ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Possible measurement of extremely low level β-activities by the gas-flow GM detector in 2π geometry

M. Azduban

Laboratory of Radiobiology, Department of Biology, Faculty of Natural Sciences, P. J. Šafárik University, Košice

Abstract: A gas-flow GM-detector in 2π geometry with absorption and anti-coincidence shielding was used for measuring of extremly low activities of solid and liquid β-emitters. At 2.22 c. p. m. background it is possible to take measurements of samples 50 mm im diameter. Maximum weight of the solid sample is 8 g, the volume should not exceed 4 ml. The calibrating was done by means of potassium salts (40K). The minimum limit of the total activity for absorber thickness 20 mg/cm² is 0.9 . 10^-12 Ci. On the basis of the limit activity values achieved by ⁴⁰K it is shown the possibility of utilizing the known value of the total detection efficiency even for determination of the total activity of decay products ß mixture old 150 days at least. The limit total activity of 100 mg/cm2 sample for decay products mixture is 1.3—1.4 . 10^-12 Ci.

Full paper in Portable Document Format: 224a291.pdf (in Slovak)

Chemical Papers 22 (4) 291–299 (1968)