对利用从铀矿石中提取得到的227 Ac制备的固体219 Rn源进行了γ能谱分析，确定了227 Ac的4个子体核素227 T h、223 Ra、219 Rn和211 Bi的活度，并分析了能对219 Rn造成干扰的222 Rn、220 Rn母体核素226 Ra、224 Ra的活度。待227 Ac及其子体达到放射性平衡后，通过测量227 Th的235.97、256.25 keV ，223 Ra的154.21 keV ，219 Rn的401.81 keV ，211 Bi的351.059 keV共5条γ射线，最终确定固体219 Rn源中227 T h、223 Ra、219 Rn和211 Bi的活度为（1069±3）、（1079±5）、（1095±13）、（1096±14）和（11089±4） Bq ，固体219 Rn源的平均活度为（1093±8） Bq；通过测量224 Ra子体212 Pb的238.632 keV、208 T l的583.191 keVγ射线以及226 Ra子体214 Bi的609.312、1120.287 keV γ射线得到226 Ra与224 Ra的平均活度分别为5.12 Bq及0.433 Bq ，远低于固体219 Rn源的平均活度，说明固体219 Rn源放射性纯度较高。以上结果表明，此源有望制成标准固体219 Rn源以用于延迟符合法测223 Ra、227 Ac装置的刻度。%Radioactivity purity of the solid 219 Rn source made using 227 Ac extracted from uranium ore were determined by γ‐spectrometry .The activities of 227 Th ,223 Ra ,219 Rn and 211 Bi produced by the decay of 227 Ac and the contents of 226 Ra ,224 Ra w hich generates 222 Rn ,220 Rn to affect the purity of actinide in this source were analyzed after 227 Ac in radioactive equilibrium with its daughter nuclides . The γ‐ray energy used for the determination of these daughter nuclides of 227 Ac are 235.97 ,256.25 keV for 227 Th , 154.21 keV for 223Ra ,401.81 keV for 219Rn ,and 351.059 keV for 211Bi .Through the analysis ,the results are acquired that their activities are (1 069 ± 3 ) , (1 079 ± 5 ) , (1 095 ± 13) ,(1 096 ± 14) and (11 089 ± 4) Bq respectively ,and the average activity of solid 219 Rn source is (1 093 ± 8) Bq .The activities of 226 Ra and 224 Ra in this source are 5.12 Bq and 0.433 Bq respectively by the γ‐ray energy as follows :238.632 keV of 212Pb,583.191keVof208Tlfor224Ra,and609.312,1120.287keVof214Bifor226Ra,as they are all far below (1 093 ± 8) Bq ,so the radioactivity purity of the solid 219 Rn source is very high .The results show that the solid 219 Rn source can be developed to the stand‐ards for the efficiency calibration of the delayed coincidence counting system .
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