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Rocks, minerals, and powdered catalysts, not considered "typical" positron annihilation spectroscopy materials were included in these studies, to find the optimal way to characterize atypical materials by the most appropriate set of parameters in a well-defined environment. The positron annihilation spectroscopies: the Doppler broadening and positron lifetime were compared with other supplementary techniques to validate, interpret, and understand the results in different materials better. It was found that although rocks are heterogeneous mineral aggregates, some positron annihilation spectroscopy values were specific for various types of rocks, potential oil deposits, and their conditions; and quite different for opals due to Ps formation there; moreover in order to characterize properly samples with small mass and density (catalytic powders), their measuring geometry, matrix effect, and set of operational parameters needed to be well-defined. [ABSTRACT FROM AUTHOR]

Abstract: Two techniques have recently been developed to quickly and easily apply positron annihilation spectroscopies to large structural components found in civil engineering, aviation, etc. In this paper, the authors discuss how to extend imaging capabilities to these new techniques, which will enable defect imaging similar to that obtained with positron micro-beams but at much larger sample sizes. Preliminary two-dimensional defect imaging results are presented from a highly damaged 30.5×30.5cm copper plate. [Copyright &y& Elsevier]