Experimental determination of the layout and the number of spherical radiation source assemblies in a gamma irradiation plant

Developed is the method for determining the position and number of spherical radiation sources assemblies in rod-type radiating elements of gamma plants. This method is based on the use of a coloured visual dosage indicator in the form of a film whose colour changes depending on the irradiation dose. The film has been irradiated for 40 min after which the length of a changed colour portion is measured, it corresponds to the active section of the irradiator tube. The calculational relationships are derived from the ''ball-in-tube'' geometry analysis. Analyzed is the redistribution of the cassettes with sources in the rod-type radiating elements of the installation performed by means of the overloading mechanism. The experiments performed have revealed that the reliability of the method and relationships derived as well as the validity of the overloading mechanism are rather good