Inertial Sensors for Ground Based Gravitational Wave Detectors

隔震研究旨在继续伯明翰大学的Conor Mow-Lowry博士和Denis Martynov博士的工作。他们提出了一种6D惯性隔离器，这是一种由柔和地悬挂在平台(连接到地面)上的验证质量组成的设备，该平台在其共振频率以上保持惯性。6D对通过干涉读数检测到的6个自由度(3个平移和3个转动)的地面运动很敏感。电流隔离系统和地震仪存在倾斜到水平耦合的固有问题，会影响输出信号。目标是测量所有自由度的平台运动，从而消除平移运动中的倾斜。这项工作将有助于改善aLIGO探测器地点的地震隔离，并有助于未来升级以探测低至5赫兹的引力波(LIGO-LF)。我的研究将包括对这个系统的动力学进行建模，并研究稳定悬浮质量的控制机制。研究的另一个方面是设计和建造一个六轴舞台平台。这将类似于高级LIGO(ALIGO)中使用的惯性地震隔离(ISI)平台。最终目标将是创建该系统的原型。旋转传感器将有可能成为一种基于受激布里渊散射和利用萨格纳克效应的色散的耳语廊式光学陀螺仪。光学陀螺仪的优点是不会因摩擦而损失，因此与机械陀螺仪相比，它们的可靠性更高。该项目将包括建造该装置并对其灵敏度进行实验测试。探测地面旋转或悬浮物的旋转漂移很可能是该设备的应用。其他应用将是空间仪器上的位置传感。然而，陀螺仪也可能有商业用途(如导航)，因为它将是一个小尺寸(目前未指明)，可能会部署在许多系统上作为售后附件。

The research for seismic isolation aims to continue on the work from Dr Conor Mow-Lowry and Dr Denis Martynov of the University of Birmingham. They have proposed a 6D inertial isolator which is a device that consists of a proof mass that is softly suspended from a platform (linked to the ground) which remains inertial above its resonant frequencies. 6D is sensitive to ground motion in 6 degrees of freedom (3 translational and 3 rotational) which are detected via interferometric readout. Current isolation systems and seismometers have an inherent issue with tilt-to-horizontal coupling, effecting the output signal. The goal is to measure the platform motion in all degrees of freedom, therefore removing the tilt from the translational motion. This work will be beneficial in improving the seismic isolation at the detector sites of aLIGO and future upgrades to detect gravitational waves down to 5Hz (LIGO-LF). My research will involve modelling the dynamics of this system and working on control mechanisms to stabilise the suspended mass. Another aspect of the research will be designing and constructing a 6-axis stage platform. This will be similar to the Inertial Seismic Isolation (ISI) platforms used in Advanced LIGO (aLIGO). The final goal would be to create a prototype of the system.The rotational sensor will potentially be a whispering gallery mode optical gyroscope based on stimulated Brillouin Scattering and dispersion using the Sagnac effect. An optical gyroscope has the benefit of no losses due to friction, thereby increasing their reliability compared to their mechanical counterparts. The project will involve construction of the device and experimentally testing its sensitivity. Detection of ground rotation or rotational drift of suspended masses will likely be the application of this device. Other applications will be position sensing on space instruments. However, the gyroscope may also have commercial uses (such as navigation) as it will be a small (currently unspecified) size which can potentially be deployed on many systems as an aftermarket attachment.