RUI: Investigation of suspended optics' motion of the LIGO detector and its influence on the detector's performance

该项目的科学目标是利用数值模拟和LIGO利文斯顿天文台（LLO）的实际数据分析激光干涉仪引力波（LIGO）探测器的性能。利用由加州理工学院LIGO实验室模拟小组开发的端到端（e2e）模拟包，将建立各种程序来模拟输入光学（IO），即位于激光源和干涉仪之间的光学链。这些程序将以地板运动和进入IO部分的激光束的电场作为输入，并计算光学器件的运动和IO输出光束的电场的结果。为使数值模拟切合实际，在LLO录得的实际信号将用作机械和光学输入。仿真的输出将与LLO与输入同时记录的相应信号进行比较。在确认有效性后，这些程序将被纳入SimLIGO，这是LIGO实验室模拟小组目前开发的用于模拟整个LIGO探测器的e2e程序。当前版本的SimLIGO没有配备IO的动态模型。利用得到的程序，将进行数值实验来研究锁损和底板运动对干涉仪性能的其他影响。东南路易斯安那大学本科生的参与是这个项目的重要组成部分。该项目的教育目标将通过两种广泛的方式实现：积极地让本科生参与研究，并在课堂上使用研究成果作为工具。激光干涉仪引力波天文台（LIGO）的目标是首次直接探测到引力波，并开始研究产生引力波的天文系统的特性。这个项目将在几个方面为LIGO做出贡献。开发的仿真程序可用于修改控制系统的设计，获得不能直接测量的子系统特性的间接测量，并为仿真程序的其他方面的开发提供信息。

The scientific objective of this project is to analyze the performance of the Laser Interferometer Gravitational-wave (LIGO) detector using numerical simulation and actual data available at the LIGO Livingston Observatory (LLO). Using the end-to-end (e2e) simulation package developed by the LIGO Laboratory simulation group at the California Institute of Technology, various programs will be built to simulate the input optics (IO), the chain of optics located between the laser source and the interferometer. These programs will take floor motions and the electric field of the laser beam entering the IO part as inputs, and compute the resultant motions of the optics and the electric field of the output beam from the IO. To make the numerical simulation realistic, actual signals recorded at LLO will be used for the mechanical and optical inputs. The output of the simulation will be compared with the corresponding signal recorded at LLO concurrently with the input. On confirming the validity, these programs will be incorporated into SimLIGO, the e2e program currently developed by the LIGO Laboratory simulation group to simulate the whole LIGO detector. The current version of SimLIGO is not equipped with a dynamic model of IO. With the resultant program, numerical experiments will be performed to study lock-loss and other effects of the floor motion on the interferometer performance. The involvement of Southeastern Louisiana University undergraduate students is an important element of this project. The educational objectives of this project will be realized in two broad ways: by actively involving undergraduate students as researchers and by using the products of the research as tools in the lecture classes. The goal of the Laser Interferometer Gravitational-wave Observatory (LIGO) is the first direct detection of gravitational waves and the initiation of their study to understand the properties of the astronomical systems that produce them. This project will contribute to LIGO in several ways. The developed simulation programs can be used to modify the design of the control systems, to obtain indirect measurements of properties of subsystems that cannot be measured directly, and to inform the development of other aspects of the simulation programs.