2011 Article Detectors ICNCT14 Physics

Effect of the calibration in water and the build-up cap on the Mg(Ar) ionization chamber measurements

Applied Radiation and Isotopes, 2011

Authors:   H. Koivunoro,H. Hyvönen,J. Uusi-Simola,I. Jokelainen,A. Kosunen,M. Kortesniemi,T. Seppälä,I. Auterinen,S. Savolainen,
Journal: Applied Radiation and Isotopes
Abstract: Magnesium-walled argon gas flow ionization chamber (Mg(Ar)) is used for photon dose measurements in the epithermal neutron beam of FiR 1 reactor in Finland. In this study, the photon dose measurements were re-evaluated against calculations applying a new chamber calibration factor defined in water instead of in air. Also, effect of the build-up cap on the measurements was investigated. The new calibration factor provides improved agreement between measured and calculated photon dose. Use of the build-up cap does not affect the measured signal in water in neutron beam.