title: (56)Mn, (60)Co, (18)F and (22)Na activity measurements by coincidence technique at VNIIM.
abstract: For modernization of the Russian national activity standard at the Ionizing Radiation Department of the D.I. Mendeleyev Institute for Metrology, a prototype 4π(LS)-γ(NaI) coincidence arrangement was created, and applied to the standardization of long-lived (60)Co and (22)Na and short-lived (56)Mn and (18)F. Efficiency variation was performed using "grey filters", high voltage variation and variation of low threshold. The main metrological characteristics of the setup were determined: long-term stability, background, dead time, resolution time and temperature dependence. The results obtained have practical applications. The (18)F solution with well-known activity is required for calibration of ionizing chamber used in nuclear medicine. The (56)Mn is used for calibration of manganese bath equipment used in neutron laboratory. The results obtained are in good agreement with 4πγ(NaI)-counting and 4πβ(PC)-γ(NaI) methods of Russian national radioactivity standard. The combined uncertainty (k=2) of results was estimated in the range 1-2%.
authors: D.I. Mendeleyev Institute for Metrology (VNIIM), 19 Moskovsky Prospect, St. Petersburg 198005, Russia. Electronic address: tee@vniim.ru.
authors: Tereshchenko
authors: T
authors: Evgeny
authors: D.I. Mendeleyev Institute for Metrology (VNIIM), 19 Moskovsky Prospect, St. Petersburg 198005, Russia.
authors: Moiseev
authors: M
authors: Nikolay
authors: D.I. Mendeleyev Institute for Metrology (VNIIM), 19 Moskovsky Prospect, St. Petersburg 198005, Russia.
authors: Kolodka
authors: K
authors: Alexander
keywords: Cherenkov-gamma coincidences; Efficiency extrapolation; Positron-annihilation photons coincidences