[Standardization of a reference dosimeter system for radiotherapy in Switzerland]

The Swiss ordinance on radioprotection prescribes the periodic verification of the reference dosimeter systems for radiotherapy. The corresponding modalities were elaborated by an interdisciplinary collaboration of representatives of all concerned institutions. The modalities require in particular that the verifications are performed with the radiation qualities used in the hospitals. The verification concept is already realized for high energy photon radiation and for low and medium energy X-rays. The measurement capabilities for the verification with high energy electron beams are in preparation. The tasks to verify the reference dosimeter systems are divided between the Swiss Office of Metrology and Accreditation, METAS, and the Institut Universitaire de Radiophysique Appliquée, IRA. The corresponding metrological infrastructure and measurement capabilities of both institutes are presented. In particular, the traceability of the standards used for the verification to national and international primary standards and thus to the SI system of units is explained. The primary standards established and operated by METAS are briefly described.