Analysis of the potential for sub-eV Ps beams

Understanding the interactions of Ps at low energies has challenged researchers due to the inability to create Ps near thermal energies in a directed fashion. As a result, previous attempts to understand interactions such as the scattering cross-section (σ) between Ps and other atoms have relied on indirect methods. Examples are the measurements of the thermalization rate of Ps in a gas environment or lifetime measurements in various systems. In analyzing the pore size of certain nanotube materials we have observed 3–10% of incident positrons form long lived Ps within the sample. Due to the alignment of these tubes we expect Ps emitted from them to be highly directional. By focusing a time-tagged positron beam on these samples we will use the resulting directional Ps emitted at near thermal energies for various scattering experiments.