research of high count rate detector based signal readout, fast signal forming processing, fast baseline restoration and high speed signal processing method, decrease counting loss caused by the signal accumulation under the condition of high count rate,reduce the dead time of the pulse amplitude measurement.3) design a prototype system which can meet the requirements of high resolution and high precision gamma ray spectrum measurement, which can be applied to the analysis of industrial materials based on PGNAA method. |
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