The Stanford Advanced Gravitational Wave Detector Research Program

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。该奖项扩展了斯坦福大学LIGO小组正在进行的高级引力波探测器计划，以解决高级LIGO的风险缓解问题，并为增强高级LIGO以提高观测灵敏度提供研究。特别是，研究将集中在改进的光学涂层，静电充电的控制，以及地震隔震系统的倾斜传感。(1)该小组将包括地壳中无定形氧化物的核磁共振光谱学和拉曼光谱学方面的新专业知识，以获得有关选定涂层材料中键配置的微观结构信息。这些涂层中的机械噪声引起的热噪声将限制先进LIGO以外的任何未来干涉仪的灵敏度。因此，这项研究的目标是了解机械损失机制的物理学，以便我们能够向LIGO科学合作(LSC)中的其他研究人员提供关于减轻这种噪声源的信息。(2)该小组还将与LSC合作，为Advanced LIGO制定收费管理系统的要求。标度参数将被用来预测潜在的静电电荷积累可能占主导地位的来源。数值计算将确定它们的优先顺序，并确定哪些值得对其对噪声预算的贡献进行完全有限元建模。缓解技术的发展将包括研究碱性离子内扩散，以实现弱导电的测试质量表面，使虚假表面电荷松弛到等电势，而不影响光学和机械涂层损失。将评估局部UV LED传导通道，以允许测试质量和接地框架之间的无源电荷平衡，而不会损坏UV敏感光学涂层。3)将开始研究开发改进的倾斜传感器，以提高先进LIGO主动隔震系统的性能，该系统使用外部激励的被动环形光学陀螺仪，可用于直接测量地面旋转并改善隔震系统的性能，从而提高先进LIGO的运行可靠性。这项研究计划包括许多学科的参与，包括机械、电气和控制工程师、物理学家和材料研究人员。这种多学科努力的性质使其成为培养研究生的理想选择。鼓励高中生和大学本科生参与这些项目，将研究和教育结合起来。此外，该计划将开发技术并将其转化为商业流。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This award extends the Stanford LIGO group's ongoing program on advanced gravitational wave detectors to address risk mitigation for Advanced LIGO and to provide research for enhancements to Advanced LIGO to increase observatory sensitivity. In particular, research will focus on improved optical coatings, control of electrostatic charging, and tilt sensing for the seismic isolation system. (1) The team will include new expertise in NMR spectroscopy of amorphous oxides in the earth's crust and Raman spectroscopy, to obtain micro-structural information on bond configurations in the selected coating materials. Thermal noise due to mechanical noise in these coatings will limit the sensitivity of any future interferometer beyond Advanced LIGO. Thus the goal of this research is to understand the physics of the mechanical loss mechanisms so that we can inform other researchers in the LIGO Scientific Collaboration (LSC) on the mitigation of this noise source. (2) The team will also work with the LSC to develop requirements for a charge management system for Advanced LIGO. Scaling arguments will be used to predict which sources of potential electrostatic charge accumulations might be dominant. Numerical calculations will prioritize them and identify those that merit full finite-element modelling of their contribution to the noise budget. Development of mitigation techniques will include research on alkali ion in-diffusion to achieve weakly conducting test mass surfaces that will allow spurious surface charges to relax to equipotentials without impacting the optical and mechanical coating losses. A localized UV LED conduction channel to allow passive charge equilibration between the test mass and the grounded frame without damage to the UV-sensitive optical coatings will be evaluated. 3) Research will be initiated to develop improved tilt sensors for increasing the performance of the active seismic isolation systems in Advanced LIGO using externally excited, passive ring optical gyroscopes which could be used to directly measure the ground rotations and improve the performance of the isolation systems which would lead to improved operational reliability of Advanced LIGO. This research program includes participation from many disciplines including mechanical, electrical and control engineers, physicists and materials researchers. The nature of this multidisciplinary effort makes it ideal for training graduate students. High school students and university undergraduates are encouraged to participate in these projects, integrating research and education. In addition, the program will develop and transfer technologies to the commercial stream.