Vibration measurement in the KAGRA cryostat
Vibration measurement in the KAGRA cryostat
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DOI：
10.1088/0264-9381/31/22/224001
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发表时间：
2014-11
影响因子：
3.5
通讯作者：
Dan Chen;L. Naticchioni;A. Khalaidovski;K. Yamamoto;E. Majorana;Y. Sakakibara;C. Tokoku;Toshikazu Suzuki;N. Kimura;S. Koike;T. Uchiyama;S. Kawamura
中科院分区：
文献类型：
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作者：
Dan Chen;L. Naticchioni;A. Khalaidovski;K. Yamamoto;E. Majorana;Y. Sakakibara;C. Tokoku;Toshikazu Suzuki;N. Kimura;S. Koike;T. Uchiyama;S. Kawamura
日本引力波观测站KAGRA将在低温下运行，以减少热噪声。四个主镜及其悬挂系统（称为低温有效载荷）将在低温恒温器中冷却。低温恒温器和低温冷却器的振动会污染探测器的输出。噪声路径之一是在低温有效载荷和冷却有效载荷的低温冷却器之间由纯软金属制成的热链路。为了评估这种噪声幅度，我们在日本横滨的低温恒温器生产现场测量了低温下辐射屏蔽的振动。为此，我们开发了低温加速度计。在此基础上，计算了KAGRA干涉仪的噪声。我们的研究结果表明，与目前的设计，为KAGRA制定的地震噪声目标无法实现。最后，我们提出了一种可能的设计优化，这是为了达到标称灵敏度的检测器。
The Japanese gravitational wave observatory KAGRA will be operated at cryogenic temperatures to reduce thermal noise. Four main mirrors and their suspension systems, called cryogenic payloads, will be cooled in the cryostat. Vibrations of the cryostat and the cryocooler can contaminate the output of the detector. One of the noise paths is the heat link made from the pure soft metal between the cryogenic payload and cryocoolers to cool the payload. In order to evaluate this noise amplitude, we measured the vibration of the radiation shield at cryogenic temperatures at the cryostat production site in Yokohama, Japan. For this measurement, we developed cryogenic accelerometers. Based on the result of this measurement, we calculated the noise in the KAGRA interferometer. Our results show that with the current design, the seismic noise goal formulated for KAGRA cannot be achieved. Finally, we present a possible design optimization that is meant to reach the nominal sensitivity of the detector.