Vol. 33, Issue 1, pp. 7-12
Keywords
positron annihilation, positronium, porous glass, porosimetry
Abstract
Two Vycor glasses were investigated using PALS method. The model of pick-off annihilation in cylindrical free volume was applied to evaluate the pore radii. The o-Ps mean lifetime value in the pores changed from 6.5 to 40 ns in one glass, while from 13 to 51 ns in the other (softer) one. The determined pore radii, using a cylindrical shape model, were from 0.5 to 1.4 nm and from 0.7 to 1.6 nm, respectively.