POSITRON-ANNIHILATION IN TEKTITE AND HYALITE

Positron lifetime spectra as well as one-dimensional angular distribut ions of photons coming from the two-photon annihilation of an electron -positron pair were measured at room temperature for samples of natura l tektite and hyalite. The data were used for estimation of positroniu m characteristics in the specimens. The characteristics were analysed in terms of parameters of pores trapping the positronium atoms before their decay. In the analysis two models of the traps were taken into a ccount, i.e. the square potential wells of spherical symmetry with bar riers of finite and infinite heights. It was found that the linear dim ensions of the pores resulting from these two-trap models are almost t he same and they are of the order of 1 nm.