Determination of emission probabilities of gamma photons in the decay of (56)Co.
The emission probabilities of gamma photons in the decay of (56)Co were determined at Czech Metrology Institute (CMI) by means of an HPGe detector. This detector was calibrated experimentally and by MCNP-computation in the energy range from 40 to 2754keV for a point source geometry and source-to-detector distance of 25cm. Experimental and computed peak and total efficiencies were compared and calibration curves were determined. Full-peak efficiencies were calculated for all (56)Co gamma-ray energies, and were used to calculate the emission probabilities. A set of point sources was prepared from a (56)Co solution. The solution was standardized using the 4pibeta-gamma coincidence method, and an ampoule was sent to international reference system for activity measurement of gamma-ray emitting radionuclides (SIR). Each point source was measured with the HPGe detector at a source-to-detector distance of 25cm. Coincidence emission probabilities of all the gamma photons were calculated and used to determine the summing correction factors.
Dryak
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Czech Metrology Institute-Inspectorate for Ionizing Radiation, Radiova 1, CZ-102 00 Prague 10, Prague, Czech Republic. pdryak@cmi.cz
Kovar
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