A. J. Kordyasz1, A. Bilewicz2
1 Heavy Ion Laboratory, Warsaw University, 02-097 Warsaw, Poland,
2 Department of Radiochemistry, Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland
The method for fast measurement of 226Ra in low radioactive aqueous solutions by adsorption of radium on a-crystalline manganese dioxide and registration of a-particles from emanated 222Rn and its daughters has been elaborated. A large-area (64 cm2) silicon detector was used for a-particles registration. The method was tested using manganese dioxide samples with adsorbed 226Ra of radioactivity: 0.5 Bq, 1 Bq, 2 Bq, 10 Bq and 50 Bq, measured from 1 to 42 h. The time for chemical preparation of the sample and measurement was not greater than 6 h.