Cryogenic suspension design for a kilometer-scale gravitational-wave detector
Cryogenic suspension design for a kilometer-scale gravitational-wave detector
复制标题
千米级引力波探测器低温悬浮设计
DOI：
10.1088/1361-6382/abe9f3
复制
发表时间：
2021
影响因子：
3.5
通讯作者：
et al
中科院分区：
文献类型：
--
作者：
Ushiba Takafumi;Shinji Miyoki;et al
本文介绍了大型低温引力波望远镜KAGRA第一阶段的反射镜悬挂设计。镜面热噪声是Advanced LIGO和Advanced Virgo等室温引力波探测器的基本噪声之一。因此，为了进一步提高它们的灵敏度，需要降低热噪声。降低热噪声的一种有效方法是冷却反射镜。冷却反射镜必须克服许多技术挑战，例如低温冷却器引起的振动、悬架中的热漂移以及由于潜在故障机制数量增加而导致的占空比降低。我们的反光镜悬架有一个黑色涂层，使辐射冷却更有效。对于传导冷却，我们开发了超高纯度铝热链，它在保持足够小的弹簧常数的同时，具有高导热性。一个独特的倾斜调整系统，称为移动质量，用于调整反射镜的俯仰方向。采用大量程光反射位移传感器对提线车后坐质量和中间后坐质量进行阻尼控制。钐钴磁体用于线圈磁体致动器，以防止室温和低温之间的磁性发生显著变化。在本文中，我们的第一个低温有效载荷的设计和它的性能在bKAGRA阶段1进行了讨论。
We report the mirror suspension design for large-scale cryogenic gravitational wave telescope, KAGRA, during bKAGRA phase 1. Mirror thermal noise is one of the fundamental noises for room-temperature gravitational-wave detectors such as Advanced LIGO and Advanced Virgo. Thus, reduction of thermal noise is required for further improvement of their sensitivity. One effective approach for reducing thermal noise is to cool the mirrors. There are many technical challenges that must be overcome to cool the mirrors, such as cryocooler induced vibrations, thermal drift in suspensions, and reduction in duty cycling due to the increased number of potential failure mechanisms. Our mirror suspension has a black coating that makes radiative cooling more efficient. For conduction cooling, we developed ultra high purity aluminum heat links, which yield high thermal conductivity while keeping the spring constant sufficiently small. A unique inclination adjustment system, called moving mass, is used for aligning the mirror orientation in pitch. Photo-reflective displacement sensors, which have a large range, are installed for damping control on marionette recoil mass and intermediate recoil mass. Samarium cobalt magnets are used for coil-magnet actuators to prevent significant change of magnetism between room temperature and cryogenic temperature. In this paper, the design of our first cryogenic payload and its performance during bKAGRA phase 1 are discussed.