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Competitive positron and positronium trapping in porous media
Kajcsos, Zs.; Liszkay, L.; Duplâtre, G.; Lázár, K.; Lohonyai, L.; Varga, L.; Gordo, P. M.; Lima, A. P. de; Gil, C. Lopes de; Marques, M. F. FerreiraPositron annihilation acquired acceptance for structural investigation of solids but results in porous media--where positron lifetime spectroscopy (LT) reveals substantial Ps formation--were ambiguous. Data on zeolites lead to the conclusion that Ps trapping in competing "extended free volume" sites, inhomogeneous regions and grain boundaries occurs. Furthermore, positron trapping must also be considered. Syste...
Positron and positronium annihilation patterns in zeolites and bulk ceramics
Kajcsos, Zs.; Kosanovic', C.; Liszkay, L.; Major, P.; Lohonyai, L.; Zalán, P.; Lázár, K.; Bosnar, S.; Subotic', B.; Bosnar, D.; Havancsák, K.Positron lifetime (LT) measurements have revealed that in porous media the annihilation pattern is probably dominated by a near-saturation level trapping both for the positron and the positronium as well, which masks the contribution from the ldquofree annihilationrdquo, i.e., annihilation from delocalised positrons. In this work we compare positron lifetime spectra of crystalline zeolites with bulk ceramic mat...
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