scope:

The report covers methods of specifying gamma-ray sources and the recommended basis for source specification. The report sets out specific recommendations relating to teletherapy sources, radiographic sources, and research and industrial irradiation sources. Report 18 also includes appendices on practical considerations in the design of a low-scattering measuring cell, primary and scattered radiation from typical sources and collimaters, and measurements of equipment conversion ratio. The report is concerned only with gamma-ray sources and only with those aspects of the specification of such sources, which relate to the quantity of radioactive material and the radiation emmited.