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Sample records for caldasite

  1. Development and Building of Radioactive Concrete Pads for calibration of the airborne and ground gamma-ray spectrometers, used in mineral exploration and hydrocarbons; Desenvolvimento e construcao de blocos de concreto radioativo para calibracao de espectrometros gama portateis e aerotransportados, utilizados em exploracao mineral e de hidrocarbonetos

    Energy Technology Data Exchange (ETDEWEB)

    Carlos, Dionisio Uendro

    2006-07-01

    Eight transportable calibration pads were built in to be used as concentration standards for portable and airborne gamma-ray spectrometers calibrations. The pads construction procedure is described in full detail. The pads, with dimensions of 1 m x 1 m x 0,30 m and masses between 593 kg and 673 kg were made radioactive by the addition of different amounts of k-feldspar, caldasite and monazitic sand to the concrete masses. The potassium, uranium and thorium concentration vary significantly in the pads, reaching maximum values of 5,7% of K, 45,6 ppm eU and 137 ppm eTh. The distribution of the gamma radiation flux from the pads surfaces and the heterogeneity magnitudes of the radioactive elements concentration were experimentally established. An example of gamma-ray spectrometer calibration is presented. (author)