Activity measurements with radionuclide calibrators in the Czech Republic

Since radionuclide calibrators are used in nuclear medicine for the determination of the activity of radiopharmaceuticals administered to patients, it is important to ensure their long-term accuracy. Results of the checks performed in the Czech Republic during the year 2002 are given, together with a short overview of previous years. For the CMI 4πγ ionization chamber, against which all the calibrators are checked, we calculated the response function and basic characteristics by a Monte Carlo method, using the MCNP4C code.