Low Noise Suspensions and Readout Systems for Improving Advanced LIGO

用于改进先进 LIGO 的低噪声悬架和读出系统

• 批准号: 1305863
• 负责人: Rana Adhikari
• 金额: $ 47万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1305863&HistoricalAwards=false
• 关键词: Low; Noise; Suspensions; Readout; Systems

This is a collaborative research program between Vladimir Braginsky's Moscow State University (MSU) group and the Laser Interferometer Gravitational-Wave Observatory (LIGO) Laboratory. It focuses on two types of enhancements under consideration for Advanced LIGO: the use of crystalline silicon for the interferometer mirrors to reduce thermal noise, and quantum measurement techniques that can give sensitivities beyond the current limits due to quantum (shot) noise. Crystalline silicon is known to have excellent mechanical properties and has a minimum in its thermal expansion near 120 K. Operation at this point would minimize thermal noise. However, many aspects are not yet well enough understood for large scale application. Under this grant, we explore techniques for fabricating silicon ribbons for a silicon test mass suspension operating at 120 K, measure dissipation in silicon ribbon suspensions, and to find ways of minimization dissipation and thermal noise in the silicon suspensions. We investigate optical losses and other poorly measured thermal, mechanical and optical properties of pure high-ohmic crystalline silicon and other possible candidate materials for test masses from room to liquid nitrogen temperatures. Finally we analyze sources of noise in crystalline coatings applied to silicon test masses. The other main limitation to the sensitivity of Advanced LIGO will be quantum (shot) noise. We also continue the investigation of new topologies and measurement schemes for laser gravitational wave detectors, relevant to both Enhanced Advanced LIGO and beyond, and allowing us to suppress quantum noise and to relax requirements for the circulating optical power. The results of this work have a number of impacts. The most direct is that the techniques developed can be used to make gravitational wave detectors more sensitive, and thus help derive more information about the astrophysical phenomena that cause gravitational waves. Understanding the unusual conditions that create gravitational waves improves our understanding of violent processes that shape our universe exciting and inspiring students and the public. More broadly, the same techniques which are developed under this research can be used in a number of precision measurement applications in science and engineering. These include reducing noise in precison frequency reference standards to produce more accurate clocks, making quantum cryptography and quantum computing more feasible, improved tests of fundamental assumptions about space and matter, and ... finally, a major goal of this work is to foster closer collaboration on peaceful research between Russian and US scientists. This promotes better understanding between the scientific communities in these two super-powers.

这是弗拉基米尔·布拉金斯基（Vladimir Braginsky）的莫斯科州立大学（MSU）小组与激光干涉仪重力波体天文台（LIGO）实验室之间的合作研究计划。 它重点介绍了高级Ligo正在考虑的两种类型的增强功能：用于干涉仪镜的使用结晶硅以减少热噪声，以及可以使由于量子（射击）噪声引起的敏感性超出当前限制的量子测量技术。 众所周知，晶硅具有出色的机械性能，其热膨胀在120 K附近的热膨胀最小。此时的操作将最小化热噪声。 但是，许多方面尚未足够理解用于大规模应用。 在此赠款下，我们探索用于制造硅丝带的技术，用于在120 K下运行的硅测试质量悬浮液，测量硅色带悬浮液中的耗散，并找到最小化耗散和硅悬架中的热噪声的方法。 我们研究了光损失以及其他测量较差的高含量晶体硅和其他可能的候选材料的热，机械和光学特性，用于从房间到液态氮气温度的测试质量。 最后，我们分析了应用于硅测试量的晶体涂层中的噪声来源。 高级ligo灵敏度的另一个主要限制将是量子（镜头）噪声。 我们还将继续研究与增强的晚期Ligo及其他地区有关的激光引力波检测器的新拓扑和测量方案，并允许我们抑制量子噪声并放松循环光功能的要求。 这项工作的结果有许多影响。 最直接的是，开发的技术可用于使引力波检测器更加敏感，从而有助于获取有关引起引力波的天体物理现象的更多信息。 了解创造引力浪潮的异常条件可以提高我们对塑造我们宇宙令人兴奋和鼓舞人心的学生和公众的暴力过程的理解。 更广泛地说，这项研究中开发的相同技术可以用于科学和工程的许多精确测量应用中。 其中包括减少促进频率参考标准中的噪声，以产生更准确的时钟，使量子加密和量子计算更可行，改进了关于空间和物质的基本假设的测试，并且...最后，这项工作的主要目标是促进俄罗斯和美国科学家之间的和平研究更紧密的合作。这促进了这两个超级能力的科学社区之间的更好理解。