论文标题
紧凑的集成光学传感器和电磁执行器，用于重力波检测器中的振动隔离系统Kagra
Compact integrated optical sensors and electromagnetic actuators for vibration isolation systems in the gravitational-wave detector KAGRA
论文作者
论文摘要
本文报告了一个紧凑型模块的设计和特征，该模块集成了光学位移传感器和电磁执行器，用于与日本3公里的基线重力波检测器Kagra安装的振动 - 异化系统一起使用。在技术概念中，该模块属于类似模块的家族树，称为OSEM，用于其他干涉重力波探测器项目。在2016年Kagra初始测试运行之后，通过将插槽的间距从5 mm增加到15毫米，以避免机械干扰传感器标志的风险来修改传感器部分，即插槽传感器。我们确认传感器的性能与以前的设计相当。我们还确认传感器噪声与理论噪声预算一致。噪声水平在1 Hz时为0.5 nm/rthz，在10 Hz时为0.1 nm/rthz，传感器的线性范围为0.7 mm或更高。我们测量了执行器的响应为1 N/A，还测量了执行器线圈的电阻和电感，以确认与理论一致。还测量了不同自由度之间的耦合系数，并且显示出可以忽略的，在设计之间几乎没有变化。讨论了由于涡流损失引起的热噪声贡献的潜在问题。截至2020年，该站点正在运行42个模块。
This paper reports on the design and characteristics of a compact module integrating an optical displacement sensor and an electromagnetic actuator for use with vibration-isolation systems installed in KAGRA, the 3-km baseline gravitational-wave detector in Japan. In technical concept, the module belongs to a family tree of similar modules called OSEMs, used in other interferometric gravitational-wave detector projects. After the initial test run of KAGRA in 2016, the sensor part, which is a type of slot sensor, was modified by increasing the spacing of the slot from 5 mm to 15 mm to avoid the risk of mechanical interference with the sensor flag. We confirm the sensor performance is comparable to that of the previous design despite the modification. We also confirm the sensor noise is consistent with the theoretical noise budget. The noise level is 0.5 nm/rtHz at 1 Hz and 0.1 nm/rtHz at 10 Hz, and the linear range of the sensor is 0.7 mm or more. We measured the response of the actuator to be 1 N/A, and also measured the resistances and inductances of coils of the actuators to confirm consistency with theory. Coupling coefficients among the different degrees of freedom were also measured and shown to be negligible, varying little between designs. A potential concern about thermal noise contribution due to eddy current loss is discussed. As of 2020, 42 of the modules are in operation at the site.
