RUI: Low Energy Positronium Interactions with Atoms and Molecules in a Gas Environment

该实验研究计划的重点是了解正电子素（一个电子和一个正电子结合在一起的系统）与气体环境中的原子和/或分子之间的基本相互作用。这项研究的核心是一个新开发的动量相关装置，旨在观察正电子素的形成。该设备已经能够使用高纯锗（HPGe）探测器首次定量观察热能下的正电子素，展示了该技术前所未有的精度和范围。随着这项技术的强大，正电子素散射原子和/或分子的动量转移截面的测量将在更广泛的气体中进行测量，在更宽的能量范围内（低于6.8电子伏），并且比以前的任何实验都更精确。此外，它将以一种新的、更直接的方式对拾取湮没（电子和正电子衰变为伽马射线）直接敏感，从而对这一过程有新的见解。该计划的更广泛的影响涉及本科生教育以及生物系统的应用。

This experimental research program focuses on the understand of basic interactions between positronium (a system with one electron and one positron bound together) and atoms and/or molecules in a gas environment. At the heart of this research is a newly developed Age-Momentum Correlation apparatus designed to observe positronium formed. This apparatus has already enabled the first quantitative observation of positronium at thermal energies with a High-Purity Germenium (HPGe) detector, demonstrating an unprecedented precision and range for the technique. With the power of the technique firmly established, measurements of the momentum-transfer cross-section for positronium scattering off atoms and/or molecules will be measured in a wider variety of gases, over a broader energy range (below 6.8 electron volts), and with greater precision than any previous experiment. Furthermore, it will be directly sensitive to pick-off annihilation (the decay of the electron and positron into gamma rays) in a new and more direct way, allowing new insights into this process. The broader impact of the program involves undergraduate student education as well as applications to biological systems.