Formation of a Dense Gas of Positronium

浓密正电子气体的形成

• 批准号: 0140382
• 负责人: Allen Mills
• 金额: $ 37.45万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140382&HistoricalAwards=false
• 关键词: Formation; Dense; Gas; Positronium

This effort is the beginning of a multi-step project that has the long-term goal of demonstrating the existence of an annihilation photon laser based on annihilation radiation from positronium in a dense gas. The specific goals of the first three years are: 1) Compress a cold, spin-aligned, non-neutral plasma of positrons trapped in a magnetic field to near the Brillouin limit. Extract the positrons and focus them to a microscopic spot on a sample in a short time pulse; 2) Demonstrate the existence of a high positron surface density by forming and observing the di-positronium molecule, Ps2. The density dependence of the Ps2 yield may be interpreted to give the binding energy of Ps2 relative to two free Ps atoms and the accommodation or sticking coefficient SPs2 for Ps2 absorption at the surface; and 3) Form a gas of high-density triplet Ps within a cavity. The research efforts will be accompanied by an educational effort in which undergraduate students will be involved in part time work creating demonstration experiments suitable for encouraging high school students to work in scientific fields and creating a high school level interactive internet web site on "Antimatter" to eventually permit remote real time participation in demonstration experiments.

这项工作是一个多步骤项目的开始，该项目的长期目标是证明基于稠密气体中正电子湮没辐射的湮没光子激光的存在。头三年的具体目标是：1)将捕获在磁场中的自旋排列的非中性正电子等离子体压缩到布里渊极限附近。提取正电子，并在短时间脉冲内将它们聚焦到样品上的微观斑点；2)通过形成和观察双正电子分子PS2，证明存在高正电子表面密度。PS2产额的密度依赖关系可以解释为PS2相对于两个自由Ps原子的结合能和PS2在表面吸收的调节或粘着系数Sps2；3)在腔内形成高密度三重态Ps气体。研究工作将伴随着一项教育工作，本科生将参与兼职工作，创建适合于鼓励高中生在科学领域工作的演示实验，并创建一个高中级别的互动互联网网站，最终允许远程实时参与演示实验。