Study On Alpha Dual Channel Spectrum Radon Measurement With Pump Suction

With the development and progress of human civilization,people’s living standards are getting better and better.At the same time,the development of science and technology has made an impact on pepole’s living environment.The state also attaches great importance to the improvement of the ecological environment.In recent years,radioactive contamination has become one of the hot topics.Among them,the measurement of radon and their progenies in the construction of houses or in geological exploration,environmental monitoring,and water search has been used as an important technical means of radioactive detection.Under this background,relying on the Chengdu City Science and Technology Bureau’s innovation and entrepreneurship project,a high-sensitivity gold-silicon surface barrier detector was selected as the main detection element,and an alpha-spectral measurement technique as the core was designed to design an independent dual probe.The system alpha spectrum spectrometer solves a series of problems such as long measurement time,large influence of temperature and humidity,and the like.This paper first elaborates the background of the hazards produced by the radon and its progneies,as well as the corresponding decisions made by relevant organizations and countries in the world about the field of radioactive contamination and geological exploration of radon.Based on this,the measurement method of radon was introduced,and the principle of α-spectrum radon measurement was introduced.By testing the experimental data,a double φ30mm gold-silicon surface barrier semiconductor detector was selected and the volume of the double sampling cavities was designed.According to the actual measurement data,it is concluded that the measurement sensitivity of this system can reach 0.2cpm/pCi/L.The dual-channel α-spectrum pump-sucking radon monitor is based on the STM32F103RCT6 microcontroller,and performs measurement and analysis for air radon,soil radon and water radon.When measuring air and water radon,any channel can be selected to complete the measurement.For the measurement of soil radon,taking into account the measurement environment,dual-channel measurementsare taken in turn to complete high-efficiency radon measurement.The system integrates the temperature and humidity measurement module.In the software part,the temperature and humidity correction algorithm compensates for the effect of temperature and humidity on the measurement of radon,and improves the accuracy of data measurement.The implementation of α-quantity measurement andα-spectroscopy measurement were discussed.In consideration of the influence of radon gas in actual work,α-spectrum measurement method was selected to effectively distinguish the source of radon and thorium gas.The hardware implementation of the preamplifier,main amplifier,multi-channel pulse amplitude analyzer and auxiliary circuit are discussed separately,introducing the basic functions,implementation principles,etc.The low-power power circuit provides basic guarantee for the efficient operation of the radon detector.Divin touching screen is used to realize human-computer interaction,and the operation is simple and convenient.Finally,Selecting the STM32 library function and bit-band operation to achieve the software part of the preparation,complete the instrument design.Through experimental observations,it shows that the instrument has good stability and accuracy after the standard chamber calibration.Through the instrument response time test,the background subtraction algorithm was determined to prevent the background accumulation from affecting the accuracy of the measurement data.The practical application shows that the radon detector is of reasonable design,and the performance and parameters of the instrument meet the national metrological verification standards "Testing Radon"(JJG825-2013)and "Civil Construction Project Indoor Environmental Pollution Control Regulations"(GB50325-2010).The dual-channel alpha-spectrum pumping-type radon measuring instrument designed in this paper can directly operate through the touch screen and display the concentration of air radon,soil radon,and water radon.It has the advantages of simple and reasonable structure design,with easy carry and easy use.It can be widely used in environmental monitoring,exploration of uranium resources,exploration of concealed faults and ground fissures in building foundations,and monitoring of distribution of gasified coal gasifier fire zones.