 The use of mesoprosilica films for producing and studying positronium, P.S., atoms has become increasingly important in recent years due to their ability to cool and confine P.S., allowing for precise spectroscopy and anti-hydrogen production. The cooling process involves ejecting P.S. atoms from the bulk material into internal voids, where they rapidly cool via wall collisions until thermalization occurs or quantum confinement reached. Emission into vacuum takes approximately 10 nanoseconds when the incident positron beam energy is 5 keV. The observed dependence of P.S. emission time on positron implantation energy supports the idea that quantum confined P.S. does not sample all available pore volume. This article was authored by Adela, B.S. Cooper, T.E. Wall, and others.