Laser Cooling of Antihydrogen for Fundamental Symmetry Tests with ALPHA at CERN

这项RTI建议将直接和实质性地支持基于CERN的阿尔法(反氢激光物理装置)合作的研究计划。具体地说，它直接支持完全由加拿大牵头的反氢激光冷却倡议的设备。阿尔法是一个国际项目，其目标是测量和比较“反氢”的某些性质和普通氢的性质。反氢是中性反物质最简单的原子形式。阿尔法将直接测试和挑战关于物质和反物质之间的异同(对称性)的基本理论，这个问题可以说是物理学中最大的悬而未决的问题之一。近年来，阿尔法在追求其主要目标方面取得了许多重大和高调的里程碑，包括：稳定地(2010年)和长期(2011年)捕获中性反物质，并证明了捕获反氢的微波原理研究(2012年)。 在实现了反氢捕获和第一次光谱分析的里程碑之后，阿尔法经历了一次重大升级。新的仪器(阿尔法-2)，由加拿大的重大贡献建造，提供了激光获取捕获的反氢的途径，以及改善了精密光谱分析的磁场均匀度。通过施加辐射压力冷却反氢原子将提供被捕获的反氢的冷而致密的样品，这是实现反氢光谱最终精度的必要步骤。然而，这种工艺所需的激光光源的开发在技术上具有挑战性。在过去的几年里，加拿大阿尔法的激光小组已经开发了一个全固态莱曼-阿尔法激光系统，并将该系统安装在欧洲核子研究中心，并在反氢囚禁室内成功地产生了121.5 nm的莱曼-阿尔法激光。在这些重要技术里程碑的基础上，这笔RTI赠款将提供关键设备，使反氢激光冷却最终成为可能，这是该领域多年来的梦想。这笔赠款将支持购买高功率、窄线宽抽运激光器和光学组件，以增加莱曼-阿尔法光的能量。这些仪器将帮助实现世界上第一次反氢激光冷却，并为实现物质和反物质之间的精确对称性测试这一雄心勃勃的目标铺平道路。

This RTI proposal will directly and substantively support the research program of the CERN-based ALPHA (Antihydrogen Laser Physics Apparatus) Collaboration. Specifically, it directly supports equipment for the entirely Canadian-led initiative on laser cooling of antihydrogen. ALPHA is an international project whose goal is to measure and compare certain properties of 'antihydrogen' - the simplest atomic form of neutral antimatter - with those of ordinary hydrogen. ALPHA will directly test and challenge fundamental theories with regard to the similarities and differences ('symmetries') between matter and antimatter, an issue that is arguably one of the greatest unsolved problems in physics. In recent years, ALPHA has achieved many significant and high profile milestones in its pursuit of its primary goal, including: stable (2010) and long term (2011) trapping of neutral antimatter, and proof of principle microwave studies of trapped antihydrogen (2012). Having achieved its milestones of antihydrogen trapping and the first spectroscopy, ALPHA has undergone a major upgrade. The new apparatus (ALPHA-2), constructed with significant Canadian contributions, provides laser access to trapped antihydrogen, as well as improved magnetic field homogeneity for precision spectroscopy. Cooling of antihydrogen atoms via the application of radiation pressure will provide a cold and dense sample of trapped antihydrogen, and is a necessary step for achieving the ultimate precision in antihydrogen spectroscopy. However, development of the laser source required for such process has been technically challenging. In the past few years, the laser group in ALPHA-Canada has developed an all solid state Lyman-alpha laser system, installed the system at CERN, and successfully generated Lyman-alpha light at 121.5 nm at the antihydrogen trap chamber. Building on these important technical milestones, this RTI grant will provide critical equipment to make laser cooling of antihydrogen finally possible, which has been a dream for those in the field for many years. This grant will support the purchase of a high-power, narrow-linewidth pump laser and optical components in order to increase the energy of the Lyman-alpha light. These instruments will help enable the world’s first laser cooling of antihydrogen, and pave the path towards the ambitious goal of precision symmetry tests between matter and antimatter.