Research On Measuring Of Unbound Radon Daughters Based On Imaging Plate

Radon(Rn222)and its daughters produce about half of the public dose of natural radiation,which is the largest source of natural radiation exposure.Quail and its daughters are also considered to be the second leading cause of lung cancer.As people’s living standards and health continue to improve,the impact of cockroaches on people is also getting more and more attention.To evaluate the radiation dose of cockroaches and their daughters to the human body,it is necessary to accurately measure the concentration of scorpion,the unbound body of scorpion.State fraction and its particle size distribution.Image Plate(IP)is a new type of two-dimensional detector with two-dimensional plane measurement,high sensitivity,large detection area,and reusability.It is widely used.In order to accurately measure the imaging plate of unbound scorpion,this paper carried out the following work:(1)The imaging plate identifies the alpha particle track count and its detection efficiency of different energy alpha particles in the scorpion body.The algorithm of α particle track recognition and counting by imaging plate was realized by Matlab,and the experimental verification was carried out.The different detection efficiencies of different energy alpha particles of scorpion body on imaging plate were studied by using α standard source and scorpion body source.The detection efficiencies of IP for RaA and RaCα particles were 0.224±0.017 and 0.282±0.021,respectively.(2)The imaging plate measurement of the concentration of radon progeny was realized and compared with the α spectrometer.The results show that in the high,medium and low three kinds of radon progeny,the imaging plate and the α spectrometer are measured according to the Thomas three-segment method,and the imaging plate can better measure the concentration of the radon progeny,and the measurement results are measured by the α spectrometer.The maximum relative deviations of RaA,RaB,and RaC concentrations were 14.35%,12.20%,and 10.34%,respectively.(3)Under the flow rate of 1-6L/min,the imaging plate was used to measure the collection efficiency and the ratio of the positive and negative ratio of the metal mesh of the unbound scorpion,and the results showed that the selected four kinds of metal screens(30)The measured values of the target,100 mesh,200 mesh,and 400 mesh are basically consistent with the predicted values of the previous theory.On the basis of this,it is preferred to measure the metal mesh in the unbound state scorpion body,and the imaging plate measurement of the unbound scorpion body is realized.The experimental study on the variation of unbound scorpion in different aerosol concentrations was carried out.The results showed that the unbound fraction of scorpion decreased with the increase of aerosol concentration.When the aerosol concentration was too high,RaC The unbound state share is basically undetectable.(4)According to the metal mesh collection efficiency theory,the GSA metal mesh group(30 mesh,100 mesh,200 mesh,400 mesh)was set up.The imaging plate was used to measure the count of each metal mesh and inverted by Twomey algorithm.Imaging plate measurements of unbound state scorpion particle size distribution were achieved.In this paper,the factors affecting the accurate measurement of the scorpion imaging plate are studied in detail,and the imaging plate of the scorpion body,the unbound scorpion body and its particle size distribution is accurately measured,and the unbound scorpion body is The experimental study of the law of change.The research in this paper lays a foundation for the future use of imaging plates to realize large-area sampling membranes of scorpion bodies,simultaneous measurement of multiple sets of samples,and accurate evaluation of scorpion body dose.