Dosimetry characteristics of coupled fast-thermal-core HERBE

The 'HERBE' is new coupled fast-thermal core, designed in 1991, at the 'RB' reactor in the 'Vinca' Institute. It is used for verification of designed oriented computer codes developed in the Institute, training and sample irradiation in fast neutron field. For the last purpose a vertical experimental channel (VCH) is placed in the central axis of the fast core. Neutron spectrum in the center of the VCH is calculated in 44 energy groups. Space distributions of two energy group neutron flux in the 'HERBE' are measured using gold foils and converted into the neutron absorbed dose using group flux-dose conversion factors. Gamma absorption doses in the air in the center of the VCH are measured using calibrated small ionization chamber filed with air. Determined dose rates are related to the reactor power. The first preliminary irradiations of silicon diodes in the center of the VCH of the 'HERBE' fast core are carried out in 1994 and 1995. This paper describes calculation methods and measurement techniques applied to determination of the irradiation performance and dosimetry characteristics of the 'HERBE' system.