An RUI Research Proposal on Minimizing Thermal Noise in Advanced LIGO Test Mass Optics and Exploring Bilinear Noise in Initial LIGO Data

RUI 关于最小化先进 LIGO 测试质量光学器件中的热噪声和探索初始 LIGO 数据中的双线性噪声的研究提案

• 批准号: 0355118
• 负责人: Steven Penn
• 金额: $ 30万
• 依托单位: Hobart and William Smith Colleges
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0355118&HistoricalAwards=false
• 关键词: RUI; Research; Proposal; Minimizing; Thermal

This research project will focus primarily on understanding and reducing the mechanical loss in fused silica. Methods of reducing the mechanical loss in large, polished, fused silica optics through careful annealing in inert gas and vacuum will be explored. This technique has already proven successful on small, flame-drawn samples, and is expected to benefit larger samples as well. In addition, a theoretical model for the mechanical loss in fused silica will be developed in collaboration with other LIGO thermal noise researchers . Such a model would greatly aid our understanding of the fundamental loss mechanisms and may provide guidance as to how this loss might be further reduced. Finally, development will continue on a bicoherence data monitor, which is a robust method for separating bilinear noise, burst events, and chirp events from a large background of Gaussian noise.This research on fused silica holds a great deal of promise for Advanced LIGO. The PI has previously demonstrated that annealing can reduce the mechanical loss in fused silica to a level equal to that of sapphire, the other material proposed for Advanced LIGO optics and better than the requirements for Advanced LIGO. The benefits of using silica include excellent optical qualities and greater experience as an optical material. As the PI has previously shown, the loss in fused silica, when minimized, is entirely in the surface, at least for the geometries measured thus far. In other words, the loss decreases as the size of the optic increases. Therefore it is expected that large optics, when properly annealed, should, despite being polished, have a mechanical loss below the Advanced LIGO requirements. Lowering the thermal noise in the test masses will increase LIGO's astronomical reach in its most sensitive frequency band and enhance the probability for detection and study of gravitational wave events.

该研究项目将主要集中在了解和减少熔融石英的机械损失。将探讨通过在惰性气体和真空中仔细退火来减少大型抛光熔融石英光学器件的机械损耗的方法。这种技术已经在小的火焰拉伸样品上证明是成功的，预计也将有利于更大的样品。此外，将与其他LIGO热噪声研究人员合作开发熔融石英中机械损耗的理论模型。这样一个模型将极大地帮助我们理解基本的损失机制，并可能为如何进一步减少这种损失提供指导。最后，将继续发展双相干数据监测器，这是一个强大的方法分离双线性噪声，突发事件，啁啾事件从一个大的背景高斯noise.This研究熔融石英举行了大量的承诺先进LIGO。 PI之前已经证明，退火可以将熔融石英的机械损耗降低到与蓝宝石相同的水平，蓝宝石是先进LIGO光学器件的另一种材料，并且优于先进LIGO的要求。使用二氧化硅的好处包括优异的光学质量和作为光学材料的丰富经验。如PI先前所示，熔融石英的损耗在最小化时完全在表面中，至少对于迄今为止测量的几何形状而言。换句话说，损耗随着光学器件尺寸的增加而减小。因此，预计大型光学器件在适当退火时，尽管经过抛光，但其机械损耗应低于Advanced LIGO要求。降低测试质量中的热噪声将增加LIGO在其最敏感频段的天文范围，并提高探测和研究引力波事件的可能性。