Airborne Gamma-Spectrometry in Switzerland

摘要

Airborne gamma-spectrometry is able to obtain fast radiological information over largeareas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss NationalEmergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equippedwith four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time dataevaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) andthe Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometrysystem is validated in annual exercises of one week duration. Data from 2005 and 2006 exercisesare represented in maps of ~(137)Csactivity concentration for two towns located in southern andwestern Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated foran area with four different types of nuclear installations. The intercomparison between airbornegamma-spectrometry and ground measurements showed good agreement between both methods.