Design And Implementation Of Electrically Controllable Pulsed Neutron Generator Console

Pulsed neutron generator has many characteristics,including high neutron energy,good monochromaticity,controllability and use of safety.It can produce pulsed neutrons for elemental analysis of the material,mainly used in explosives detection,oil well logging and qualitative analysis of coal and so on.In order to improve the accuracy of elemental analysis,this paper designs an electronically controllable pulsed neutron generator console for ZFD-1 eramic neutron tube with drive-in target of Northeast Normal University.This paper analyzes the working principle and basic structure of ZFD-1 eramic neutron tube with drive-in target,and further describes the design process of hardware and realizing method of software in detail.On the design of hardware,based on the gas holder driving power supply,ion source driving power supply and high voltage driving power supply in traditional console,DA output function,AD data acquisition function,serial communication function,wireless communication function and timing function etc with DSP as the core controller are realized.The pulse timing control circuit based on CPLD as a second controller realizes the function of the trigger pulse of the ion source and the synchronization pulse.The software consists of C programming language for DSP,Verilog HDL design for CPLD and development of upper computer.Traditional console is less reliable because of communication protocol.In this paper,the Modbus-RTU protocol is selected to further enhance the reliability and fault tolerance of the system.The electronically controllable pulsed neutron generator console has three modes of operation,DC mode,single pulse mode and compound pulse mode.Under the corresponding working mode,the neutron generator will produce DC neutrons,single pulse neutrons and compound pulse neutrons.In the DC mode,the yield stability of the neutron generator has obviously improved.Both theory and experiment have proved that the accuracy of element analysis can be improved further when the neutron generator works in pulse mode.In the pulse mode,the neutron generator works in fast-slow pulse state.In the fast pulse,the neutron emission is used to detect the substance suitable for fast neutron inelastic scattering(n,n ').During the interval,the neutron emission is used to detect the substance that is suitable for slow neutron radiation capture(n,?).After the slow pulse,the neutron emission is used to detect the material that is suitable for neutron activation.Actual test results of the electrically controllable pulsed neutron generator console: The adjustment range and precision of storage current are 0-1.2A and 0.5mA,the adjustment range and precision of ion source voltage are 0-2500 V and 1V,the adjustment range and precision of high voltage source voltage are 0-130 kV and0.06 kV.In the DC mode,the stability of the neutron generator is 2%.In the single pulse mode,the minimum pulse width is 10 us,and the maximum pulse frequency is10 kHz.The neutron generator has been used in National Major Scientific Instruments Development Project “ Development and application of real time online testing instrument for industrial material composition(2013YQ040861)”.It meets the overall requirements of the project,and runs well.