Speaker
Description
Technology validation for the ET-LF must be conducted in an extremely low-vibration, cryogenic environment to simulate adequate operational conditions. This harsh environment calls for a highly sensitive, cryogenic-compatible inertial sensor for vibration monitoring and reduction in the test facilities. To that end, cryogenic, vacuum-compatible, horizontal and vertical inertial sensors with a sensitivity of 10 fm/√Hz from 1 Hz at 20K are developed. This presentation collects the first validations conducted on the cryogenic sensors. Their proper operation under cryogenic conditions was first assessed by testing critical sub-components, such as the interferometric readout and suspension mechanisms, and by validating the sensor design's robustness to thermal variations. The vertical version of the sensors was integrated into a large-scale cryostat at the Institute for Gravitational Research (IGR) at the University of Glasgow to monitor vibration levels in this future ET technology validation facility. The vertical cryogenic interferometric inertial sensor operated perfectly down to 5.12K. Its measurements were validated over the range of 0.2 to 100Hz using witness sensors placed near the cryostat, proving its reliability in this harsh environment. Similar results were observed for the horizontal cryogenic sensor at 19K. Once the sensors proper operation under target conditions is demonstrated, their resolution is measured in a dedicated low-vibration cryogenic environment.