Design Of New FPGA-based Multi-channel Analyzer For Gamma Spectrum

Multi-channel analyzer for γ spectrometer is mainly used to obtain and analyze theγ-ray spectrum,it has been widely used in national defense,medicine and other fields,since its birth.Especially in the field of nuclear detection technology,it is an important instrument for basic scientific research.With the development of digital electronic technology,the new multichannel γ spectrometer has many obvious advantages.At present,the new multichannel γ spectrometer has been commercialized in foreign countries,and our country is still in the development stage in this field.Therefore,the research of the new multichannel γ spectrometer has certain positive significance.In this paper,based on the FPGA chip EP4CE10F17C8 N of Altera,we studied the key technologies of the new multi-channel γ spectrometer.Firstly,we proposed a modular design scheme based on the principle of γ energy spectrum measurement,and selected the core components of the main modules.Secondly,we designed the hardware circuit of this paper,which mainly includes the sampling circuit with AD9226 as the core,the signal processing circuit with FPGA and STM32 as the core,and the data communication circuit with W5500 as the core.Thirdly,we focused on the FPGA peak extraction algorithm,optimized and improved the general threshold processing algorithm,and put forward the dynamic threshold processing algorithm.With this algorithm as the core,we designed a software system with the following main functions,such as data acquisition,peak extraction,data storage,data communication and spectral display.Finally,the basic performance of a new multichannel γ spectrometer based on the above scheme was tested.The results showed that the new multi-channel γspectrometer has good integral nonlinearity,differential nonlinearity,energy resolution and stability,and verifies the feasibility of the dynamic threshold processing algorithm.