MRI: Track 1 Development of Large Optic Crystalline Coating Characterization Instrument (LOCCCI) for Gravitational Wave Detectors

MRI：用于引力波探测器的大型光学晶体涂层表征仪器 (LOCCCI) 的第一轨开发

• 批准号: 2320711
• 负责人: Steven Penn
• 金额: $ 107.75万
• 依托单位: Hobart and William Smith Colleges
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2320711&HistoricalAwards=false
• 关键词: MRI; Track; Development; Large; Optic

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. "Gravitational wave astrophysics is one of the most exciting frontiers in science.” states the National Academy of Sciences Decadal Survey (2020). This award will help achieve a key advancement in sensitivity for gravitational wave detectors and help resolve a noise source that has limited the field for the past two decades. Since 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) has detected over 90 events, including the inspiral and coalescence of binary neutron star and binary black hole systems. The most recent improvements to the detector promise new observations on a weekly basis. Nevertheless, LIGO’s sensitivity remains limited by coating thermal noise (CTN). The research funded by this award will enable the development of crystalline mirror coatings, which could reduce CTN by a factor of 10 compared to the current mirror coatings. This significant advancement in sensitivity will allow the detection of many more events at much higher sensitivity. Gravitational wave observations have informed and inspired a broad range of astronomers, physicists, students, and the general public. Many people are intrigued by black hole and neutron star observations and their fascination helps raise the public’s scientific awareness. This award will train undergraduate and graduate students with skills that can be applied to research and to technical areas in the broader economy. The team will continue to work hard providing these opportunities to groups that have been historically disenfranchised. Finally, the knowledge gained in this research will advance the areas of gravitational wave astrophysics, precision optics, and the materials science of low-dissipation materials.Mirror coating thermal noise (CTN) limits the sensitivity of current interferometric gravitational wave detectors in the central frequency band (the region of highest sensitivity). The current mirror coating technology of ion beam sputtered (IBS) amorphous oxides, which is used on all current gravitational wave detectors has, over the past 15 years, seen only modest gains in reducing the elastic loss that generates CTN. Fortunately, crystalline GaAs/AlGaAs coatings (hereafter AlGaAs coatings) meet LIGO’s stringent optical requirements and have a CTN estimated to be 10 times lower than the current Advanced LIGO coatings. This gain in sensitivity will generate a dramatic jump in event rate, which increases as the cube of the sensitivity range. It will also allow nearby events to be observed with very high signal-to-noise ratio, which may provide insights into the structure of neutron stars and additional tests of general relativity. Finally, crystalline coatings exceed the requirements for all planned future gravitational wave detectors. Thus, this award funds an advancement in instrumentation that will benefit the field for decades. However, challenges remain as AlGaAs coatings are birefringent, experience crystal defects, and have only been made in small diameters. This award will fund the LOCCCI instrument that will enable the development of low-noise, large-diameter, crystalline coatings for gravitational wave detectors. The LOCCCI instrument will be initially used to test these coatings at large diameters (20 cm) for birefringence noise, crystal defect densities, and surface uniformity. This investigation will then inform manufacturing improvements and ultimately justify the development of the 30 cm coatings that will be deployed in the detectors. This instrument will also test that the production coatings conform to design specifications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持相对论和相对论天体物理学的研究，并解决了美国国家科学基金会“宇宙之窗”大理念的优先领域“美国国家科学院十年调查指出，引力波天体物理学是最令人兴奋的科学前沿之一。” （2020）。该奖项将有助于实现引力波探测器灵敏度的关键进步，并有助于解决过去二十年以来限制该领域的噪声源。 2015 年，激光干涉仪引力波天文台 (LIGO) 已经探测到了 90 多个事件，包括双中子星和双黑洞系统的吸入和合并，探测器的最新改进有望每周都有新的观测结果。 LIGO 的灵敏度仍然受到涂层热噪声 (CTN) 的限制，该奖项资助的研究将有助于开发晶体镜涂层，与目前的涂层相比，这可以将 CTN 降低 10 倍。灵敏度的显着进步将允许以更高的灵敏度探测到更多事件。引力波观测已经为广大天文学家、物理学家、学生和公众带来了信息和启发。许多人对黑洞很感兴趣。中子星观测及其吸引力有助于提高公众的科学意识。该奖项将培养本科生和研究生，使其具备可应用于更广泛经济领域的研究和技术领域的技能。组最后，这项研究中获得的知识将推动引力波天体物理学、精密光学和低耗散材料的材料科学领域的发展。镜面涂层热噪声（CTN）限制了当前干涉引力波的灵敏度。中心频段（灵敏度最高的区域）探测器采用离子束溅射（IBS）非晶氧化物的电流镜涂层技术，用于所有电流。在过去的 15 年中，引力波探测器在减少产生 CTN 的弹性损失方面仅取得了一定的进展，幸运的是，晶体 GaAs/AlGaAs 涂层（以下简称 AlGaAs 涂层）满足 LIGO 严格的光学要求，并且其 CTN 估计为 10 倍。低于当前先进的 LIGO 涂层，这种灵敏度的提高将导致事件发生率急剧上升，并且随着灵敏度范围的三次方增加，它还允许以非常高的速度观测到附近的事件。最后，晶体涂层超出了所有计划的未来引力波探测器的要求，因此，该奖项将资助仪器的进步。然而，挑战仍然存在，因为 AlGaAs 涂层具有双折射性，存在晶体缺陷，并且只能制成小直径。该奖项将资助 LOCCCI 仪器的开发。用于引力波探测器的低噪声、大直径结晶涂层将首先用于测试这些大直径（20 厘米）涂层的双折射噪声、晶体缺陷密度和表面均匀性。该仪器还将测试生产涂层是否符合设计规范。该奖项由 NSF 法定授予。使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。