Thermal Noise in Test Masses and Suspensions for Gravitational Wave Interferometers

引力波干涉仪测试质量和悬浮液中的热噪声

• 批准号: 9602157
• 负责人: Peter Saulson
• 金额: $ 68.92万
• 依托单位: Syracuse University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-15 至 2000-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9602157&HistoricalAwards=false
• 关键词: Thermal; Noise; Test; Masses; Suspensions

According to the Fluctuation-Dissipation Theorem, thermal noise arises from any mechanism that dissipates mechanical energy. This means that a gravitational wave interferometer test mass and its suspension will work better, the lower is the level of dissipation. The Syracuse group will carry out studies of various test mass and suspension designs, characterizing them by their dissipation levels. One means of doing this is to measure the quality factors of the various mechanical resonances in the system. A novel method, newly developed by the Syracuse group, involves careful measurement of the response of the system after a steady stress has been released. Both methods will be employed in the search for the best ways to build and suspend test masses for LIGO. In order for the search for gravitational waves to succeed, it is necessary that detectors be free from disturbing influences that can mimic or mask the weak gravitational wave signal. Thermal noise, also known as Brownian motion, is among the noise sources most in need of reduction. The aim of the research program of the Syracuse University group is to understand the sources of thermal noise in interferometric detectors of gravitational waves (such as those of the LIGO Project), and to thereby learn ways of minimizing its strength. In addition to its main goal of improving the performance of LIGO and other gravitational wave detectors, this work may stimulate progress in understanding the structure of noncrystalline solids, such as the fused silica from which test masses are made.

根据涨落耗散定理，热噪声产生于任何耗散机械能的机制。 这意味着引力波干涉仪测试质量和它的悬浮将工作得更好，耗散水平越低。 锡拉丘兹小组将对各种试验质量和悬挂设计进行研究，并通过耗散水平来表征它们。 这样做的一种方法是测量系统中各种机械谐振的品质因数。 锡拉丘兹研究小组新开发的一种新方法涉及到在稳定应力释放后仔细测量系统的响应。 这两种方法都将用于寻找为LIGO构建和悬挂测试质量的最佳方法。 为了成功地寻找引力波，探测器必须不受干扰的影响，这些干扰可能会模仿或掩盖微弱的引力波信号。 热噪声，也称为布朗运动，是最需要降低的噪声源之一。 锡拉丘兹大学小组的研究计划的目的是了解引力波干涉仪探测器（如LIGO项目）中热噪声的来源，从而学习如何最大限度地减少其强度。 除了提高LIGO和其他引力波探测器的性能外，这项工作还可能促进对非晶体固体结构的理解，例如制造测试质量的熔融石英。