Positron Annihilation Ratio Spectroscopy Applied to Positronium Formation Studies

A Positron Annihilation of Radiation Spectrometer (PsARS) was developed and characterized. PsARS spectroscopy as well as digital Positron Annihilation Lifetime Spectroscopy (PALS) was applied to measure positronium formation on gold manoparticles deposited through an evaporative method onto a thin capillary tube. This gold coated capillary tube was designed to be used for positronium lifetime studies in local electric field experiments. High local electric fields can polarize a positron-electron pair, which may result in an extended lifetime of the positron. These fields may be created through the interaction of an external electric field with silver manoparticles deposited onto the surface of gold coated capillary tubes. The capability to control size and distribution of silver manoparticles on such a surface is demonstrated. PsARS analysis of potassium dodecahydrododecaborate (dodecaborate) solutions was also performed to verify positronic dodecaborate species as well as potential positronium quenching.