Ionizing Radiation Metrology Laboratory

Head of the laboratory  dr. Arūnas Gudelis,
phone +370 52644855

The Ionizing Radiation Metrology Laboratory (IRML) maintains the National standard of radionuclide activity, which has a special name - becquerel (Bq); 1 becquerel corresponds to one nucleus decaying per second. Realizing the becquerel is achieved by the primary and secondary methods, depending on the following characteristics of the ionizing radiation: energy (from 1 keV to 7.5 MeV), type of radiation (alpha-, beta- particles, gamma-radiation, and X-rays), activity level (from 100 mBq to 70 GBq), decay properties (pure beta-decay, electron capture, single- or multi- photons emitted per nucleus decay). The national standard comprises primary (TDCR instrument, 4π β-γ coincidences proportional counter) and secondary (radionuclide calibrators “Fidelis” and Capintec 15R, the gamma-ray spectrometer) standards.

By applying primary methods, the following radionuclides are standardized: 3H, 14C, 36Cl, 55Fe, 60Co, 63Ni, 90Sr, 90Y, 99Tc, 129I, 152Eu. These measurements are traceable to FTMC itself.

The radionuclide calibrators are traceable to the Czech Metrology Institute (CMI) via the intercomparisons (EURAMET Projects Nos. 1243 and. 1437) for the radionuclides used in nuclear medicine: 18F, 67Ga, 99mTc, 111In, 123I, 125I, 131I, 201Tl, 223Ra, as well as for 137Cs.

IRML disseminates cost-effective measurement infrastructure to Lithuanian laboratories by organizing comparisons.