Determination of α-radionuclides in environmental samples by large area grid ionization chamber / 中华放射医学与防护杂志

ABSTRACT

Objective To develop the method of analyzing α-radionuclides using large area grid ionization chamber.Methods Ultrasonic dispersion and vacuum drying system was used to prepare sample source,large standard thin source and plutonium plane source were used to optimize the working condition of spectrometer,and calibrate the instrument for analyzing α emitters.The certified reference materials (GBW04127) were used to verify the accuracy of the method.Results The non-linearity of calibration curve for standard thin sources of neptunium,plutonium and americium was less than 0.2％,and the resolution were 112,84 and 106 keV,respectively.The counting efficiency was 31.2％ for the large standard thin source.The values of specific activity measured in this way were in good agreement with those of the certified reference materials.232Th,238U,230Th,234U/226Ra,210Po,222Rn and 218Po were analyzed in a uranium mineral sample,and their specific radioactivity values were 5.3,3.8,35.6,21.4,27.0,19.6 and 11.1 Bq/g,respectively.Conclusions The method can be used to analyze α spectrum quickly in low-level radioactive environmental samples.