Sensors for Low-Frequency Improvements in Advanced LIGO

用于先进 LIGO 低频改进的传感器

• 批准号: 1607385
• 负责人: Jens Gundlach
• 金额: $ 30万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1607385&HistoricalAwards=false
• 关键词: Sensors; Low; Frequency; Improvements; Advanced

Last February, Advanced LIGO detected gravitational waves for the first time, opening a new window to the universe.This award supports the development of new equipment to be deployed at the LIGO sites in Hanford, WA, and Livingston, LA. This consists of a high precision inertial tilt sensor to measure horizontal tilt independently from horizontal acceleration, which will improve Advanced LIGO seismic isolation, enabling robust operation of the interferometer under adverse environmental conditions. Research on tilt sensors will have a broader impact in areas such as seismology and geophysics by enabling measurement of tele-seismic tilts and tilt-free ground acceleration at frequencies as low as 10 mHz. The high precision angle readouts developed for these tilt sensors have a wide variety of applications in metrology and precision experiments. This award not only supports the development of a device for Advanced LIGO, but it also serves to maintain and strengthen synergistic activities of this table-top gravity group with the gravitational wave detection community. Importantly, this STEM research will train undergraduate and graduate students, and postdocs in building precision mechanical instruments.In LIGO's transition from Detector to Observatory, maintaining high duty cycles is a key challenge. Environmental conditions such as high wind, microseism and earthquakes were primarily responsible for significantly limiting the duty cycle during the first observing run. This is due to the inability of seismometers to distinguish between low-frequency tilt and translation, known as tilt-horizontal coupling. The ground-tilt sensors the group has developed have been demonstrated to improve the low-frequency seismic isolation in LIGO. Further improvement by making them smaller and more sensitive with interferometric readouts, would allow them to be mounted directly on the isolated platforms from which the LIGO mirrors are suspended, enabling a stronger and direct benefit to low-frequency differential motion of the mirrors. In addition, they may prove useful in measuring seismic tilts in the gravitational wave-signal band between 5-30 Hz, allowing cancellation of Newtonian noise, which is expected to limit sensitivity of aLIGO and future detectors.

去年二月，Advanced LIGO 首次探测到引力波，打开了一扇通向宇宙的新窗口。该奖项支持开发将部署在华盛顿州汉福德和路易斯安那州利文斯顿 LIGO 站点的新设备。它由高精度惯性倾斜传感器组成，可独立于水平加速度来测量水平倾斜，这将改善先进的 LIGO 隔震功能，使干涉仪能够在不利的环境条件下稳健运行。倾斜传感器的研究将能够在低至 10 mHz 的频率下测量远程地震倾斜和无倾斜地面加速度，从而对地震学和地球物理学等领域产生更广泛的影响。为这些倾斜传感器开发的高精度角度读数在计量和精密实验中具有广泛的应用。该奖项不仅支持高级 LIGO 设备的开发，而且还有助于维持和加强这个桌面重力组与引力波探测界的协同活动。重要的是，这项 STEM 研究将培训本科生、研究生以及博士后建造精密机械仪器。 在 LIGO 从探测器到天文台的过渡中，保持高占空比是一个关键挑战。大风、微震和地震等环境条件是首次观测运行期间显着限制占空比的主要原因。这是由于地震仪无法区分低频倾斜和平移（称为倾斜水平耦合）。该小组开发的地面倾斜传感器已被证明可以改善 LIGO 的低频隔震性能。通过使它们更小、干涉读数更灵敏，进一步改进将使它们能够直接安装在悬挂 LIGO 反射镜的隔离平台上，从而为反射镜的低频差分运动带来更强大和直接的好处。此外，它们可能有助于测量 5-30 Hz 之间引力波信号频带的地震倾斜，从而消除牛顿噪声，而牛顿噪声预计会限制 aLIGO 和未来探测器的灵敏度。