Positronium in Metal-Oxide Powders Studied with Age. The Age-Momentum Correlation Technique |
| B. Van Waeyenberge and Ch. Dauwe NUMAT, Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium |
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| For the first time positronium is investigated in fine powders of MgO and Al2O3 using age-momentum correlation technique based on a relativistic positron beam. The application of this technique for investigating the interaction of positronium with the grain surfaces is discussed and compared with other techniques. The previously reported interaction of the positronium with paramagnetic centres is further studied. A qualitative interpretation of the spectra is given. In the Al2O3 samples we found some unexpected behaviour of the conversion quenching of ortho-positronium at irradiation induced paramagnetic surface defect. |
| DOI: 10.12693/APhysPolA.100.707 PACS numbers: 36.10.Dr, 41.75.Fr, 78.70.Bj |