Inertial Sensors for Ground Based Gravitational Wave Detectors

隔震研究的目标是继续伯明翰大学的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，这是一种由一个证明质量组成的装置，该证明质量软挂在一个平台上（与地面相连），该平台在其谐振频率以上保持惯性。6D对6个自由度（3个平移和3个旋转）的地面运动很敏感，这是通过干涉读数检测到的。目前的隔离系统和地震仪有一个固有的问题，倾斜到水平耦合，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。这项工作将有助于提高aLIGO探测器站点的隔震性能，以及未来升级到探测低至5Hz的引力波（LIGO-LF）。我的研究将包括对这个系统的动力学建模，并研究控制机制来稳定悬浮的质量。研究的另一个方面将是设计和建造一个六轴舞台平台。这将类似于先进LIGO （aLIGO）中使用的惯性隔震（ISI）平台。最终的目标是创建系统的原型。旋转传感器将有可能成为基于受激布里渊散射和利用Sagnac效应色散的耳语廊模式光学陀螺仪。光学陀螺仪的优点是不会因摩擦而产生损耗，因此与机械陀螺仪相比，光学陀螺仪的可靠性更高。该项目将包括装置的建造和实验测试其灵敏度。检测地面旋转或悬浮质量的旋转漂移可能是该装置的应用。其他应用将是空间仪器的位置传感。然而，陀螺仪也可能有商业用途（如导航），因为它将是一个小的（目前未指定）尺寸，可以潜在地部署在许多系统作为售后附件。

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.